• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 11
  • 11
  • 5
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design of an automated system for imaging and sorting soil mesofauna /

Chamblin, Mike A. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 55-56). Also available on the World Wide Web.
2

MATHEMATICAL MODELLING OF SOIL DIVERSITY INDICES UNDER DIFFERENT USES AND MANAGEMENTS

SILVA, Raimunda Alves 06 March 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-10-04T20:06:24Z No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5) / Made available in DSpace on 2017-10-04T20:06:24Z (GMT). No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5) Previous issue date: 2017-03-06 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão / ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of Maranhão state, Brazil. It were installed 130 pitfall traps in five areas with different management (millet, soybean, maize, eucalyptus, and pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. The geostatistical analysis was evaluated by a semivariogram, adjusted to a geostatistical, spherical, gaussian or exponential model. The multifractality was analyzed by the current method, in successive segments of different sizes of 2k , k=0 a k= 7 in the range of q = +10 to q = -10. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability. For the areas of millet, maize, eucalyptus, anthropized Cerrado and pasture the Shanon diversity index obtained pure nugget effect. For the areas of millet, maize, anthropized Cerrado and pasture, the total diversity index was adjusted to the gaussian model. Only for the areas of soybean and pasture the staggered semivariograms showed similarity in the spatial variability of indexes, indicating that they behave similarly. The multifractality generated generalized dimension, D0, for all the indexes in the millet area, with invariant values, D0 = 1.000 ± 0.000. The singularity spectra were curves in concave parables with greater or smaller asymmetry for all areas sampled. In general, the fauna of soil presented spatial variability and multifractal parameters. / ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of the State of Maranhão, Brazil. Were installed 130 pitfall traps in five areas with different management (Millet, Soybean, Maize, Eucalyptus, and Pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability.
3

A comparison of biomarkers in assessing the combined effects of pesticide mixtures on non-target soil invertebrates

