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Exploring meaningful nature experience, connectedness with nature and the revitalization of transformative education for sustainabilityZylstra, Matthew J. 04 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Humanity‘s growing separation from nature is central to the convergent social and ecological crises facing earth. This is both a psychological (e.g. perceptual, emotional) and physical (e.g. experiential) disconnect and is therefore better understood as a crisis in consciousness. This research arises out of an intense interest in how to alleviate humanity‘s fading connectedness with nature and, specifically, if meaningful nature experience is capable of healing the divisive ways in which humans tend to think, see and act in the world.
This study brings together four core themes: connectedness with nature (CWN), invasive alien species (IAS), and education for sustainability (EfS); each of which are explored around - and in relationship to - the core concept of meaningful nature experience (MNE).1 In doing so, this transdisciplinary research utilizes a theory of complexity to integrate diverse disciplinary perspectives by drawing upon: (conservation) ecology; (environmental-/eco-) psychology; (sustainability) education; and phenomenology as a guiding philosophy. Adopting an interpretivist and pragmatic approach, this research employs mixed methods (quantitative and qualitative/phenomenological analysis) to, firstly, uncover the essences which help describe what MNE feels like (how it appears in consciousness) and that which makes MNE what it is. Secondly, the study explores the relationship between MNE and CWN; the extent to which MNE is perceived to influence attitudes and environmentally responsible behaviour (ERB); and whether ecological change as experienced through IAS may affect MNE or, in turn, how MNE and CWN influence perceptions on IAS. Thirdly, the research examines the implications of the above for EfS: is there merit for integrating MNE and CWN in EfS? What would such a process look like and how can it be applied in a way which revitalizes EfS? Finally, as a form of heuristic inquiry, this study represents my process of conscious transformative learning. Reflective narratives are dispersed throughout this dissertation to capture this enriching personal journey. Research findings draw on over 200 unique accounts of MNEs which were elicited from: online and public questionnaires; in-depth interviews, email submissions and complemented by in-situ field observation and participation. The questionnaires and in-depth interviews also elicited responses on CWN, IAS and EfS.
The research finds that a MNE is triggered by an unexpected encounter with the 'non-ordinary‘ in nature. It is characterized by heightened sensory awareness (e.g. the beauty and detail of natural phenomena arrest our attention), intensified emotional (e.g. awe, amazement) and physiological responses (e.g. a 'rush‘). If an animal is involved, close proximity, extended length of time and reciprocity are key themes. For a MNE not involving an animal, perceived aliveness, vibrancy and energy pervading the land-/ sea-/ sky-scape is primary. As mind meets matter, one feels interrelatedness and a diminished sense of self. The privilege to commune with an 'other‘ (re)defines a person‘s being and belonging in the world. Synchronicity as a MNE is distinctive as an uncanny (e.g. numinous) experience of: insight; flow; guidance; a 'knowing‘; and interconnectedness. Respondents who have had a MNE exhibit a higher CWN; a positive correlation exists between frequency of MNE (fMNE) and CWN. Stronger correlations with CWN were found when a wild animal was involved in the MNE. Spiritual / religious practices positively correlate with fMNE and CWN with regular displays of gratitude toward nature returning slightly stronger correlations with CWN. Strongest correlations were found between the experience of synchronicity and CWN. A qualitative analysis of respondents‘ MNEs and their responses on how they perceive their MNE(s) to have changed them, found multiple and diverse mention of (newfound) appreciations of (inter)connectedness. This suggests that MNE acts as a conduit for CWN: one powerful MNE may be sufficient to catalyse the process; however, a higher fMNE increases the likelihood for heightened CWN. Such results affirm the idea that MNEs facilitate a relational worldview necessary for a consciousness attuned to CWN. CWN is considered to be a reliable predictor for ERB.
Over 90% agreement was found between respondents on the positive impact of MNEs in: shaping their views on nature and biodiversity; influencing their current behaviour and actions toward nature and the environment; and heavily influencing, changing or transforming their outlooks on life. The most common themes to emerge on how MNE was perceived to have changed respondents related to understanding of (inter)connectedness/interdependence; career choice; respect for nature / life; and new ways of seeing the world. This supports the premise that, by affectively bonding with nature, MNEs can motivate: ERB; life paths into conservation-minded careers; and serve as catalysts for personal growth and transformation, particularly when complemented with reflection, social (guided) facilitation and ecological literacy. The presence of IAS in landscape is likely to adversely affect MNE for stated reasons of ecological impacts, diminished 'naturalness‘, destructiveness and reduced diversity. Those viewing IAS as potentially enhancing their MNEs cite reasons of beauty, novelty and enjoyment. Respondents‘ CWN does not appear to affect perceptions of IAS; however, elevated CWN may invoke empathy, a sense of relatedness and appreciation of their intrinsic value as 'life‘. IAS may also feature in MNEs and, through experiential and metaphorical insight, can deliver newfound understandings of social and ecological connections as they relate to IAS.
Respondents concur that today‘s education does not prepare society to learn from MNE: overwhelming agreement was found on the societal and ecological benefits of an education that promotes understanding of MNE through a blend of intellectual concepts; experiential activities; values and ethics; and integrated learning approaches. Experiential nature-based activities were encouraged as vital EfS vehicles for enhancing sensory awareness; respect for nature; ecological knowledge and encountering connectedness. In-depth interviewees saw future EfS opportunities and solutions as focusing more on: participating with nature; bridging spirituality and science; facilitating 'openness‘ and shared experience; instilling values reflecting an interconnected reality; mentoring; contemporary rites of passage; and simply learning to live better. The essence of this research is an expanded appreciation of connectedness - embodying Nature, Community, Self, Source - and the manifold ways it is encountered through MNE. Revitalized EfS (realized through Theory edU) invites a consciousness that attends to an enlivening process of connecting, harmonizing and becoming. / AFRIKAANSE OPSOMMING: Hierdie studie bring vier kern temas na vore: verbintenis met die natuur (VMN), indringende uitheemse spesies (IUS), en opvoeding vir volhoubaarheid (OVV); waarvan elk verken is rondom – en in verhouding is tot die kern konsep van betekenisvolle natuur ervaring 2 (BNE). Deur dit te doen, wend hierdie transdisiplinêre studie 'n teorie van kompleksiteit aan om diverse dissiplinêre perspektiewe te integreer deur gebruik te maak van: bewarings ekologie; omgewings-/eko- sielkunde; onderwys; en femenologie as 'n rigtinggewende filosofie.
Deur 'n interpretatiewe en pragmatiese benadering aan te neem, is gemengde metodes (kwantitatief en kwalitatief / femenologiese analise) gebruik om eerstens die essensies wat help om te beskryf hoe BNE voel (hoe dit in die bewussyn voorkom) en dit wat BNE maak wat dit is, te ontbloot. Tweedens verken die studie die verhouding tussen BNE en VMN; die mate waartoe BNE beskou word om houdings en omgewings verantwoordelike gedragte beïnvloed (OVG); en of ekologiese verandering soos deur IUS ervaar word BNE kan affekteer, of, op sy beurt, hoe BNE en VMN persepsies van IUS kan beïnvloed. Derdens bestudeer die navorsing implikasies van die bogenoemde vir OVV: is daar meriete vir die integrasie van BNE en VMN in OVV? Hoe sal so 'n proses lyk en hoe kan dit toegepas word op 'n manier wat OVV weer nuwe lewe sal gee? Ten einde, as 'n vorm van heuristiese ondersoek, stel hierdie studie my proses van bewuste transformatiewe leer voor. Reflektiewe narratiewe is regdeur die proefskrif versprei om hierdie verrykende persoonlike reis vas te lê. Navorsing bevindinge gebruik meer as 200 unieke verklarings van BNE‘s wat aan die lig gebring is deur: aanlyn en publieke vraelyste; in-diepte onderhoude, e-pos indienings en dit is gekomplementeer deur in-situ veld observasie en deelname. Die vraelyste en in-diepte onderhoude het ook reaksies op VMN, IUS en OVV ontlok. Die navorsing het bevind dat 'n BNE word veroorsaak deur 'n onverwagste ontmoeting met die 'nie-gewone‘ in die natuur. Dit word gekarakteriseer deur verhoogde sensoriese bewustheid (bv. die prag en besonderhede van natuurlike verskynsels beset ons aandag), versterkde emosionele (bv. verwondering en verbasing) en psigologiese reaksies (bv. 'n stormloop). Indien 'n dier betrokke is, is nabyheid, verlengde duur van tyd en wederkerigheid sleutel temas. Vir 'n BNE wat nie 'n dier insluit nie, is waarneembare lewendigheid, dinamiek en energie wat die landskap / see / luglandskap deurdring primêr. Soos wat die gees die stof ontmoet, voel 'n mens 'n onderlinge verband en 'n verminderde sin van die self. Die voorreg om in noue aanraking met 'n 'ander‘ te kan wees (her)definieër 'n persoon se wese en behoort in die wêreld. 'Synchronicity‘ as 'n BNE is kenmerkend as 'n ongelooflike (bv. numineuse) ervaring van: insig, vloei, leiding; 'n 'wete‘; en onderlinge verbintenis.
