Five techniques were used to predict the potential biogeography of the four alien plant species, Acacia longifolia, Acacia mearnsii, Opuntia ficus-indica and Solanum sisymbrifolium. Prediction was based on five environmental factors, median annual rainfall, co-efficient of variation for rainfall, mean monthly maximum temperature for January, mean monthly minimum temperature for July and elevation. A geographical information system was used to manage the data and produce the predictive maps. The models were constructed with presence and absence data and then validated by means of an independent data set and chisquared tests. Of the five models used, three (the range, principal components analysis and discriminant function analysis) were linear while the other two (artificial neural networks and fuzzy logic) were non-linear. The two non-linear techniques were chosen as a plant's response to its environment is commonly assumed to be non-linear. However, these two techniques did not offer significant advantages over the linear methods. The principal components analysis was particularly useful in ascertaining the variables that were important in determining the distribution of each species. Artifacts on the predictive maps were also proved useful for this purpose. The techniques that produced the most statistically accurate validation results were the artificial neural networks (77% correct median prediction rate) and the discriminant function analysis (71% correct median prediction rate) while the techniques that performed the worst were the range and the fuzzy classification. The artificial neural network, discriminant function analysis and principal component analysis techniques all show great potential as predictive distribution models.

Torpedograss (Panicum repens) was first observed in Lake Okeechobee in the 1970s and appears to have displaced an estimated 6,400 ha of native plants, such as spikerush (Eleocharis cellulosa), where inundation depths are often less than 50 cm. Two series of studies evaluated substrate exposure and water depth influences on torpedograss establishment and competitiveness. Results revealed that fragments remain buoyant for extended periods and so facilitate dispersal. Once anchored to exposed substrate fragments can readily root and establish. Subsequently, torpedograss thrives when subjected to inundations to 75 cm and survives prolonged exposure to depths greater than 1 m. These findings suggest that fluctuating water levels contribute to torpedograss dispersal and colonization patterns and that low water levels increase marsh area susceptible to invasion. The competition study found that spikerush grown in monoculture produces significantly more biomass when continually inundated to shallow depths (10 to 20 cm) than when subjected to drier conditions (-25 cm) or greater inundations (80 cm). In contrast, torpedograss establishes more readily on exposed substrate (-25 to 0 cm) compared to inundate substrates. During the first growing season biomass production increases as substrate exposure interval increases. However, during the second year, established torpedograss produces more biomass when grown on intermittently wet (0 cm) compared to permanently dry (-25 cm) or intermittently inundated (10 cm) substrates. No difference in production was observed between substrates permanently inundated (10 cm) and any other regime tested. During the first two years of torpedograss invasion, regardless of treatment, spikerush suppresses invasion and torpedograss had little effect on established spikerush, indicating that spikerush-dominated areas are capable of resisting torpedograss invasion. Even so, disturbances that might cause mortality of long hydroperiod species, such as spikerush, may create open gaps in the native vegetation and thus facilitate torpedograss establishment and expansion.

MSc (Microbiology) / Department of Microbiology / See the attached abstract below.

Michaela Kubátová Alien species of plants and biotic resistence of invaded communities This study is about problems and questions of alien plants and their relation to native communities in their new range. Ecologists are increasingly aware that soil organisms may affect plant communities because they are part of the processes that affect them. The soil organisms may affect the success of alien species invasion. Each species of plants differ in interaction with soil organisms, these interactions can result in specific feedback that will influence the future growth of other plants. According to Darwin's naturalization hypothesis related species should have similar enemies. This implies less successful invasion of alien plants at home with relatives. The practical part consists of two experiments. Using plant-soil feedback I studied under controlled conditions the importance of kinship of native plants and their soil organisms on the growth of three species of alien plants Impatiens, Parviflora, Stenactis annua and Epilobium ciliatum. There were used soil samples from localities with related and unrelated species; the soil was used as inoculums for growing first-generation plants, where there were original related, unrelated and alien plants. In the second phase only alien species were grown. Part of...