Respondente wat 'n BNE gehad het, het 'n hoër VMN getoon; 'n positiewe korrelasie bestaan tussen die frekwensie van BNE (fBNE) en VMN. Sterker korrelasies met VMN was gevind in die geval waar 'n wilde dier in die BNE betrokke was. Geestelike / religieuse praktyke korreleer positief met fBNE en VMN waar gewone openbarings van dankbaarheid tot die natuur effens sterker korrelasies met VMN terugbring. Die sterkste korrelasies was gevind tussen die ervaring van 'synchronicity‘ en VMN. 'n Kwalitatiewe analise van respondente se BNE‘s en hul response van hoe hulle hul BNE(s) as dit wat hul verander het, beskou, het veelvoudige en diverse antwoorde van (nuutgevonde) erkennings van (onderlinge) verbintenis navore gebring. Dit dui daarop dat BNE as 'n toevoerbuis vir VMN optree: een kragtige BNE mag voldoende wees om die proses te kataliseer; aan die anderkant verhoog 'n hoër fBNE die waarskynlikheid vir verhoogde VMN. Sulke resultate bevestig die idee dat BNEs 'n relasionele wêreldbeskouing is wat nodig is vir 'n bewustheid wat ingestel is vir VMN. VMN word as 'n betroubare voorspelling vir OVG beskou.
Meer as 90% van respondente was in ooreenstemming ten opsigte van die positiewe impak van BNEs in: die vorming van hul beskouings van die natuur, biodiversiteit; beïnvloeding van hul huidige gedrag en aksies tot die natuur en die omgewing; en hoe dit hul vooruitsigte op die lewe hewig beïnvloed, verander of transformeer. Die meesal gemene temas wat ontluik het, was oor die beskouing van hoe BNE respondente se verstaan aangaande (onderlinge)verbintenis / onafhanklikheid; beroepskeuse; respek vir die natuur / lewe; en nuwe maniere om na die wêreld te kyk, verander het. Dit ondersteun die uitgangspunt, dat deur affektiewelik met die natuur in verbinding te tree, BNEs gemotiveer kan word: OVG; lewens paaie tot bewaring-gesinde beroepe; en as katalisators dien vir persoonlike groei en transformasie, veral as dit met refleksie, sosiale (begeleide) fassilitering en ekologiese geletterdheid gekomplimenteer word.
Die teenwoordigheid van IUS in 'n landskap kan waarskynlik BNE nadelig affekteer weens verklaarbare redes van ekologiese impakte, afneembare 'natuurlikheid', verwoestendheid en verminderde diversiteit. Diegene wat IUS as iets positief tot hul ervaring beskou, verskaf redes soos skoonheid, nuutheid en genot. Dit wil voorkom of deelnemers se VMN nie algemene persepsies van IUS affekteer nie; alhoewel, verhoogde VMN empatie, verwantskap en waardering vir hul intrinsieke waarde as 'lewe' mag oproep. IUS mag ook in BNE vertoon en deur ervarings- en metaforiese insig, kan dit waardevolle nuut-bevinde begrippe van sosiale en ekologiese verbande soos wat hulle aansluit by die probleem van IUS, lewer. Respondente is dit eens dat vandag se onderwys nie die samelewing voorberei om te leer van BNE nie: oorweldigende ooreenstemming was gevind aangaande die maatskaplike en ekologiese voordele van onderwys wat die verstaan van BNE bevorder deur middel van 'n vermenging van intellektuele konsepte; ervarings leeraktiwiteite; waardes en etiek; en geïntegreerde leer benaderings. Ervarings leer natuur-gebaseerde aktiwiteite was aangemoedig as essensiële middels vir OVV vir die verhoging van sensoriese bewussyn; respek vir die natuur, ekologiese kennis en die teëkoming van verbintenis. In-diepte ondervraagdes het geleenthede en oplossings vir toekomstige OVV gesien in terme van 'n groter fokus op: deelname aan die natuur; die orbruging van spiritualiteit en wetenskap; fassilitering van 'oopheid‘ en gedeelde ervaring; vestiging van waardes wat 'n onderlinge verbonde realiteit reflekteer; mentorskap; kontemporêre deurgangsrites; en om eenvoudig te leer om beter te lewe.
Die kern van hierdie navorsing behels 'n toenemende waardering van verbintenis – beliggaming van die Natuur, Gemeenskap, Self, Bron – en die menigvuldige maniere waar op dit deur BNE ondervind is. Hernude OVV (soos ontdek deur Theory edU) nooi 'n bewustheid uit wat aandag skenk aan 'n verlewendige proses van verbintenis, harmonisering en wording.
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Development of a Biotope Quality IndexBredenhand, Emile 04 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: As the world’s human population increases, more pressure is placed on the management of natural
resources. In response, we need an efficient means of monitoring, not only the quantity of these
resources but also their quality. No comprehensive standard metric has been developed to assess
environmental quality of a biotope, or to define the nature and extent of environmental degradation at
this spatial scale. Currently in conservation management, various landscapes are being evaluated for
spatial heterogeneity, by making use of species surrogates such as species richness, relative abundance,
diversity indices and phylogenetic indices, as well as environmental surrogates. These values are then
used towards conservation, where those systems with high intrinsic heterogeneity are usually considered
more important than those with low heterogeneity at least when given the choice between the two. Yet,
the actual quality of the biotopes within the landscapes is rarely taken into consideration. This study
therefore develops and tests a Biotope Quality Index (BQI) to study this point in depth. The BQI makes
use of arthropod assemblages as bioindicators of the level of disturbance within a biotope.
Firstly, I summarize the literature on the concept of environmental health, and define it as “An ecosystem
is healthy, if it can sustain an optimal number of species with optimal population sizes and their
ecological processes, thus providing and optimal heterogeneous sustainable system with sufficient
resources, and indicated adequate resistance when under perturbational stress, but still allowing natural
succession to take place” Against this background, I then review the use of certain Arthropoda as
bioindicators, as arthropods are small, mobile, environmentally sensitive, easily sampled, and readily
available. These features together make arthropods good subjects for testing the BQI. I then compare the BQI with diversity indices currently used as surrogates of biotope quality. The
outcome was that the BQI stood out as a significantly better indicator than the currently available indices
for assessing environmental quality of a biotope. Furthermore, during the selection process, I also tested
the use of guilds for BQI evaluation, and found that the scavenger (represented by Formicidae) and
decomposer (represented by Collembola) guilds were the most significant. The effect of seasonality was
also tested. I found the best results with the BQI were when data are pooled from all seasons of the year.
A case study, making use of the BQI evaluation, was conducted at a site in the Cape Floristic Region,
South Africa (Jonkershoek Valley). BQI results suggested that the agricultural management and tourism
within the locality might have an effect on biotope quality. This study has shown that use of the BQI is a
useful and practical management tool for evaluating environmental quality of a biotope towards
conservation management. / AFRIKAANSE OPSOMMING: Met die vermeerdering van mense op die Aarde, wat meer druk plaas op ons natuurlike hulpbronne en
omgewing is daar ‘n aanvraag na doeltrefende maniere wat nie net die kwantiteit maar ook die kwaliteit
van die hulbron evalueer. Geen betroubare standard bestaan om biologiese kondisies of die
kwaliteit van n omgewing te meet nie. Heidiglik maak wetenskaplikes staat op die bepaling van
diversiteit en ander voogde soos spesies rykheid en diversiteit indeksies as voog vir kwaliteit.
Die waardes word dan gebruik binne die omgewings bestuur praktyke en bevooroordeel
omgewings met ‘n hoë diversiteit, terwyl die kwaliteit van omgewing skaarslik na gekyk word.
Hiervolgens, onwikkel ons n Omgewings Kwaliteit Indeks (OKI), wat gebruik maak van
Arthropoda saamestellings as bioindikator van die vlak van verval binne ‘n omgewing. Verder
sluit die tesis n literatuur studie van die omgesings gesondheid teorie, en die gebruik van
arthropoda as bioindikators. As basis van die studie, definieër ons ‘n gesonde omgewings as ‘n
omgewing wat’ n optimal hoeveelheid spesies en hulle ekologiese prosesse kan handhaf, en
daarom verwys na ‘n diverse onderhoubare sisteem met genoegsame hulpbronne en kan
genoegsame weerstand bied onder omgesings stres, maar gee geleentheid vir naturlike suksesie
om plaas te vind
Ons het verder die OKI getoets teen ander diversiteit’s indeksies, waar ons gevind het dat die
OKI evaluering ‘n statistiese beklemtonde verskil toon as bioindikator van omgewings kwaliteit.
Verder het ons voorkeer getoets, in gedrags groupe en gevind dat die versamellaars groep
(verteeenwoordig deur Formicidae) en die afbrekers groep (verteenwoordig deur Collembola) die
beste resultate toon. Seisoene het ook ‘n uitwerking en ons het gevind die groupeering van data
ingesamel oor alle seisoene die beste resultate getoon. ‘n Ondersoek studie wat gebruik maak van die OKI evalueering, was gekondakteer in die
Jonkershoek valei en het getoon dat die landbou plaagbestuur en toerusme ‘n negatiewe effek het
op die omgewing. Verder het die OKI evalueering getoon dat aanplanting van Denne plantasies
die kwaliteit van ‘n omgewing verlaag. Die studie het verder getoon dat die OKI evalueering ‘n
betroubare evalueerings metode is vir die bestuur van ‘n omgewings, terwyl die diversiteits
indeksies nie geskik is as bioindikator van omgewings kwaliteit nie.
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Acoustic profiling of the landscapeGrant, Paul Brian Charles 04 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Soft, serene insect songs add an intrinsic aesthetic value to the landscape. Yet these songs also
have an important biological relevance. Acoustic signals across the landscape carry a multitude
of localized information allowing organisms to communicate invisibly within their
environment. Ensifera are cryptic participants of nocturnal soundscapes, contributing to
ambient acoustics through their diverse range of proclamation songs. Although not without
inherent risks and constraints, the single most important function of signalling is sexual
advertising and pair formation. In order for acoustic communication to be effective, signals
must maintain their encoded information so as to lead to positive phonotaxis in the receiver
towards the emitter. In any given environment, communication is constrained by various local
abiotic and biotic factors, resulting in Ensifera utilizing acoustic niches, shifting species songs
spectrally, spatially and temporally for their optimal propagation in the environment. Besides the importance of Ensifera songs from an ethological point of view, the
multitude of species-specific signals provide an acoustic tapestry representing species diversity
across ecological gradients and over time. Acoustic inventorying and monitoring of the
landscape can reflect the environmental status of ecological systems, from natural to disturbed
by human influence. In contrast to traditional survey techniques, sound recording and
interpretation is a non-invasive method that allows for the detection and classification of highly
cryptic, yet insightful indicators of ecosystem change. Here, acoustic monitoring was used
across diverse ecological gradients to improve understanding of species diversity patterns, and
how they change in response to both natural gradients and in response to the human dominated
landscape mosaic.
This study was undertaken in three geographic locations from tropical rain forest of
Brunei, Borneo, to the landscapemosaic of plantation forestry in KwaZulu-Natal, South Africa, and to the botanically rich, mountain fynbos region of the Cape Floristic Region, also in South
Africa. Each region provided a diverse and particular landscape to test the value of acoustic
surveys for determining local diversity patterns across natural gradients and to assess the value
of the technique for assessing the impact human influence across landscapes.
In tropical rainforests, an entire acoustic guild was investigated to determine how
acoustic species partition their acoustic communication channels spectrally, temporally and
spatially, to avoid acoustic interference. The overall assemblage showed considerable spectral
partitioning. Diurnally active species showed low temporal niche overlap, whereas nocturnal
species did not utilize temporal partitioning. Lack of nocturnal temporal partitioning suggests
other mechanisms of acoustic avoidance are sufficient to avoid acoustic overlap, or that there
are insufficient cues to partition nocturnal acoustic environments. Acoustic species also utilized
spatial partitioning, with distinct acoustic assemblages at vertical heights and with elevation.
Utilization of a range of different strategies allow many species to communicate with
conspecifics with little or no interference from other species in a signal rich environment. Acoustic profiling was also undertaken in KwaZulu-Natal, South Africa, across a
plantation forestry landscape mosaic with diverse ecological gradients containing both alien
and indigenous vegetation, as well as boarding large natural protected areas. Areas covered in
alien timber or non-endemic grass were devoid of acoustic signals. Managed areas that were
mowed and heavily grazed were not effective in maintaining the natural complement of
nocturnal acoustic species. Within natural vegetation patches inside plantations, acoustic
species richness increased with plant heterogeneity and patch size. Patches of indigenous
vegetation within the plantation matrix effectively reduced the contrast of transformed
landscapes with surrounding natural areas, with indigenous forest patches containing a highly
characteristic acoustic species assemblage. Within the botanically rich, mountain fynbos region of the Cape Floristic Region,
acoustic profiling was conducted across gradients of elevation, season and vegetation. Across
these gradients, katydid acoustic signals were identified and characterized for the first time.
This resulted in the discovery of two new katydid species and a novel sound producing structure
in a carabid beetle, a species previously unknown to produce sound. Acoustic diversity across
seasonal and elevational gradients increased with increasing temperatures. Climatic variability
along the elevational gradient produced variation in seasonal phenology. Katydids also utilized
high frequency acoustic signals, which is probably an adaptation to overcome background
noise from wind, so prevalent in this area. Furthermore, despite producing conspicuous signals
for mate attraction and pair formation, katydids were found not to be part of bat-eared fox diet,
an insectivorous, nocturnal predator that uses its characteristic large ears to detect sounds made
by invertebrate prey. This study shows the value of using acoustic emissions from katydids to identify
acoustic diversity patterns across ecological gradients and in response to human impacts on the
landscape. / AFRIKAANSE OPSOMMING: Sagte, rustige insekliedjies voeg ‘n intrinsieke estetiese waarde aan die landskap. Tog is hierdie
liedjies ook van belangrike biologiese waarde. Akoestiese seine oor die landskap dra ‘n
magdom plaaslike inligting wat organismes in staat stel om onsigbaar te kommunikeer binne
hul omgewing. Langhoringsprinkane is kriptiese deelnemers van die nagtelike klankomgewing
en dra by tot die omringende akoestiek deur hul verskeidenheid van proklamasieliedjies.
Alhoewel dit nie sonder inherente risiko’s en beperkings is nie, is die belangrikste funksie van
seine seksuele advertering en paarvorming. Vir akoestiese kommunikasie om effektief te wees,
moet seine hul geënkodeerde inligting handhaaf, sodat dit sal lei tot positiewe fonotaksis in die
ontvanger teenoor die emittor. In enige gegewe omgewing, word kommunikasie beperk deur
verskeie plaaslike abiotiese en biotiese faktore. Dit lei tot die gebruik van akoestiese nisse deur
langhoringsprinkane, wat hulle liedjies spektraal, ruimtelik en temporeel aanpas vir optimale
verspreiding in die omgewing. Benewens die belang van die langhoringsprinkaan liedjies uit ʼn etologiese oogpunt,
bied die menigte spesie-spesifieke seine ʼn akoestiese tapisserie wat spesiesdiversiteit
verteenwoordig oor ekologiese gradiënte en oor tyd. Akoestiese opname en monitering van die
landskap kan die omgewingstoestand van ekologiese stelsels weerspieël, van natuurlike tot
menslik versteurde stelsels. In teenstelling met tradisionele opnametegnieke, is klankopname
en interpretasie ʼn nie-indringende metode wat dit moontlik maak om hoogs kriptiese, nog
insiggewende indikators van ekosisteemverandering op te spoor en te klassifiseer. In hierdie
studie is akoestiese monitering gebruik oor diverse ekologiese gradiënte om ons begrip te
verbeter van spesies diversiteitspatrone, en hoe dit verander in reaksie op beide natuurlike
gradiënte en in reaksie op die menslik gedomineerde landskapmosaïek. Hierdie studie is onderneem in drie geografiese liggings: tropiese reënwoud in Brunei,
Borneo, die landskapmosaïek van plantasiebosbou in KwaZulu-Natal, Suid-Afrika, en die
plantryke, bergfynbos-streek van die Kaap Floristiese Streek, ook in Suid-Afrika. Elke streek
het 'n diverse en besondere landskap verskaf om die waarde van akoestiese opnames te toets
vir die bepaling van plaaslike diversiteitspatrone in natuurlike gradiënte, asook om die waarde
van die tegniek te bepaal vir die beoordeling van die impak van menslike invloed oor
landskappe. In tropiese reënwoude, is 'n hele akoestiese gilde ondersoek om te bepaal hoe akoestiese
spesies hul akoestiese kommunikasiekanale spektraal, ruimtelik en temporeel verdeel om
akoestiese inmenging te vermy. Die algehele groep het aansienlike spektrale verdeling getoon.