MSc (Botany) / Department of Botany / Invasive alien plants (IAPs) are non-native species that have spread beyond the introduction site; become abundant to an extent that they serve as agents of change that also threaten native biological diversity (Garcia-Berthou, 2007). IAPs have medicinal applications for the treatment of various aliments in humans (Jäger et al., 1996). In this study, an ethnomedicinal survey was conducted on medicinal uses of invasive alien plant species in order to identify and investigate the various disease treatment methods employed by Bapedi traditional health practitioners within Capricorn District. Six traditional health practitioners were randomly selected, via the snowball method from each of the five local municipalities namely: Aganang, Blouberg, Lepelle-Nkupi, Molomole and Polokwane. The whole survey included 30 traditional health practitioners. A semi structured questionnaire was administered to document information about the medicinal uses of IAPs from participants. The collected data from the questionnaire was captured in Microsoft Excel 2010 and analyzed using descriptive statistics. The study recorded 22 IAPs belonging to 14 plant families. Records or data collected show invasive alien plants species to have been used for treatment of different alignments amongst Bapedi traditional health practitioners. Plant families with the most recorded species include: Solanaceae and Myrtaceae with 18.2% for both of them. The plant parts most frequently used in descending order were as follows: roots vii (40%), followed by the leaves (39%), fruits (7%), thorns (6%), bark (4%), seeds (2%) and lastly stems (2%). Decoction was recorded as the most dominant method used during medicinal preparations (n = 176) and flu was recorded as the most treated ailment amongst traditional health practitioners (n = 29). Apart from clearing IAPs as part of management strategy by South African government, there are other alternative innovative ways that can be employed to ensure that the number of IAPs introduced does not exceed beyond measure.This could be achieved by encouraging local people to use them as either medicinal sources or by incorporating them into any other local ethnobotanical use. The new innovative ways (such as traditional health practitioners utilizing the IAPs instead of endangered plants or indigenous plants species) can bring in some form of relief to the already declining indigenous species populations. Research scholars from different research institutes and higher education research centres can regard IAPs used medicinally as source of new pharmaceutical leads to create new medications. With such attention turned to alien invasive species, their survival as well as their spread will be kept on check at the same time creating a control measure to their spread with little effort. Further laboratory-based studies are needed to determine efficiency and safety of the IAPs used by traditional health practitioners in this study. / NRF

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The spatial distribution of animals and plants at different scales is a central theme in ecology. Knowledge of biodiversity distribution is essential, especially with the current threat of climate change and invasion by alien species. Since the impact of climate change and alien species will be, and has already been pronounced in polar regions, information on the current spatial distributions of biota in these regions is critical to predict the consequences of climate change and alien species on the future survival, distribution and abundance of indigenous biota. This study was conducted on the sub- Antarctic Prince Edward Islands (consisting of Marion Island and Prince Edward Island), which have experienced rapid climate changes over the past 50 years. Additionally, a number of alien plant, vertebrate and invertebrate (also microarthropod) species have been introduced to these islands. Since microarthropods (mites and springtails) play an essential role in decomposition and mineralization of plant material on the islands, the loss of microarthropods from decomposer communities might have disastrous results for ecosystem processes. Therefore it is essential to know the current distributions of microarthropods in order to predict future distributions patterns in reaction to climate change and invasive species. In this study, the spatial distribution of mites and springtails inhabiting the cushion plant Azorella selago Hook, were examined at different scales of observation. Firstly, the microarthropod community was examined at a fine scale. The relationship between microarthropod species richness and abundance and plant size, isolation, within-plant variability, grass cover and microclimate variables were investigated. Thereafter, the spatial variability of microarthropod abundances was examined within stands of plants, with statistical methods using varying degrees of locational information to determine if microarthropod abundance is random, regular or aggregated at this scale. Further, the spatial variability of microarthropod communities in A. selago at different altitudes and on different sides of Marion Island, i.e. island-wide scale, was examined. The last scale of observation was the island-wide scale, in which microarthropod assemblages were compared between Marion Island and Prince Edward Island, as well as in different plant species. Microarthropods showed spatial heterogeneity within A. selago plants (higher abundances in eastern and southern sides of plants), island-wide (lower springtail abundance on the eastern side of the island and at high altitudes) and between islands (more alien species on Marion Island). In contrast, microarthropod abundance was not spatially heterogeneous within a stand of plants, i.e. mostly randomly distributed. The possible mechanisms responsible for these patterns differ between scales, and range from temperature and nutrient availability at the within plant and island wide scale to alien species between islands. Climate change is likely to alter these distribution patterns of microarthropods, either directly (unfavourable climate for indigenous species growth, development and dispersal) or indirectly (favouring alien microarthropod species; increase in grass cover on A. selago plants may alter community structure). The information presented here, is essential for predicting the possible impacts of climate change on microarthropods in fellfield ecosystems on sub-Antarctic islands. / AFRIKAANSE OPSOMMING: Die ruimtelike verspreiding van diere en plante op verskillende skale is ‘n sentrale tema in ekologie. Kennis van die verspreiding van biodiversiteit is belangrik, veral met die huidige bedreiging van klimaatsverandering en indringerspesies. Omdat die impak van klimaatsverandering en indringerspesies in die poolstreke alreeds duidelik is en nog meer so sal word, is inligting oor die huidige ruimtelike verspreiding van biota in hierdie streke noodsaaklik. Hierdie studie is op die sub-Antarktiese Prins Edward-eilande (bestaande uit Marion Eiland en Prins Edward Eiland) uitgevoer, waar die klimaat vinnig verander het oor die afeglope 50 jaar. Bykomend is ‘n aantal indringer plant, vertebraat en invertebraat (ook mikroartropood) spesies op die eilande ingebring. Omdat mikroartropoda (myte en springsterte) ‘n baie belangrike rol in ontbinding en mineralisering van plantmateriaal op hierdie eilande speel, sal die verlies van mikroartropoda uit die ontbindingsgemeenskap rampspoedige gevolge vir die prosesse in die ekosisteem hê. Kennis van die huidige verpreiding van mikroartropoda is dus noodsaaklik om die toekomstige verspreidingspatrone, asook oorlewing en volopheid van inheemse spesies in reaksie op klimaatsveranding en indringerspesies, te voorspel. In hierdie studie is die ruimtelike verspreiding van myte en springsterte wat in die kussingplant Azorella selago Hook voorkom, op verskillende ruimtelike skale ondersoek. Eerstens is die mikroartropood gemeenskap op ‘n klein skaal ondersoek. Die verwantskap tussen mikroartropood spesies rykheid en volopheid en plantgrootte, isolasie, binne-plant variasie, gras bedekking en mikroklimaat faktore is ondersoek. Daarna is die ruimtelike variasie van mikroartropood volopheid binne in ‘n plantstand ondersoek deur gebruik te maak van metodes wat verskillende grade van ligging data gebruik. Dit is gedoen om uit te vind of mikroartropood volopheid lukraak, reëlmatig of versameld verspreid is. Verder is die ruimtelike verspreiding van mikroartropood gemeenskappe in A. selago op verskillende hoogtes bo seespieël en op verskillende kante van Marion Eiland ondersoek. Laastens is die mikroartropood gemeenskap op Marion Eiland en Prins Edward Eiland, asook die gemeenskap in verskillende plant spesies vergelyk. Mikroartropoda is ruimtelik heterogeen verspreid binne-in A. selago (meer individue in die oostelike en suidelike kante van plante), asook regoor Marion Eiland (minder springstert individue aan die ooste kant van die eiland asook minder op hoë hoogtes bo seespieël) en tussen eilande (meer indringerspesies op Marion Eiland). In teenstelling hiermee is mikroartropood volopheid ruimtelik homogeen oor ‘n plantstand, dus meestal lukraak verspreid. Die meganismes wat moontlik vir hierdie patrone verantwoordelik is wissel van temperatuur en voedselbeskikbaarheid op die binne-plant en oor die eiland skaal tot indringerspesies op die tussen-eiland skaal. Klimaatsverandering mag waarskynlik mikroartropood verspreidingspatrone direk (ongunstige klimaat vir inheemse spesies se groei, ontwikkeling en verspreiding), of indirek verander (indringer spesies word begunstig; toename in grasbedekking bo-op A. selago mag die gemeenskapstruktuur van mikroartropoda verander). Hierdie inligting is belangrik vir die voorspelling van die moontlike impak van klimaatsverandering op mikroartropoda in klipveld ekosisteme op sub-Antarktiese eilande.