Dagaktiewe spesies het lae temporele nisoorvleueling getoon, terwyl nagtelike spesie nie
temporele verdeling benut het nie. Gebrek aan nagtelike temporele verdeling dui daarop dat
ander meganismes van akoestiese vermyding voldoende is om akoestiese oorvleueling te
vermy, of dat daar onvoldoende seine is om nagtelike akoestiese omgewings te verdeel.
Akoestiese spesies het ook ruimtelike verdeling benut, met verskillende akoestiese
spesiesversamelings op vertikale hoogtes en met hoogte bo seevlak. Die gebruik van 'n
verskeidenheid van strategieë maak dit moontlik vir spesies om te kommunikeer met min of
geen inmenging van ander spesies in 'n seinryke omgewing. Akoestiese profielsamestelling is ook onderneem in KwaZulu-Natal, Suid-Afrika, oor
'n plantasiebosbou landskapmosaïek met diverse ekologiese gradiënte wat beide uitheemse en
inheemse plantegroei, sowel as groot, natuurlike, beskermde gebiede ingesluit het. Gebiede
wat bestaan het uit uitheemse timmerhoutbome of nie-endemiese gras, was heeltemal sonder
akoestiese seine. Bestuursgebiede wat gesny en swaar bewei was, het nie doeltreffend die
natuurlike komplement van nagtelike akoestiese spesies gehandhaaf nie. In natuurlike plantegroei fragmente binne plantasies, het akoestiese spesiesrykheid toegeneem met
plantverskeidenheid en fragmentgrootte. Fragmente van inheemse plantegroei binne die
plantasiematriks het effektief die kontras van getransformeerde landskappe met omliggende
natuurlike gebiede verminder, en inheemse woudefragmente het hoogs kenmerkende
akoestiese spesiesversamelings gehad. Binne die plantryke bergfynbosstreek van die Kaap Floristiese Streek, was akoestiese
profielsamestelling gedoen oor gradiënte van hoogte bo seevlak, seisoen en plantegroei. Oor
hierdie gradiënte, is langhoringsprinkaan akoestiese seine geïdentifiseer en gekenmerk vir die
eerste keer. Dit het gelei tot die ontdekking van twee nuwe langhoringsprinkaan spesies en 'n
nuwe klankvervaardiging struktuur in 'n Carabid kewer, 'n spesie wat nie voorheen bekend was
om klank te produseer nie. Akoestiese diversiteit oor gradiënte van seisoen en hoogte bo
seevlak het toegeneem met toenemende temperature. Variasie in klimaatstoestande oor die
gradiënt van hoogte bo seevlak het variasie in seisoenale fenologie veroorsaak.
Langhoringsprinkane het ook hoë frekwensie akoestiese seine benut, wat waarskynlik 'n
aanpassing is om agtergrondgeraas van die wind, wat so algemeen is in hierdie gebied, te bowe
te kom. Verder, ten spyte van die vervaardiging van opvallende seine vir maataantrekking en
paarvorming, het langhoringsprinkane nie deel gevorm van die bakoorjakkals se dieet nie.
Hierdie is 'n insekvretende, nagtelike roofdier wat gebruik maak van sy kenmerkende groot ore
om klanke op te spoor wat gemaak word deur invertebraatprooi. Hierdie studie toon die waarde van die gebruik van akoestiese seine van
langhoringsprinkane om akoestiese diversiteitspatrone te identifiseer oor ekologiese gradiënte
en in reaksie op menslike impakte op die landskap.
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Management of Acacia species seed banks in the Table Mountain National Park, Cape Peninsula, South AfricaJasson, Rene 12 1900 (has links)
Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2005. / Within the Table Mountain National Park (TMNP), Western Cape, South Africa, various management practices have been undertaken in the removal of alien vegetation. While considerable success in the control of alien plants is evident from the removal of standing plants, it is not known if this effort has actually made any long-term difference in the effort to eliminate alien vegetation from the TMNP. This is because no coordinated effort has been made to assess the extent of the alien seed bank, nor the effect that clearing (including the use of fire) has on this seed store.
This study investigates the extent of pre- and post-fire Acacia saligna seed banks under differing stand ages, differing clearing techniques and different habitats in the Cape Peninsula National Park. Firstly, the focus is on two alien plant management techniques: The first technique involves clearing and stacking of biomass for burning during winter (stack burn technique), the second technique involves burning of standing alien plants (standing/block burn technique) to decrease heat release at the surface. Secondly, the extent of Acacia species seed banks along the Silvermine River is also investigated with the aim of determining the extent of alien seed stores in this habitat and therefore the long-term restoration potential of the riparian corridor.
The primary question addressed in the first study is: “Under what clearing technique will most of the alien seed bank be reduced?” The secondary question reads: “Is seed bank density and distribution directly related to age of dense infestation of the alien vegetation stand and habitat?” The primary question addressed in the second study is: “What is the vertical, lateral and longitudinal distribution and density of Acacia species seed banks along the Silvermine River?” The secondary question reads: “Is seed density and distribution influenced by above ground density of alien vegetation?”
In both riparian and terrestrial systems, alien soil seed banks accumulate in high densities where aboveground alien Acacia vegetation is dense. Most of the seed occurs in the upper soil layer, but seed density decreases with depth with an exception of a high seed density at a low depth in one of the samples in the riparian system. Intense fires are most effective in reducing seed stores and removing aboveground alien vegetation in both riparian and terrestrial fynbos systems.
After burns, both stack and stand burns have shown a significant decrease in seed density especially in the upper layers but there is still much seed that remained in the matrix area between stacks. The cooler winter burns resulted in less destructive, lower temperatures that aided higher seedling recruitment. Mature stands of Acacia saligna tend to have greater seed stores than immature stands and habitats with deep colluvial soils have a greater density and also greater vertical distribution of seeds.
The vertical distribution of the riparian system differed from the fynbos terrestrial system in that seeds were found down to lower depths. Along the river, seed density also increased laterally with more seeds occurring in the terrrestrial sections than in the channel. Seed density increased with longitudinal distribution with more seeds occurring at the sites in the lower catchment than upper catchment. Managers should be aware that fire is needed to reduce the seed bank in both riparian and terrestrial fynbos systems. The cooler winter stack burns is the best option as it results in less destructive, lower temperatures that aids higher seedling recruitment. It is important to know the site history as age of dense infestation, number of fires and geology of site could influence seed bank density. In riparian systems the vertical distribution of seed is deeper than in the fynbos area. In order for clearing to be effective it is imperative that follow-up takes place and should be done prior to flowering to stop reseeding.
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Small mammal communities in the transformed landscapes of the Western Cape lowlands and their role in alien invasion into fynbos remnantsMugabe, Chapangara James 12 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. / The fynbos eco-region in the Western Cape lowlands has been extensively transformed by
anthropogenic activities such as agriculture and urban development, as well as invasive alien
plants. Elandsberg Private Nature Reserve and Farms lies on Swartland Alluvium Fynbos and
has been largely fragmented by agricultural crop production, whilst Riverlands Nature
Reserve together with the Pella Research Site, which lie on Atlantis Sand Fynbos, are under
severe threat from the invasive woody alien Port Jackson Willow (Acacia saligna) which
forms dense stands in the lands adjacent the nature reserve. Habitat transformation has
resulted in subsequent loss of habitat and a reduction in habitat value for small mammal
communities by creating a mosaic of optimal and sub-optimal habitats. The success of A.
saligna is, in part, attributed to its production of copious amounts of small hard-shelled seeds
and well established soil seed banks. In the first part of this study we investigated the effect
of habitat transformation on resident small mammal communities by comparing small
mammal species richness, diversity and abundance between natural and transformed habitats
as well as between the two vegetation types. We also investigated the population
demographics of the striped mouse (Rhabdomys pumilio) in the different habitats. Our study
shows that whilst fragments of natural habitats, especially at Riverlands and Pella, may be
playing an important role in harbouring rare and possibly endangered species, transformed
habitats are also important as secondary habitats providing both cover as well as seasonal
food resources. Reproduction and body condition in R. pumilio were dependent on seasonal
changes such as availability of water and food resources in the habitats. The second part of
this study was carried out to investigate the effect of alien plant invasion on the resident small
mammal communities at Riverlands Nature Reserve and to determine the role of small
mammals in the removal and predation of A. saligna seeds. Rodent species richness, diversity
and abundance were very low in the A. saligna stands compared to the adjacent fynbos
vegetation. The interaction of rodents with seeds (removal or predation) was dependent upon
seed size and seed abundance in the habitats. Whilst rodents may play an important role in
predator limitation in the acacias, it is also possible that they may be playing a significant role
in dispersing the seeds of acacias into the fynbos. More work is required to fully understand
the role small mammals play in seed predation, dispersal and limitation in alien invaded
fynbos systems.
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Spatial and temporal distribution of false codling moth across landscapes in the Citrusdal area (Western Cape Province, South Africa).Stotter, Robert L. 03 1900 (has links)
Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2009. / The false codling moth (FCM), Thaumatotibia leucotreta (Meyrick)
(Lepidoptera: Tortricidae), is an indigenous pest of citrus fruit in southern Africa, and is a
pest of high phytosanitary concern, impacting negatively on the export of fresh citrus
fruit from South Africa to some international markets. FCM is a particularly serious pest
in the Citrusdal area in the Western Cape Province of South Africa. FCM is known to
infest most types of citrus, with navel oranges being particularly prone to attack, whereas
lemons are not considered to be a favoured host. Conventional control strategies that rely
on the use of insecticides are of limited use due to high levels of insecticide resistance in
FCM populations. Mating disruption, the Sterile Insect Technique (SIT) and the
integration of different control techniques are options that are currently being adopted.
Little is known about FCM host preferences in this geographical area, or about its
dispersal capacity. The ability of FCM to migrate between various host patches,
including citrus orchards and indigenous fynbos vegetation, and its ability to maintain a
viable population in alternative host plants when there is no fruit available for infestation
in citrus orchards has not been well studied. Knowledge of these largely behavioural
facets is important in planning an effective control strategy for FCM.
Towards addressing this dearth of knowledge, FCM pheromone traps were set out in
transects in the Citrusdal area. These transects included citrus orchards, and extended
beyond citrus orchards, to include a range of habitat types and elevational gradients. This
provided a grid to assess the spatial and temporal distribution of male FCM in the area.
In addition, intensive sampling and inspection of potential host plant material was
undertaken in the area in an attempt to identify any alternative host plants.
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Habitat use and diet selection of reintroduced white rhinoceros (Ceratotherium simum) in Pafuri, Kruger National ParkPedersen, Gayle 03 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology))--Stellenbosch University, 2009. / ENGLISH ABSTRACT: In 2005, six white rhinoceros (Ceratotherium simum) were reintroduced into Pafuri, in
the far northern section of Kruger National Park (KNP), South Africa, as part of a
large mammal reintroduction project. All six individuals were fitted with horn radio
transmitters. Rhinos have been absent from Pafuri for over a century, and this project
aimed to establish a breeding nucleus in the area. The aim of this study was to
monitor post-release movement and habitat use of these animals within the 203 km2
study area and assess the short term success of the re-introduction project as well as
the suitability of the five landscape types in Pafuri as a habitat for white rhinoceros.
Habitat suitability and selection was assessed at two ecological hierarchical scales: 1)
landscape system, analysed further down to the spatial scale of range and territory
establishment, and 2) feeding station for diet selection. Rhinos were tracked for 12
months and a database of 719 sighting records was compiled. These data were used to
determine the utilisation of and preference between the Pafuri landscape types, using
preference indices that compare utilisation versus availability. An a-LoCoH
nonparametric kernel method was used to calculate home ranges and utilisation
distributions of each rhino. Feeding surveys were attempted by backtracking along
fresh rhino feeding paths and recording the grass species present and eaten in 0.7 m x
0.7 m quadrats. Faecal samples were collected and analysed using microhistological
techniques and dietary composition was assessed for each rhino.
Landscape preference analyses showed that the rhinos favoured Colophospermum
mopane Shrubveld on calcrete in the dry season, and the Punda Maria Sandveld in the
wet season. The territory establishment of the dominant bull was substantially larger
(44.8 km²) than those of adult male rhinos in the rest of KNP. Ranging areas of the
mature females (17 – 25.4 km²), were consistent with sizes of previous studies. The
two sub-adults ranged far more extensively, establishing an 84.1 km² annual range
during the study period. The annual diet consisted of mostly perennial grass species,
with moderate grazing value species dominating for most of the year. Dietary
analyses showed that Schmidtia pappophoroides, Eragrostis superba, Enneapogon cenchroides,
Cenchrus ciliaris and Stipagrostis uniplumis were the primary grass species consumed.
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This study demonstrated that the Pafuri rhinos are behaving similarly to rhinos
established in other areas, with movements around the landscapes being primarily
influenced by rainfall and permanent water sources, and the high quality grazing that
is more abundant in the wet season. Their range and territory sizes were inevitably
large, for a low density area, but not uncommonly so. The most significant outcome
of this study was the preference shown for the Colophospermum mopane Shrubveld on
calcrete landscape that is classed as unique within South Africa, and was also ranked
as ‘avoided’ by the earlier KNP studies into landscape preferences of rhinos. The
grass cover in Pafuri, although sparse and very dry, contained a diversity of low to
high grazing value grasses that the rhinos appeared to exploit to the best of their
ability. The abundance of moderate grazing value species in their diets, and the low
number of low grazing value species suggests that they are maximising the
opportunities to graze on nutritious grasses when they are available. Our findings
suggest that the Pafuri area is suitable for the establishment of a small breeding
nucleus of white rhinos. The abundance of permanent water, in the form of springs,
is a great advantage however, the potential for bush encroachment into grasslands in
areas of such low rainfall needs to be considered if the population continues to grow
at the current rate. The birth of two new calves in 2008 confirms that these rhinos
have settled and adapted to their new habitat, and is a very promising sign for the
future of this increasing subpopulation. / AFRIKAANSE OPSOMMING: In 2005 is ses wit renosters (Ceratotherium simum) hervestig in Pafuri in die noordelike
gedeelte van die Kruger Nasionale Park (KNP), Suid-Afrika, as deel van ‘n groot
soogdier hervestigings projek. Al ses individue is gemerk met horing radioseintoestelle.
Renosters kom vir al meer as ‘n honderd jaar nie meer in Pafuri voor nie
en hierdie projek was daarop gemik om ‘n teel-nukleus in hierdie gesied te vestig. Die
doel van hierdie studie was om die verspreiding van die renosters na loslating en
habitat-gebruik binne die 203 km2 studie-omgewing te monitor, om die korttermyn
sukses van die hervestigings program te evalueer en ook te kyk na die gepastheid van
die vyf landskap-tipes in Pafuri as ‘n geskikte habitat vir die wit renosters.
Habitatgepastheid en seleksie is geëvalueer volgens twee ekologiese hiërargiese skale:
1) landskapsisteem, wat in meer resolusie tot die ruimtelike skaal van reikwydte en
omgewingsvestiging geanaliseer is, en 2) voedings-stasie vir dieet-seleksie. Renosters
is vir 12 maande gevolg en ‘n databasis wat 719 waarneming-rekords bevat, is
opgestel. Laasgenoemde data is gebruik om die gebruik en voorkeur vir die Pafuri
landskap tipes te bepaal met behulp van voorkeur-indikators wat die gebruik met
beskikbaarheid vergelyk het. ‘n a-LoCoH nie-parametriese kern metode is gebruik
om die reikwydte en gebruiksverspreidings van elke renoster te bereken.
Voedingsopnames is gedoen deurdat vars renoster voedings-paadjies terugwaarts
gevolg is en die grasspesies teenwoordig en waarop gevoed is, in 0.7 m x 0.7 m
kwadrante te bepaal. Mismonsters is versamel en geanaliseer deur gebruik te maak
van mikro-histologiese tegnieke en voedingswaarde-samestellings is vasgestel vir elke
renoster .
Landskapsvoorkeur analises dui daarop dat die renosters in die droë seisoen
Colophospermum mopane struikveld wat op kalkreet groei verkies en die Punda Maria
Sandveld in die reën seisoen. Die terrein vestiging van die dominanate bul was
aansienlik groter (44.8 km²) in vergelyking met die volwasse bul renosters in die res
van die KNP. Reikwydte van die volwasse koeie (17 – 25.4 km²) was
ooreenstemmend met dié van vorige studies. Die reikwydte van die twee subvolwassenes
het baie meer gevarieer, deurdat ‘n 84.1 km² jaarlikse reikwydte gedek
was binne die studie periode. Die jaarlikse dieet het meestal bestaan uit meerjarige
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grasspesies, met spesies met matige weidingswaarde wat oorheers vir meeste van die
jaar. Voedingswaarde analises dui daarop dat Schmidtia pappophoroides, Eragrostis
superba, Enneapogon cenchroides, Cenchrus ciliaris en Stipagrostis uniplumis die primêre gras
spesies was waarop gewei word.