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: With only 1.76% conserved West Coast Renosterveld remaining it is crucial to prioritize the conservation and management of this fragile vegetation type. Because of its occurrence on fertile soils, renosterveld has been cleared for cultivation and other agricultural use and is thus fragmented to a critical point. These remaining fragments are subject to extensive edge effects and the exact parameters of a viable fragment must still be determined. The extent of alien grass species invasion into remnant renosterveld patches was determined using data collected using the line-intercept method. Sampling included three different management treatment areas adjacent to old lands: 1) a recently burned area, 2) a grazed area and 3) an unburnedlungrazed area providing a control sample. Additionally all small-scale soil disturbances along the lines were recorded. Results showed that Briza spp., Bromus spp. and Avena fatua were the most significant invading alien grass species. There was a significantly high variation between alien grass cover in each treatment, with the grazed area containing the highest overal! level of alien grass invasion. The control area, with the exclusion of fire and animal activity, showed minimum alien grass invasion. Edge effects were apparent in all treatments, but were lowest in the control area, where percentage alien grass cover significantly decreased after a distance of fifteen meters into the remnant patch. A weak positive correlation between the occurrence of alien grass and indigenous grass was found, as well as evidence of a weak association between alien grass cover and shrub cover. The possibility that small-scale soil disturbances could be an important contributing factor to alien grass invasion was supported by the positive correlation between disturbances and percentage alien grass cover. A positive correlation was found between the occurrence of indigenous grass and small-scale soil disturbances, while shrub cover tended to be less associated with animal activity. It is concluded that the correct management regime could effectively control the excessive invasion of alien grass species into the remnant renosterveld patches. Grazing (including all animal activity and small-scale soil disturbances) was the main facilitator of alien grass establishment - even dominating the prominent consequences of edge effects by facilitating alien grass establishment much deeper into the remnant patches. It could be assumed that a precise balance of low-pressure grazing and fire management should be established to enable the effective control of alien grass species while maintaining optimum biodiversity. Keywords: renosterveld, alien grass, grazing, fire, management, small-scale soil disturbances / AFRIKAANSE OPSOMMING: Met slegs 1.76% oorblywende Weskus Renosterveld wat bewaar word, is die beskerming en effektiewe bestuur van hierdie bedreigde plantegroei 'n prioriteit. Die vrugbare grond waarop renosterveld voorkom, het veroorsaak dat dit uitgeroei word om eerder die kultivering van ekonomies produktiewe landbou gewasse moontlik te maak. Dus het renosterveld verminder en gefragmenteer tot 'n kritieke punt. Hierdie ooblywende klein areas bedek met renosterveld, is blootgestel aan ekstensiewe invloede van die omliggende areas en die presiese afmetings vir 'n effektiewe grate renosterveld fragment vir bewarings doeleindes, moel nog vasgestel word. Die male van uitheemse gras spesie indringing in hierdie renosterveld fragmente is ondersoek deur die versameling van data deur die lyn-onderskep metode. Drie verskillende bestuursstelsels vir renosterveld is ondersoek om vas te stel wat die ergste graad van uitheemse gras indringing voorkom. Die studie het 'n 1) onlangs gebrande area, 2) 'n beweide area en 3) 'n kontrole area (wat nie gebrand of bewei is nie) ondersoek. Alle kleinskaalse grond-versteurings langs die lyne is ook aangeteken. Die resultate het aangetoon dat Briza spp., Bromus spp. en Avena fatua, as uitheemse grasse, die belangrikste indringers was en dus die grootste bedreiging inhou. Daar was 'n beduidende hoë variasie tussen die mate van uitheemse gras bedekking aangeteken in elk van die bestuurs-stelsels. Die beweide area het die hoogste graad van uitheemse gras indringing getoon, terwyl die kontrole area (in die afwesigheid van vuur en weidings aktiwiteite) die meeste weerstand teen uitheemse gras indringing getoon het. Die invloed van die omliggende omgewing was ook duidelik sigbaar in al drie die bestuurs-stelsels, maar was duidelik minder in die kontrole area waar die persentasie uitheemse gras indringing aansienlik verminder het na 'n afstand van vyftien meter in die renosterveld fragment in. 'n Swak positiewe korrelasie tussen die voorkoms van uitheemse grasse en inheemse gras spesies was aangeteken, asook bewyse van 'n swak negatiewe assosiasie tussen die uitheemse gras spesies en die inheemse bosse. Soos verwag, is daar bewyse gevind vir die teorie dat kleinskaalse grond-versteurings 'n belangrike fasiliterende faktor is vir uitheemse gras vestiging. Daar was 'n duidelike positiewe korrelasie tussen hierdie grond-versteurings en die persentasie uitheemse gras grondbedekking. Dieselfde positiewe assosiasie was gevind tussen die inheemse gras en hierdie kleinskaalse grond-versteurings, terwyl die inheemse bossie duidelik minder verbind was met die verskynsel. Die gevolgtrekking is gemaak dat 'n korrekte bestuurs-plan die indringing van uitheemse grasse effektief sal kan beheer. Dier aktiwiteite (insluitende beweiding, grawe van gate, mier en termiet neste ens.), en dus kleinskaalse grond-versteurings. was die grootste fasiliteerders van uitheemse gras indringing en vestiging binne hierdie renosterveld stukke. Dit oorheers selfs die aansienlike effek wat invloede van die omringende omgewing op hierdie areas het, deur die uitheemse gras indringing selfs dieper in die fragmente in aan te help. Daar kan dus aangeneem word dat 'n presiese balans tussen lae-intensiteit beweiding (en dus fauna aktiwiteit) en veld brande vasgestel moet word vir die effektiewe beheer van uitheemse gras spesies terwyl die optimum bio-diversiteit terselfde tyd gehandhaafword. Sleutelwoorde: renosterveld, uitheemse grasse, beweiding, vuur, veldbestuur, kleinskaalse grond-versteurings

The invasion of ecosystems by alien species is a growing threat to the delivery of ecosystem services. This study explored the spatial distribution of water hyacinth in the Benoni Lakes and made analysis of its impact on water availability and usability in order to understand the evolution and its propagation rates. The study used satellite imagery for lake level modelling using Remote Sensing and Geographical Information Systems for calculations of area covered by weeds in each lake from 2002 to 2012.The modelling approach illustrates the potential usefulness in projecting invasive plants under climate change and enabled the quantification of long term changes in aquatic weeds. The results showed that aquatic infestations in lakes may be used as powerful predictors of correlations between plant abundance and climate change. The study therefore informs decision makers to identify areas where invasion is likely to occur and increase surveillance for early invaders. / Environmental Sciences / M. Sc. (Environmental Management)

<p>Имајући&nbsp; у&nbsp; виду&nbsp; значај&nbsp; површинских&nbsp; вода&nbsp; у продору&nbsp; и&nbsp; ширењу&nbsp; страних&nbsp; инвазивних врста,&nbsp; циљеви&nbsp; овог&nbsp; рада&nbsp; били&nbsp; су&nbsp; да&nbsp; се представи&nbsp; актуелно&nbsp; стање&nbsp; присуства&nbsp; и дистрибуције&nbsp; акватичних&nbsp; инвазивних биљних&nbsp; врста&nbsp; у&nbsp; површинским&nbsp; копненим водама,&nbsp; анализира&nbsp; степен&nbsp; инвазије рипаријалних&nbsp; зона&nbsp; на&nbsp; подручју&nbsp; Србије, одреди&nbsp; везаност&nbsp; анализираних&nbsp; инвазивних<br />врста&nbsp; за&nbsp; поједине&nbsp; типове&nbsp; станишта&nbsp; у рипаријалу река и канала и анализира утицај различитих&nbsp; станишних&nbsp; и&nbsp; антропогених фактора&nbsp; на&nbsp; присуство&nbsp; и&nbsp; абунданцу&nbsp; 26 одабраних&nbsp; инвазивних&nbsp; таксона.&nbsp; Теренска истраживања&nbsp; вршена&nbsp; су&nbsp; у&nbsp; периоду&nbsp; од&nbsp; 2013. до&nbsp; 2016.&nbsp; године.