Die studie het bewys dat die Pafuri renosters soortgelyke gedragspatrone vertoon het
as renosters in ander gevestigde gebiede, deurdat bewegings binne die landskap
hoofsaaklik beïnvloed word deur reënval en permanente waterbronne, asook die hoë
gehalte weidingsbronne beskikbaar gedurende die reën seisoen. Hulle reikwydte- en
terrein-groottes was uiteraardelik groot vir ‘n lae-digtheid areas, maar dit is nie
buitengewoon nie. Die mees betekenisvolle gevolgtrekking van die studie was die
voorkeur vir die Colophospermum mopane struikveld op kalkreet landskappe wat beskou
word as uniek aan Suid-Afrika, en wat ook beskou was as ‘vermy’ deur vroër KNP
studies tov. landskap voorkeure spesifiek vir renosters. Die grasbedekking in Pafuri,
alhoewel yl en baie droog, het tog oor ‘n verskeidenheid grasse beskik wat van lae tot
hoë weidings waarde het, en wat die renosters tot die beste van hulle vermoë benut
het. Die oorvloedige teenwoordigheid van beide spesies met matige weidingswaarde
in hulle dieët en die lae hoeveelheid van spesies met lae weidingswaarde, impliseer
dat hulle die geleentheid om op voedingsryke grasse te voed ten volle benut wanneer
dit beskikbaar is. Ons resultate dui daarop dat die Pafuri omgewing geskik is vir die
vestiging van ‘n klein teel-nukleus van wit renosters. Die oorvloedige
teenwoordigheid van permanente waterbronne in die vorm van fonteine is ‘n groot
voordeel, maar die kans vir bosindringing in hierdie grasveld-gebiede met lae reënval
moet oorweeg word sou die populasie aanhou toeneem teen die huidige tempo. Die
geboorte van twee nuwe kalfies in 2008 staaf die moontlikheid dat die renosters
gevestig en aangepas het in hulle nuwe habitat, wat ‘n baie belowende teken is vir die
toekoms van die groeiende subpopulasie.
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Soil nitrogen and phosphorus depletion as a means of restoring degraded lowland fynbos ecosystems invaded by alien grassesRuwanza, Sheunesu 03 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Much of South African lowland fynbos vegetation has been transformed by agriculture and invasive alien grass species. The artificial reduction of plant available N and P levels in soils, through the addition of carbon and calcium respectively, may provide a means of retarding the growth of alien grasses stimulated by soil nutrient enrichment. Furthermore, the competitive advantage of native lowland fynbos species adapted to nutrient impoverished soils may be increased by these additions.
The above premise was tested in both field- and greenhouse-based trials by applying systemic and contact herbicides to reduce the large alien invasive grass biomass. This was followed by the addition of C as sucrose and Ca as gypsum to reduce plant available N and P respectively in the soils. The effects of these combined herbicide and soil nutrient amendment treatments on plant physiology and growth were examined in both resident alien and indigenous species and in several herbaceous and woody native species introduced as seeds and seedlings. Also, soils sampled from the different treatments in both trials were chemically analyzed. There was a total absence of seedling recruitment from seeds of all 9 indigenous species sown into soils in the field-based trial while introduced juveniles of another 9 indigenous species displayed a high mortality during the dry summer season. These detrimental effects were less severe in the greenhouse-based trial which received more regular watering and where successful seedling recruitment from seeds sown occurred in four indigenous species. Sucrose additions, both exclusively and in combination with gypsum, caused significant reductions in foliar chlorophyll, photosystem II (PSII) function and above-ground biomass of most resident and introduced alien and indigenous species. These reductions were less prominent where herbicides were applied, a possible consequence of N and P supplementation of soils by the decomposing plant biomass. This was supported by the elevated soil K, Na and N concentrations measured in soils where contact and systemic herbicides were applied. However, no significant changes in soil N or P were apparent following sucrose and gypsum additions respectively, the latter attributed to the acidic soils which precluded the formation of insoluble P complexes.
A second study tested the hypothesis that exogenous sucrose addition to soils inhibits plant growth by stimulating soil microbial biomass which accumulates soil nitrogen rendering it unavailable to plants. Two native, early seral species (Dimorphotheca pluvialus (L.) Moench and Ursinia anthemoides (L) Poir. subsp anthemoides) were cultured in heat sterilized (2200C for 72 hours) and non-sterilized soils in a greenhouse under four different levels of sucrose (0, 100, 200 and 300 g m-2) supplied monthly over a four-month active growing period. Foliar chlorophyll
iii
contents, photosystem II (PSII) efficiencies, shoot and root lengths and dry mass, inflorescence numbers and N and P contents were measured in the plants, and N and P contents and bacterial cell and coliform numbers analyzed in the soils. Both D. pluvialis and U. anthemoides displayed significant reductions in PSII efficiency, chlorophyll content, accumulation of biomass and N and P in response increased levels of sucrose, which initially seemingly supported the hypothesis as these reductions were of substantially greater magnitude in plants cultivated in non-sterilized than sterilized soils. Despite this, there was no evidence of any significant increases in bacterial and coliform cell numbers in response to increased levels of sucrose supplied or any significant reductions in soil N and P contents following sucrose additions in both sterile and non-sterilized soils. Greater numbers of bacteria and coliforms were measured in sterilized than non-sterilized soils which corresponded with reduced soil N contents but these were not reflected in like changes in plant PSII efficiency and growth and total amounts of N taken up by plants which displayed massive increases in sterilized soils. The findings did not support the hypothesis and pointed to an abiotic mechanism of sucrose inhibition of plant photosynthesis and growth.
The study concludes that the suitability of adding sucrose and gypsum to degraded renosterveld ecosystem soils to promote the competitiveness of native taxa against alien grasses is dubious. Other restoration alternatives such as natural re-colonization, transfer of soils containing viable seeds from pristine communities and top soil removal should be considered. / AFRIKAANSE OPSOMMING: Baie van Suid Afrika se laagland fynbos plantegroei is verander deur landbou en uitheemse indringer grasspesies. Die kunsmatige reduksie van plantbeskikbare N en P vlakke in die grond deur die toevoeging van koolstof en kalsium onderskeidelik, kan ’n metode wees om die groei van indringer grasse te vertraag, wat gestimuleer word deur grondvoedingstofverryking. Die kompeterende voordeel van die inheemse laagland fynbosspesies wat aangepas is tot voedingstofarme grond kan verhoog word deur die toevoegings.
Bogenoemde postulaat is in beide die veld- en die glashuis-gebaseerde eksperimente getoets deur die aanwending van sistemiese en kontak onkruiddoder om die groot indringer grasbiomassa te verminder gevolg deur die byvoeging van C as sukrose en Ca as gips om die plantbeskibare N en P onderskeidelik te verminder in die grond. Die effekte van die gekombineerde onkruiddoder en grondvoedingstof verbeteringsbehandelings op die fisiologie en groei van die plante is ondersoek in beide inheemse- en residente indringerspesies asook in verskeie kruidagtige- en houtagtige inheemse spesies wat aangeplant was as sade en saailinge. Grondmonsters van die verskillende behandelings in beide studies was versamel en was chemies geanaliseer. Daar was ’n definitiewe afwesigheid van nuwe saailinge van sade van al nege indringerspesies wat gesaai was in grond in die veldgebaseerde studie, en saailinge van nog nege inheemse spesies het ’n hoë mortaliteit getoon gedurende die droë somerseisoen. Hierdie skadelike effekte was minder ernstig in die glashuisgebaseerde studie wat meer benat was, en waar nuwe saailinge suksesvol geproduseer was deur sade in vier inheemse spesies. Sukrose byvoegings, beide uitgesluit en in kombinasie met gips, het ’n afname in blaarchlorofil, fotosisteem II en bogrondse biomassa van die meeste van die residente en aangeplante indringer- en inheemse spesies getoon. Hierdie afnames was minder prominent waar onkruiddoder aangewend was, ’n moontlke oorsaak van N en P aanvulling van grond deur die verrottende plantbiomassa. Dit word ondersteun deur verghoogde grond K, Na en N konsentrasies, gemeet in grond waar kontak en sistemiese onkruiddoder toegevoeg was. Geen noemenswaardige veranderinge in grond N of P was sigbaar na byvoeging van sukrose en gips onderskeidelik nie. Laasgenoemde het bygedra tot suuragtige grond wat die formasie van onoplosbare P komplekse verkom het.