&nbsp; За&nbsp; потребе&nbsp; овог&nbsp; рада анализирано је 250 локалитета, од чега 217 у рипаријалу&nbsp; 39&nbsp; река&nbsp; и&nbsp; 33&nbsp; у&nbsp; рипаријалу&nbsp; шест<br />деоница&nbsp; канала&nbsp; хидросистема&nbsp; Дунав-Тиса-Дунав.&nbsp; Уз&nbsp; податке&nbsp; о&nbsp; бројности&nbsp; и<br />покровности&nbsp; заступљених&nbsp; биљних&nbsp; врста, сакупљани&nbsp; су&nbsp; и&nbsp; подаци&nbsp; о&nbsp; типу&nbsp; станишта&nbsp; (у складу&nbsp; са&nbsp; EUNIS&nbsp; класификацијом), релевантним&nbsp; физичким&nbsp; и<br />хидроморфолошким&nbsp; карактеристикама истраживаних&nbsp; водотокова&nbsp; и&nbsp; доминантним антропогеним&nbsp; утицајима&nbsp; на&nbsp; истраживаном локалитету&nbsp; (у&nbsp; складу&nbsp; са&nbsp; стандардним протоколом&nbsp; RHS&nbsp; методе).&nbsp; Статистичка обрада&nbsp; података&nbsp; вршена&nbsp; је&nbsp; у&nbsp; софтверу CANOCO&nbsp; 5.0,&nbsp; применом&nbsp; анализе&nbsp; главних компоненти&nbsp; (РСА),&nbsp; канонијскe коресподентнe&nbsp; анализе&nbsp; (CCA)&nbsp; и&nbsp; анализе редундантности&nbsp; (RDA).&nbsp; На&nbsp; територији Србије&nbsp; забележено&nbsp; је&nbsp; присуство&nbsp; осам акватичних&nbsp; инвазивних&nbsp; биљних&nbsp; врстаПрема&nbsp; броју&nbsp; налаза&nbsp; истичу&nbsp; се&nbsp; врсте Vallisneria spiralis, Azolla filiculoides и Elodea&nbsp; nuttallii.&nbsp; Примарно су заступљене у текућим,<br />у односу на стајаће воде, при чему се мрежа&nbsp; канала&nbsp; ХС&nbsp; ДТД&nbsp; и&nbsp; речни&nbsp; токови&nbsp; који&nbsp; припадају&nbsp; сливу&nbsp; Дунава&nbsp; могу&nbsp; сматрати&nbsp; основним&nbsp; акватичним&nbsp; коридорима&nbsp; њиховог&nbsp; ширења.&nbsp; Од&nbsp; 26&nbsp; таксона&nbsp; инвазивних&nbsp; биљака&nbsp; чије&nbsp; је&nbsp; присуство&nbsp; праћено&nbsp; и&nbsp; анализирано&nbsp; у&nbsp; рипаријалним&nbsp; подручјима,&nbsp; таксони&nbsp; са<br />највећим&nbsp; бројем&nbsp; налаза&nbsp; су&nbsp;<em> Xanthium&nbsp; strumarium</em>&nbsp; subsp.&nbsp; <em>italicum,&nbsp; Amorpha</em> <em>fruticosa, Erigeron&nbsp; canadensis,&nbsp; Robinia&nbsp; pseudoacacia&nbsp; и&nbsp; Echinochloa&nbsp; crus-galli.</em>&nbsp; Речни&nbsp; сливови Дунава,&nbsp; Јужне&nbsp; Мораве,&nbsp; Западне&nbsp; Мораве&nbsp; и&nbsp; Тимока&nbsp; истичу&nbsp; се&nbsp; по&nbsp; заступљености&nbsp; истраживаних таксона. На основу података о дистрибуцији,&nbsp; бројности&nbsp; и&nbsp; покровности&nbsp; анализираних&nbsp; таксона&nbsp; сливови&nbsp; Дунава, Колубаре и Западне Мораве издвојили су се&nbsp; као&nbsp; коридори&nbsp; ширења&nbsp; највећег&nbsp; броја<br />истраживаних&nbsp; таксона.&nbsp; Четири&nbsp; типа&nbsp; станишта&nbsp; издвојила&nbsp; су&nbsp; се&nbsp; према<br />заступљености&nbsp; инвазивних&nbsp; биљних&nbsp; врста.&nbsp; Таксони који су забележени у највећем броју&nbsp; типова&nbsp; станишта&nbsp; су:&nbsp; <em>Amorpha&nbsp; fruticosa, Erigeron&nbsp; canadensis,&nbsp;</em> <em>Robinia&nbsp; pseudoacacia, Echinochloa crus-galli&nbsp;</em> и&nbsp; <em>Xanthium strumarium subsp</em>.&nbsp; <em>italicum.</em>&nbsp; Као&nbsp; резултат&nbsp; нумеричких&nbsp; анализа&nbsp; издвојени&nbsp; су&nbsp; физички&nbsp; и<br />хидроморфолошки параметри истраживаних&nbsp; водотокова&nbsp; и&nbsp; доминантни&nbsp; антропогени&nbsp; утицаји који на истраживаном локалитетима утичу&nbsp; на&nbsp; присуство&nbsp; и&nbsp; абунданцу&nbsp; анализираних&nbsp; таксона.&nbsp; У&nbsp; условима&nbsp; глобалних&nbsp; климатских&nbsp; промена&nbsp; може&nbsp; се&nbsp; очекивати да ће се&nbsp; у наредном периоду под снажним&nbsp; притиском&nbsp; ширења&nbsp; и&nbsp; доминације&nbsp; инвазивних врста наћи сливови Саве, Велике Мораве&nbsp; и&nbsp; Јужне&nbsp; Мораве.&nbsp; У&nbsp; рипаријалним областима на југозападу наше земље (долине Лима,&nbsp; Ибра&nbsp; и&nbsp; њихових&nbsp; притока)&nbsp; као&nbsp; и&nbsp; рипаријалним&nbsp; зонама&nbsp; планинских&nbsp; и високопланинских&nbsp; области&nbsp; такође&nbsp; је очекивано&nbsp; да&nbsp; ће&nbsp; доћи&nbsp; до&nbsp; повећања&nbsp; броја присутних&nbsp; инвазивних&nbsp; врста&nbsp; и&nbsp; њиховог даљег ширења.</p> / <p>Imajući&nbsp; u&nbsp; vidu&nbsp; značaj&nbsp; površinskih&nbsp; voda&nbsp; u prodoru&nbsp; i&nbsp; širenju&nbsp; stranih&nbsp; invazivnih vrsta,&nbsp; ciljevi&nbsp; ovog&nbsp; rada&nbsp; bili&nbsp; su&nbsp; da&nbsp; se predstavi&nbsp; aktuelno&nbsp; stanje&nbsp; prisustva&nbsp; i distribucije&nbsp; akvatičnih&nbsp; invazivnih biljnih&nbsp; vrsta&nbsp; u&nbsp; površinskim&nbsp; kopnenim vodama,&nbsp; analizira&nbsp; stepen&nbsp; invazije riparijalnih&nbsp; zona&nbsp; na&nbsp; području&nbsp; Srbije, odredi&nbsp; vezanost&nbsp; analiziranih&nbsp; invazivnih<br />vrsta&nbsp; za&nbsp; pojedine&nbsp; tipove&nbsp; staništa&nbsp; u riparijalu reka i kanala i analizira uticaj različitih&nbsp; stanišnih&nbsp; i&nbsp; antropogenih faktora&nbsp; na&nbsp; prisustvo&nbsp; i&nbsp; abundancu&nbsp; 26 odabranih&nbsp; invazivnih&nbsp; taksona.&nbsp; Terenska istraživanja&nbsp; vršena&nbsp; su&nbsp; u&nbsp; periodu&nbsp; od&nbsp; 2013. do&nbsp; 2016.&nbsp; godine.&nbsp; Za&nbsp; potrebe&nbsp; ovog&nbsp; rada analizirano je 250 lokaliteta, od čega 217 u riparijalu&nbsp; 39&nbsp; reka&nbsp; i&nbsp; 33&nbsp; u&nbsp; riparijalu&nbsp; šest<br />deonica&nbsp; kanala&nbsp; hidrosistema&nbsp; Dunav-Tisa-Dunav.&nbsp; Uz&nbsp; podatke&nbsp; o&nbsp; brojnosti&nbsp; i<br />pokrovnosti&nbsp; zastupljenih&nbsp; biljnih&nbsp; vrsta, sakupljani&nbsp; su&nbsp; i&nbsp; podaci&nbsp; o&nbsp; tipu&nbsp; staništa&nbsp; (u skladu&nbsp; sa&nbsp; EUNIS&nbsp; klasifikacijom), relevantnim&nbsp; fizičkim&nbsp; i<br />hidromorfološkim&nbsp; karakteristikama istraživanih&nbsp; vodotokova&nbsp; i&nbsp; dominantnim antropogenim&nbsp; uticajima&nbsp; na&nbsp; istraživanom lokalitetu&nbsp; (u&nbsp; skladu&nbsp; sa&nbsp; standardnim protokolom&nbsp; RHS&nbsp; metode).&nbsp; Statistička obrada&nbsp; podataka&nbsp; vršena&nbsp; je&nbsp; u&nbsp; softveru CANOCO&nbsp; 5.0,&nbsp; primenom&nbsp; analize&nbsp; glavnih komponenti&nbsp; (RSA),&nbsp; kanonijske korespodentne&nbsp; analize&nbsp; (CCA)&nbsp; i&nbsp; analize redundantnosti&nbsp; (RDA).&nbsp; Na&nbsp; teritoriji Srbije&nbsp; zabeleženo&nbsp; je&nbsp; prisustvo&nbsp; osam akvatičnih&nbsp; invazivnih&nbsp; biljnih&nbsp; vrstaPrema&nbsp; broju&nbsp; nalaza&nbsp; ističu&nbsp; se&nbsp; vrste Vallisneria spiralis, Azolla filiculoides i Elodea&nbsp; nuttallii.&nbsp; Primarno su zastupljene u tekućim,<br />u odnosu na stajaće vode, pri čemu se mreža&nbsp; kanala&nbsp; HS&nbsp; DTD&nbsp; i&nbsp; rečni&nbsp; tokovi&nbsp; koji&nbsp; pripadaju&nbsp; slivu&nbsp; Dunava&nbsp; mogu&nbsp; smatrati&nbsp; osnovnim&nbsp; akvatičnim&nbsp; koridorima&nbsp; njihovog&nbsp; širenja.&nbsp; Od&nbsp; 26&nbsp; taksona&nbsp; invazivnih&nbsp; biljaka&nbsp; čije&nbsp; je&nbsp; prisustvo&nbsp; praćeno&nbsp; i&nbsp; analizirano&nbsp; u&nbsp; riparijalnim&nbsp; područjima,&nbsp; taksoni&nbsp; sa<br />najvećim&nbsp; brojem&nbsp; nalaza&nbsp; su&nbsp;<em> Xanthium&nbsp; strumarium</em>&nbsp; subsp.&nbsp; <em>italicum,&nbsp; Amorpha</em> <em>fruticosa, Erigeron&nbsp; canadensis,&nbsp; Robinia&nbsp; pseudoacacia&nbsp; i&nbsp; Echinochloa&nbsp; crus-galli.</em>&nbsp; Rečni&nbsp; slivovi Dunava,&nbsp; Južne&nbsp; Morave,&nbsp; Zapadne&nbsp; Morave&nbsp; i&nbsp; Timoka&nbsp; ističu&nbsp; se&nbsp; po&nbsp; zastupljenosti&nbsp; istraživanih taksona. Na osnovu podataka o distribuciji,&nbsp; brojnosti&nbsp; i&nbsp; pokrovnosti&nbsp; analiziranih&nbsp; taksona&nbsp; slivovi&nbsp; Dunava, Kolubare i Zapadne Morave izdvojili su se&nbsp; kao&nbsp; koridori&nbsp; širenja&nbsp; najvećeg&nbsp; broja<br />istraživanih&nbsp; taksona.&nbsp; Četiri&nbsp; tipa&nbsp; staništa&nbsp; izdvojila&nbsp; su&nbsp; se&nbsp; prema<br />zastupljenosti&nbsp; invazivnih&nbsp; biljnih&nbsp; vrsta.&nbsp; Taksoni koji su zabeleženi u najvećem broju&nbsp; tipova&nbsp; staništa&nbsp; su:&nbsp; <em>Amorpha&nbsp; fruticosa, Erigeron&nbsp; canadensis,&nbsp;</em> <em>Robinia&nbsp; pseudoacacia, Echinochloa crus-galli&nbsp;</em> i&nbsp; <em>Xanthium strumarium subsp</em>.&nbsp; <em>italicum.</em>&nbsp; Kao&nbsp; rezultat&nbsp; numeričkih&nbsp; analiza&nbsp; izdvojeni&nbsp; su&nbsp; fizički&nbsp; i<br />hidromorfološki parametri istraživanih&nbsp; vodotokova&nbsp; i&nbsp; dominantni&nbsp; antropogeni&nbsp; uticaji koji na istraživanom lokalitetima utiču&nbsp; na&nbsp; prisustvo&nbsp; i&nbsp; abundancu&nbsp; analiziranih&nbsp; taksona.