‘n Tweede studie het die hipotese getoets waar eksogene sukrose byvoeging tot grond plantegroei inhibeer deur die grond mikrobe biomassa te stimuleer wat akkumuleer wat in grond stikstof en dit nie beskikbaar maak vir plante nie.Twee inheemse vroeë intermediêre stadium spesies (Dimorphotheca pluvialus (L.) Moench en Ursinia anthemoides (L) Poir. subsp v
anthemoides) was gekweek in hitte gesteriliseerde grond (2200 C vir 72 uur) en in nie-gesteriliseerde grond in ’n glashuis onder vier verskillende vlakke van van sukrose (0, 100, 200 en 300 g m-2) bygevoeg maandeliks oor ‘n 4 maande aktiewe groei periode. Blaarchlorofilinhoud, fotosisteem II (FS II) doeltreffendheid, groeipunt en wortel lengte en droë massa, blomgetalle en N en P inhoud was gemeet in die plante sowel as N en P inhoud en bakteriële sel en kolivorm getalle was geanaliseer in die grond. Beide D. pluvialis en U . anthemoides het ’n afname getoon in FS II doeltreffendheid, chlorofilinhoud, biomassa akkumulasie, N en P response op verhoogde vlakke van sukrose, wat aanvanklik aangetoon het dat dit die hipotese ondersteun want hierdie afnames wat heelwat groter in plante wat gekweek was in ongesteriliseerde grond as in gesteriliseerde grond. Daar was geen toename in baketriële en kolivorm sel getalle in rssponse tot verhoogde vlakke van sukrose byvoegings of enige noemenswaardige in grond N en P inhoud na byvoeging van sukrose in beide steriele en nie-steriele grond nie. Groot getalle bakterieë en kolivorme was gemeet in gesteriliseerde grond as in ongesteriliseerde grond. Dit korrespondeer met verminderde grond N inhoud maar dit was nie gereflekteer in veranderinge in plant FS II doeltreffendheid, groei en die totale hoeveelhede N wat opgeneem was deur plante wat ’n massiewe toename getoon het ongesteriliseerde grond nie. Hierdie bevindings het nie die hipotese ondersteun nie en het gewys na ’n abiotiese meganisme van sukrose inhibisie van plant fotosintese en groei.
Die studie lei dus af dat die geskiktheid om sukrose en gips by te voeg tot gedegradeerde renosterveld ekosisteemgrond om kompetisie tussen inheemse plante en indringer grasse te promoveer, twyfelagtig is. Ander restorasie alternatiewe soos natuurlike herkolonisasie, oordrag van grond wat lewensvatbare sade bevat van onbeskadigde gemeenskappe en bogrond verwydering word oorweeg.
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Elephant movements and human-elephant conflict in a transfrontier conservation areaVon Gerhardt-Weber, Katharina E. M. 03 1900 (has links)
Thesis (MScConEcol)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In this thesis I explore how elephant movements are impacted by human activity within
the context of the proposed Kavango-Zambezi Transfrontier Conservation Area (KAZA
TFCA) in southern Africa. Being a wide-ranging species, the movements of elephants
could be an excellent indicator as to the success of TFCAs in supporting species
persistence in an anthropogenic matrix. Understanding which areas beyond protected area
boundaries are of heightened conservation importance can provide managers and
governments with insights for the management of the elephant population of KAZA
TFCA, and assist managers and governments in prioritising conservation efforts.
Satellite radio collar data were used to model long-range elephant movement within
KAZA TFCA. Movement was compared between land use types (protected and nonprotected
areas). Home ranges, core areas and seasonal ranges were calculated from
collar data. Core and non-core areas were tested for significant differences in distance to
settlements, rivers, protected area, AFRI and elevation as these spatial and ecological
variables are believed to play a role in elephant habitat selection. Short-range elephant
movements were examined in a heterogeneous, patchy landscape mosaic of settlements
and agricultural fields, remnant forest patches, and secondary forests which were
surrounded on three sides by protected areas. Elephant penetration of the anthropogenic
matrix through the use of pathways was explored through ground-based surveys, and the
impact of pathways use on human-elephant conflict calculated.
I found that elephant behavioural plasticity allows for their persistence in a spatially
heterogeneous landscape. Elephants, especially bulls, penetrated the landscape matrix
beyond protected area boundaries. Land use planning initiatives are needed to identify
and protect reachable core zones/stepping stones of quality habitat outside of protected
areas, particularly in riparian zones. Differing male and female ranging behaviour within
the landscape matrix may require separate land use management strategies: bulls travelled
at night in non-protected areas at speeds that were four times faster than in protected
areas, and made use of core zones necessary for species persistence in a fragmented
landscape. A habitat corridor in the Zambian West Zambezi Game Management Area
was identified.
I found that during short range movements in heterogeneous environments, elephants
made use of pathways. Pathways may facilitate penetration of the anthropogenic matrix
and optimize foraging strategies by connecting predictable resources, such as crop fields,
with landscape features such as preferred shelter/ resting areas, crossing points at roads
and preferred drinking spots. Pathways were found to be the only significant spatial
variable in crop-raiding. Elephants foraged randomly while in homogenous crop patches,
but when travelling through a heterogeneous environment (entering or leaving
agricultural locales), movement was directional and non-random.
Lastly I suggest that crop attractiveness may be enhanced by water availability. Results
indicated that at both the landscape and the regional scale, repeat elephant movements to
core zones and along elephant pathways provided landscape ecological variables that
need to be considered by conservation managers in land use planning. In addition,
research on spatial awareness and navigational capabilities with regards to pathway use by elephants should be encouraged, as this research topic has been largely unexplored in
the scientific literature. / AFRIKAANSE OPSOMMING: In hierdie tesis verken ek die moontlike impak van menslike aktiwiteite op olifant
beweging binne die beoogde Kavango-Zambezi Oorgrens Bewaringsarea (KAZA TFCA)
in suider-Afrika. Olifante is wydlopende spesies, en dus kan hul ruimtelike strekking ‘n
uitstekende indikator wees van die sukses van oorgrens bewaringsareas in terme van die
ondersteuning wat dié programme bied om spesies se volharding in ‘n antropogeniese
matriks te verseker. Besturrders en regerings kan insig verkry deur te besef watter areas
buiten die in beskermde gebiede, van verhoogde bewarings belang in KAZA TFCA is.
Hierdie insig verleen ook bystand aan bestuurders en regerings met die prioritisering van
bewarings inisiatiewe. Satelliet-radio nekband data was gebruik om olifante se
langtermyn ruimtelike beweging binne die KAZA TFCA te modelleer. Olifant beweging
was vergelyk tussen verskillende grondgebruik tipes (beskermde en onbeskermde areas).
Tuistestrekking, kern areas asook seisoenale strekking was bereken vanaf nekband data.
Kern en nie-kern areas was getoets vir betekenisvolle verskille in afstand vanaf
nedersettings, riviere, berskermde gebiede, AFRI, en hoogte bo seevlak, omdat hierdie
ruimtelike en ekologiese veranderlikes ‘n belangrike rol mag speel in olifant habitat
seleksie. Kortafstand olifant bewegings was bestudeer in ‘n heterogene, gelapte landskap
mosaïek van nedersettings en landbougrond, oorblywende woudareas, en sekondêre
woude waarvan drie sye grens aan bekermde areas. Olifant indringing binne die
antropogeniese matriks deur die gebruik van weë/toegangsweë was verken deur middel
van landgebaseerde opnames, waarvolgens die impak van olifante se gebruik van hierdie
paaie op mens-olifant konflik bereken kon word.
My bevindinge wys dat plastisiteit in olifant gedrag dra by tot hul voortbestaan in ‘n
ruimtelik heterogene landskap. Olifante, maar meer spesifiek olifantbulle, penetreer wel
die landskap matriks buite beskermde area grense. Grondgebruik beplannings inisiatiewe
word dus benodig om bereikbare kern areas van kwaliteit habitat buite beskermde areas te
identifiseer en te beskerm – veral in rivieroewer sones. Verskille in bul en koei ruimtelike
strekking gedrag binne die landskap matriks, mag afsonderlike bestuur stratgieë vereis:
bv. bulle beweeg vier keer vinniger in die aand in onbeskermde areas teenoor in
beskermde gebiede, daarby maak hulle ook gebruik van kern areas wat kardinaal is vir
die voortbestaan van spesies in gefragmenteerde landskappe. ‘n Habitat deurgang was
geïdentifiseer in die Zambiese Wes-Zambesie Wildbestuurarea. Die studie het gevind dat
olifante gedurende kortafstand bewegings in heterogene omgewings gebruik maak
toegangsweë. Toegangsweë mag penetrasie van die antropogeniese matriks fasiliteer, en
verleen ook dat olifant weidingstrategieë die optimum bereik deur voorspelbare
hulpbronne soos gewaslanderye te konnekteer met landskap eienskappe soos voorrang
skuiling/rusareas, kruisingspunte by paaie, asook voorrang drinkplekke. Toegangsweë
was gevind om die enigste betekenisvolle ruimtelike veranderlike in gewasstrooptogte te
wees. Olifante wei lukraak in homogene gewaslanderye, maar in teenstelling, wanneer
hulle deur ‘n heterogene omgewing beweeg het (binnegang of uittog uit landbou
lokaliteite) was die beweging gerig. Laastens, die studie stelvoor dat gewas aantreklikheid verhoog kan word deur water beskikbaarheid. Resultate dui aan dat by
beide die landskap- en streekskaal verskaf herhaalde olifant beweging na kern areas en
langs olifants togangsweë, landskap ekologiese veranderlikes wat in ag geneem moet
word deur bewaringsbestuurders tydens grondgebruik beplanning. Bykomend, navorsing
op die ruimtelike bewustheid en navigasie vermoëns van savannah olifante met
betrekking tot die gebruik van toegangsweë, moet aangemoedig word aangesien hierdie
onderwerp grootliks onverken is in wetenskaplike literatuur.