&nbsp; U&nbsp; uslovima&nbsp; globalnih&nbsp; klimatskih&nbsp; promena&nbsp; može&nbsp; se&nbsp; očekivati da će se&nbsp; u narednom periodu pod snažnim&nbsp; pritiskom&nbsp; širenja&nbsp; i&nbsp; dominacije&nbsp; invazivnih vrsta naći slivovi Save, Velike Morave&nbsp; i&nbsp; Južne&nbsp; Morave.&nbsp; U&nbsp; riparijalnim oblastima na jugozapadu naše zemlje (doline Lima,&nbsp; Ibra&nbsp; i&nbsp; njihovih&nbsp; pritoka)&nbsp; kao&nbsp; i&nbsp; riparijalnim&nbsp; zonama&nbsp; planinskih&nbsp; i visokoplaninskih&nbsp; oblasti&nbsp; takođe&nbsp; je očekivano&nbsp; da&nbsp; će&nbsp; doći&nbsp; do&nbsp; povećanja&nbsp; broja prisutnih&nbsp; invazivnih&nbsp; vrsta&nbsp; i&nbsp; njihovog daljeg širenja.</p> / <p>Bearing&nbsp; in&nbsp; mind&nbsp; the&nbsp; significance&nbsp; of&nbsp; inland surface waters for the introduction and spread of invasive&nbsp; alien&nbsp; species&nbsp; (IAS),&nbsp; the&nbsp; aims&nbsp; of&nbsp; this research&nbsp; were&nbsp; to&nbsp; present&nbsp; the&nbsp; contemporary records&nbsp; of&nbsp; aquatic&nbsp; invasive&nbsp; plant&nbsp; species&nbsp; in surface&nbsp; waters,&nbsp; analyse&nbsp; the&nbsp; level&nbsp; of&nbsp; invasion&nbsp; of riparian&nbsp; areas&nbsp; in&nbsp; Serbia,&nbsp; determine&nbsp; the&nbsp; habitat preferences&nbsp; of&nbsp; the&nbsp; analysed&nbsp; IAS&nbsp; and&nbsp; determine the effects of different habitat characteristics and anthropogenic&nbsp; influences&nbsp; on&nbsp; the&nbsp; presence&nbsp; and bundance&nbsp; of&nbsp; the&nbsp; 26&nbsp; analysed&nbsp; invasive&nbsp; plants. Field&nbsp; research&nbsp; was&nbsp; conducted&nbsp; during&nbsp; the&nbsp; 2013-2016&nbsp; period.&nbsp; A&nbsp; total&nbsp; of&nbsp; 250&nbsp; field&nbsp; sites&nbsp; were analysed&nbsp; as&nbsp; part&nbsp; of&nbsp; this&nbsp; research,&nbsp; 217&nbsp; in&nbsp; the riparian zones of 39 rivers and 33 in the riparian zones&nbsp;&nbsp;&nbsp; of&nbsp; six&nbsp; canal&nbsp; sections&nbsp; of&nbsp; the&nbsp; hydrosystem Danube-Tisa-Danube&nbsp; (HS&nbsp; DTD).&nbsp; In&nbsp; addition&nbsp; to data on the cover and abundance of the analysed plant species, data on habitat type (following the EUNIS&nbsp; classification),&nbsp; relevant&nbsp; physical&nbsp; and hydromorhological&nbsp; parameters&nbsp; of&nbsp; the&nbsp; studied watercourses&nbsp; and&nbsp; dominant&nbsp; anthropogenic influences an analysed field sites were recorded (following&nbsp; the&nbsp; standard&nbsp; RHS&nbsp; protocol). Statistical&nbsp; data&nbsp; analysis&nbsp; was&nbsp; done&nbsp; in&nbsp; CANOCO 5.0&nbsp;&nbsp; software,&nbsp; using&nbsp; the&nbsp; principal&nbsp; component analysis&nbsp; (PCA),&nbsp; canonical&nbsp; correspondence analysis (CCA) and redundancy analysis (RDA). Eight&nbsp; aquatic&nbsp; invasive&nbsp; plant&nbsp; species&nbsp; were recorded for the territory of Serbia. Species with the highest number of records were:&nbsp; Vallisneria spiralis,&nbsp; Azolla filiculoides&nbsp; and&nbsp; Elodea nuttallii. They&nbsp; are&nbsp; primarily&nbsp; present&nbsp; in&nbsp; running,&nbsp; in comparison&nbsp; with&nbsp; standing&nbsp; waters,&nbsp; and&nbsp; the&nbsp; canal network&nbsp; of&nbsp; the&nbsp; HS&nbsp; DTD&nbsp; and&nbsp; rivers&nbsp; of&nbsp; the Danube catchment area are considered to be their main&nbsp; aquatic&nbsp; corridor&nbsp; of&nbsp; spread.&nbsp; Of&nbsp; the&nbsp; 26 invasive plant taxa whose presence&nbsp; was recorded and&nbsp; analysed&nbsp; in&nbsp; the&nbsp; riparian&nbsp; areas&nbsp; of&nbsp; Serbia,Xanthium strumarium&nbsp; subsp.&nbsp; italicum,&nbsp; Amorpha fruticosa,&nbsp; Erigeron&nbsp; canadensis,&nbsp; Robinia pseudoacacia&nbsp; and&nbsp; Echinochloa&nbsp; crus-&nbsp; galli&nbsp; were taxa&nbsp; with&nbsp; the&nbsp; highest&nbsp; number&nbsp; of&nbsp; records.Catchment&nbsp; areas&nbsp; of&nbsp; the&nbsp; Danube,&nbsp; Južna&nbsp; Morava, Zapadna&nbsp; Morava&nbsp; and&nbsp; Timok&nbsp; rivers&nbsp; were characterised&nbsp; by&nbsp; the&nbsp; highest&nbsp; levels&nbsp; of&nbsp; invasion. Based&nbsp; on&nbsp; their&nbsp; distribution&nbsp; data,&nbsp; cover&nbsp; and abundance of the analysed taxa, catchment areas of&nbsp; the&nbsp; Danube,&nbsp; Kolubara&nbsp; and&nbsp; Zapadna&nbsp; Morava rivers&nbsp; are&nbsp; highlighted&nbsp; as&nbsp; the&nbsp; main&nbsp; corridors&nbsp; of spread for the majority of the studied IAS. Four habitat&nbsp; types&nbsp; stand&nbsp; out&nbsp; by&nbsp; the&nbsp; number&nbsp; of analysed IAS. Taxa which were recorded in the highest&nbsp; number&nbsp; of&nbsp; habitat&nbsp; types&nbsp; are:&nbsp; Amorpha fruticosa,&nbsp; Erigeron&nbsp; canadensis,&nbsp; Robinia pseudoacacia,&nbsp; Echinochloa&nbsp; crus-galli&nbsp; and Xanthium strumarium subsp. italicum.&nbsp; A number of&nbsp; physical&nbsp; and&nbsp; hydromorphological&nbsp; parameters and&nbsp; dominant&nbsp; anthropogenic&nbsp; influences&nbsp; of&nbsp; the studied&nbsp; field&nbsp; sites&nbsp; were&nbsp; shown&nbsp; to&nbsp; affect&nbsp; the presence&nbsp; and&nbsp; abundance&nbsp; of&nbsp; the&nbsp; studied&nbsp; invasive plants.&nbsp; The catchment areas of the Sava, Velika Morava&nbsp; and&nbsp; Južna&nbsp; Morava&nbsp; rivers&nbsp; are&nbsp; excpected to&nbsp; be&nbsp; under&nbsp; a&nbsp; strong&nbsp; pressure&nbsp; of&nbsp; the&nbsp; spread&nbsp; and dominance&nbsp; of&nbsp; IAS&nbsp; unnder&nbsp; the&nbsp; conditions&nbsp; of global&nbsp; climate&nbsp; changes.&nbsp; Riparian&nbsp; areas&nbsp; in&nbsp; the southwestern parts of Serbia (valleys of&nbsp; Lim and Ibar&nbsp; rivers&nbsp; and&nbsp; their&nbsp; tributaries)&nbsp; and&nbsp; riparian zones&nbsp; in&nbsp; the&nbsp; mountain&nbsp; and&nbsp; high- mountain&nbsp; areas are also expected to experience an increase in the number&nbsp; of&nbsp; invasive&nbsp; species&nbsp; and&nbsp; their&nbsp; spread rates.</p>

The aim of the study was to find benefits derived from the natural propagation and the use of guava plants and fruit by people living in rural areas of KwaZulu-Natal, looking at guava as a source of food, income, medicinal uses, shade, a source of fuel and use for agricultural purposes like fencing; and also assessing Conservation of the Agricultural Resource Act (CARA), Act 43 of 1983 relating to guava plant as invasive species. The Act states that all alien invader species and weeds should be controlled or removed depending on the category. CARA states that plants in category one are declared as alien invasive plants and are not allowed to grow on the land or appear on the water surface. Plants under this category may not be transported or allowed to disperse e.g. Psidium x durbanensis (Durban guava). Category two plants are invader species that have a potential value, plants that are used by the people as a source of income and food. These species can be retained if they grow in special areas demarcated for the purpose (an orchard). If these species are found outside demarcated areas they are to be removed e.g. Psidium guava (guava). Category three species are mostly plants with ornamental value which are not allowed to occur anywhere unless they were already in existence when the regulation came into effect e.g. Psidium guineense (brazillian guava) and Psidium cattleianum (strawberry guava). The study focused on selected areas of KwaZulu-Natal,: Umgungundlovu district municipality (Richmond local municipality) and Uthungulu district municipality. Richmond represented the midlands areas and Uthungulu the coastal areas to reflect two different areas of KwaZulu-Natal. To investigate this study the researcher used telephonic interviews with 23 Extension officials, questionnaires to guide focus group discussions which were conducted with 28 community groups that were involved in guava usage. Informal observation surveys were also carried out with five markets (stall holders) selling guava and guava products. Informal observations in two supermarkets and two home industries were also conducted. The results showed that people in rural areas still use this resource (guava) as a source of fuel (wood), medicine (especially the leaves and bark), fruit for own consumption (either processed or raw) and income generation. The impact of the legislation on rural poor communities is negative as guavas sustain livelihoods and the costs of applying for permits are prohibitive. People are illiterate yet they have to apply for special permits to plant this useful species because the regulation stipulates that guava plants must be controlled if dispersed outside demarcated areas. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.