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Arthropods associated with commercial Proteaceae in the Western Cape Province, South AfricaSasa, Archbold 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The commercial cultivation of Proteaceae is an important industry in the Western Cape,
however, farmers are challenged with arthropod infestation which compels them to solely
rely on chemical pesticides. Past studies in South Africa have shown that Proteaceae
comprise a rich and diverse arthropod fauna. However, as most of these studies were
conducted on wild Proteaceae, they may not be representative of cultivated proteas.
Moreover, most of these species remained unidentified due to lack of identification expertise.
These past studies, however, form a useful baseline for arthropod studies in proteas, e.g. the
feeding guilds found in proteas. The aim of this research was to conduct an intensive and
extensive survey of the arthropod-fauna associated with commercially-cultivated proteas
across an entire year. Specifically, this survey was designed to document the composition of
the arthropod fauna (creating a comprehensive reference collection for pest management
purposes) and to assess whether the arthropod fauna differed between seasons and pesticide
treatments.
Infructescences, inflorescences and foliage of mainly commercial Proteaceae were sampled
for arthropods seasonally for a period of twelve months by collection of plant material and
direct searching. Seven commercial protea blocks, and a wild protea block (remnant patch of
fynbos vegetation), were used as the sampling sites, and two sprayed blocks were used for
assessing pesticide efficacy. Individual arthropods were identified as far as possible, with
37% identified to species level. A species accumulation curve showed that rare (minor)
arthropod species made up of 70% of arthropods occurring in cultivated proteas.
More than 8 700 individuals from more than 140 species and about 80 families were
collected and identified, revealing that cultivated proteas have a rich and diverse insect fauna.
These arthropods represent the full range of plant-feeding guilds: leaf miners, leaf chewers,
flower bud borers, sap suckers and seed feeders. Flower visitors/free living guild was the
most abundant (72%) and speciose (25%). In addition to phytophages, there was a large suite
of insect predators and parasitoids. A large number of the arthropods were endemic to the
Cape Floristic Region (CFR) and some (7.86%) have a pest status, in that they cause
significant damage to the protea plants (for example, 60% of Safari sunset cultivar
(Leucadendron salignum x L. laureolum) new flush stems and leaves were affected by
Epichoristodes acerbella (Tortricidae). Capys alphaeus (Lycaenidae) and Phyllocnistis sp.
(Phyllocnistidae) appear to be specialist pests, as they attack mainly Protea cynaroides and
Susara cultivar (Protea magnifica x P. susannae) respectively.
Arthropod abundance did not differ significantly between seasons, although significant
seasonal effects were observed in species richness when the protea cultivars were examined
separately. Pesticide application did not affect arthropod abundance, but did decrease species
richness in sprayed blocks. Pesticides appeared to negatively affect minor (rare) species
disproportionately, probably due to their lack of prior exposure to pesticides and hence
sensitivity. Due to this inefficacy of pesticides in cultivated proteas, an increasing emphasis
on the importance of non-chemical control measures, and our improved knowledge of the
predatory and parasitic species in this system, integrated pest management strategies deserve
greater research attention.
Monitoring and use of threshold values for arthropod pests were suggested here, as well as
the use of biological, cultural, physical and chemical (optimal use) control. For instance, in
cultural control, polycropping and intercropping in proteas to increase plant diversity in the
monocultures to promote a higher density of predators and parasitoids can be used. Certain
flowering plants are known to provide greater temporal and spatial distribution of nectar and
pollen sources, which can increase parasitoid reproductive potential and abundance of
alternative hosts/prey when the pest species are scarce or at an inappropriate stage. / AFRIKAANSE OPSOMMING: Die kommersiële verbouing van Proteaceae (proteas) is 'n belangrike bedryf in die Wes-Kaap.
Menige plantasie wemel egter van artropodes, wat boere noop om slegs van chemiese
plaagdoders gebruik te maak. Vorige studies in Suid-Afrika toon dat proteas die gasheerplant
vir 'n ryke en diverse artropodefauna is. Aangesien die meeste van hierdie studies egter op
wilde proteas uitgevoer is, weerspieël dit moontlik nie die stand van sake met verboude
proteas nie. Weens 'n gebrek aan kundigheid om die artropodes te eien word baie van die
spesies boonop nooit uitgeken nie. Dié studies voorsien egter 'n nuttige grondlyn vir 'n
ondersoek na die artropodes op proteas, veral vir die bestudering van die gilde wat van die
protea leef (“the feeding guild”). Hierdie navorsing het ten doel om 'n intensiewe en
omvattende opname te maak van die artropodefauna wat oor die tydperk van 'n jaar op
kommersieel verboude proteas voorkom. Die opname is meer bepaald ontwerp om die
samestelling van die artropodefauna te bestudeer (deur 'n omvattende verwysingsversameling
vir plaagbestuurdoeleindes te skep), en om vas te stel of seisoene en plaagbehandelings enige
beduidende uitwerking op die artropodefauna het.
Oor 'n tydperk van 12 maande is seisoenale monsters van die vrug- en bloeistadia, saadkoppe
en blare van hoofsaaklik kommersiële proteas gesoek en ingesamel. Sewe kommersiële
proteablokke sowel as 'n blok wilde proteas het as proefpersele gedien, en twee bespuite
blokke is gebruik om die doeltreffendheid van plaagdoder te beoordeel. Individuele
artropodes is so noukeurig moontlik uitgeken – 37% tot op spesievlak. Volgens 'n
spesieakkumulasiekurwe maak seldsame (kleiner) artropodespesies sowat 70% van die
artropodes uit wat op verboude proteas voorkom.
Die meer as 8 700 individue van meer as 140 spesies en sowat 80 families wat ingesamel en
uitgeken is, toon die rykheid en diversiteit van die artropodefauna op verboude proteas.
Hierdie artropodes verteenwoordig die volle reeks plantvreterspesies – van blaardelwers en
blaarkouers tot blomknopboorders, sapsuiers en saadvreters. Blombesoeker-/vrylewende
spesies was die volopste (72%) en mees divers (25%). Buiten plantvreters was daar ook 'n
groot aantal roofinsekte en parasitoïede. Baie van die artropodes was inheems, en sommige
(7,86%) het boonop plaagstatus, aangesien hulle beduidende skade aan die proteaplant aanrig.
[By ongeveer 60% van die Safari Sunset-kultivar (Leucadendron salignum x L. laureolum) is
nuwe stamme en blare byvoorbeeld deur die Epichoristodes acerbella (Tortricidae)
aangetas.] Capys alphaeus (Lycaenidae) en Phyllocnistis sp. (Phyllocnistidae) blyk
spesialisplae te wees wat onderskeidelik hoofsaaklik die Protea cynaroides en die Susarakultivar
(Protea magnifica x P. susannae) in die visier het.
Artropodegetalle het nie juis tussen seisoene gewissel nie, hoewel 'n afsonderlike ondersoek
van die proteakultivars 'n beduidende seisoenale uitwerking op spesierykheid aan die lig
gebring het. Eweneens het die toediening van plaagdoder nie die artropodegetalle verminder
nie, maar wel spesierykheid op die bespuite blokke verswak. Plaagdoders blyk besonder
negatiewe uitwerking op kleiner (seldsame) spesies te hê – waarskynlik omdat dié spesies nie
voorheen aan plaagdoders blootgestel was nie, en dus gevoelig is daarvoor. Weens die
oënskynlike ondoeltreffendheid van plaagdoders op verboude proteas, verg 'n toenemende
klem op die belang van niechemiese beheermaatreëls, 'n behoefte aan meer kennis van die
roof- en parasitiese spesies in die stelsel, en die vraag na geïntegreerde plaagbeheerstrategieë,
meer navorsing.
Die studie moniteer en gebruik drempelwaardes vir artropodeplae, sowel as biologiese,
kulturele, fisiese én chemiese (‘optimalegebruik’-) plaagbeheer. Met kulturele beheer kan
poli- en interverbouing van proteas byvoorbeeld gebruik word om plantdiversiteit in die
monokulture te verbeter, ten einde só 'n hoër digtheid van roofspesies en parasitoïede in die
hand te werk. Sekere blomplante bied kenmerkend 'n wyer tyd- en ruimtelike verspreiding
van nektar- en stuifmeelbronne, wat parasitoïede se voortplantingsvermoë en die getalle van
alternatiewe gashere/prooi kan verbeter wanneer die plaagspesies skaars is of in 'n
ontoepaslike stadium verkeer.
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