Gola, Nontuthuzelo Pearl 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Agricultural environments are usually contaminated with mixtures of antropogenically introduced chemicals as a result of pesticide spraying, which can affect beneficial, nontarget soil invertebrates, such as earthworms negatively. Most studies on mixture toxicity have focused on interactions of chemicals with similar structures and mechanisms. However, chemical mixtures may occur as conglomerates of diverse structures and toxicological mechanisms in the environment. This study was aimed at assessing the effects of pesticides singly, and in a mixture, on earthworms, using lifecycle parameters (growth and reproduction) and biomarkers (neutral red retention (NRR) assay and acetylcholinesterase (AChE) inhibition) as endpoints. Thus, to determine whether any interactions occurred between the pesticides as shown by the measured endpoints. Another aim was to validate the use of the chosen biomarkers for assessing mixture toxicity. The pesticides used were from three groups: organophosphates, heavy metal-containing pesticides and pyrethroids. From these three groups, four of the most commonly used pesticides in the orchards and vineyards of the Western Cape, South Africa, were chosen, namely chlorpyrifos (organophosphate), azinphos-methyl (organophosphate), copper oxychloride (heavy metal-containing fungicide) and cypermethrin (pyrethroid). Earthworms were exposed in the laboratory to a range of concentrations of chlorpyrifos and copper oxychloride singly, and in 1:1 mixtures of these pesticides in artificial soil, for four weeks. After the exposure period, the biomass change was determined as measure of growth, and cocoon production, hatching success and number of hatchlings per cocoon were determined as measures of reproduction. Growth (biomass change) and reproduction (cocoon production) were affected by the highest concentration treatment (20mg/kg) of chlorpyrifos, but copper oxychloride and the mixture of the two pesticides showed no observable effects on lifecycle parameters. Dose related effects on NRR times were however determined for both pesticides and the mixture. Dose related effects on AChE activity were found for chlopyrifos and the mixture of the two pesticides, but not for copper oxychloride. Short-term exposures (48 hours) of earthworms to the following pesticides in artificial groundwater: chlorpyrifos, copper oxychloride, azinphos-methyl, cypermethrin, chlorpyrifos-copper oxychloride, chlorpyrifos -azinphos-methyl and chlorpyrifos-cypermethrin, were done followed by the determination of AChE inhibition. Dose related effects were exhibited on the AChE activity of earthworms exposed to chlorpyrifos, a mixture of chlorpyrifos and copper oxychloride, azinphos-methyl, and a mixture of azinphos-methyl and chlorpyrifos. Copper oxychloride, cypermethrin and the mixture of chlorpyrifos and cypermethrin had no effect on AChE activity. Earthworms died at the highest exposure concentration of the mixture of chlopyrifos and cypermethrin. Results have shown that although the pesticides did not cause observable effects on lifecycle parameters, there were effects at subcellular and biochemical level, as shown by the biomarkers. Mixtures of pesticides, in some instances, affected earthworms differently from their single components, indicating interactions between the pesticides in mixtures, as shown by the measured endpoints. The NRR assay proved to be a good general biomarker of soil contamination, and the AChE activity could also be a valuable tool in assessing the effects of organophosphate mixtures and mixtures of organophosphates and pesticides from other groups. / AFRIKAANSE OPSOMMING: Nie-teiken organismes, soos erdwurms, word negatief beïnvloed deur mengsels van antropogeniese chemikalieë in landbou-omgewings. Die meeste studies wat handel oor die toksisiteit van chemiese mengsels het tot dusver gefokus op chemikalieë van dieselfde aard en met dieselfde meganismes van werking. Mengsels van chemiese stowwe kan egter as konglomerate van 'n verskeidenheid strukturele eienskappe en met verskillende toksiese meganismes in die omgewing aangetref word. Tydens die studie is gepoog om die effekte van enkel pestisiede sowel as mengsels daarvan op erdwurms te bestudeer, deur van lewensloop kenmerke (groei en voortplanting) en biomerkers (neutraalrooi retensietyd - NNR en inhibisie van asetielcholienesterase -AChE) as eindpunte gebruik te maak. 'n Verdere doel van die studie was om vas te stel of daar enige wisselwerkings tussen die verskillende pestisiede plaasvind, soos aangetoon deur die gemete eindpunte, en verder ook om die gebruik van die gekose biomerkers as maatstawwe van mengseltoksisiteit te evalueer. Die pestisiede wat gebruik is, is van drie verskillende groepe afkomstig: organofosfate, swaarmetale en piretroiede. Van hierdie drie groepe is vier van die pestisiede wat vry algemeen in boorde en wingerde in die Weskaap, Suid-Afrika, gebruik word, geïdentifiseer. Hierdie stowwe is chlorpyrifos (organofosfaat), azinphos-metiel (organofosfaat), koperoksichloried (swaarmetaalbevattende fungisied) en sipermetrien (piretroied). Erdwurms is in die laboratorium aan 'n reeks konsentrasies van chlorpyrifos en koperoksichloried as enkel toksikante en as 1:1 mengsels in kunsmatige grond, vir vier weke blootgestel. Voor en na die blootstellingsperiode is die biomassa van die wurms, as maatstaf van groei, bepaal en kokonproduksie, uitbroeisukses en getal nakomelinge per kokon bepaal as maatstawwe van voortplantingsvaardigheid. Groei (biomassaverandering) en voortplanting (kokonproduksie) is beinvloed deur behandeling met die hoogste konsentrasie (20 mg/kg) chlorpyrifos, terwyl geen effek van koperoksichloried of die mengsel van hierdie twee pestisiede gevind is nie. Daar is gevind dat beide die pestisiede, enkel en in die mengsel, die NRR tye beinvloed het. Die AChE aktiwiteit is beinvloed deur chlorpyrifos en die mengsel, maar nie deur die koperoksichloried nie. Korttermyn blootstellings van erdwurms (48 uur), in kunsmatige grondwater, van erdwurms aan chlorpyrifos, koperoksichloried, azinphos-metiel en sipermetrien as enkel toksikante en mengsels van chlorpyrifos-koperoksichloried, chlorpyrifos-azinphos-metiel en chlorpyrifos-sipermetrien, is gedoen en gevolg deur die bepaling van AChE inhibisie. Koperoksichloried, cypermetrien en die chlorpyrifos-sipermetrien mengsel het geen waarneembare effek op die AChE aktiwiteit gehad nie ?????. Die erdwurms wat blootgestel is aan die hoogste konsentrasie in die mengsel van chlorpyrifos-sipermetrien het doodgegaan. Die resultate het getoon dat die pestisiede nie in die korttermyn die lewensloopkenmerke in enige waarneembare mate geaffekteer het nie maar daar was effekte op sellulêre en biochemiese vlakke soos aangetoon deur die biomerkers. Sommige mengsels van die pestisiede het die erdwurms verskillend van die enkelstowwe geaffekteer. Daar het dus wisselwerking tussen sommige van die pestisiede wat in mengsels aangewend is, plaasgevind, soos aangetoon deur die gemete eindpunte. Die NRR toets, as breë-spektrum biomerker was 'n goeie maatstaf van kontaminasie in grond en daar is aanduidings dat die AChE aktiwiteit, as 'n spesifieke biomerker, 'n nuttige maatstaf kan wees om die effekte van organofosfaatmengsels en mengsels van hierdie chemiese groep en die van ander chemikalieë aan te toon.
4

The bioavailability of trace metals to soil invertebrates in urban contaminated soils /

Kennette, Debra. January 1997 (has links)
Bioavailability of trace metals in urban contaminated soils was investigated to relate chemical extraction efficiencies with biological effects. / Results from a Collembola reproduction bioassay showed minimal toxicity suggesting limited bioavailability. Chemical extractions were carried out on these urban soils. The sodium acetate extraction was the best predictor of the biological effects of Cd while the biological effects of Zn were best explained by a water extraction. / An earthworm uptake bioassay was done to quantify the bioavailable fractions. Cadmium, Cu, Pb and Zn accumulated in Lumbricus terrestris L. The sodium acetate extraction was the best predictor of Cd uptake while calcium chloride extraction best predicted Zn uptake by earthworms. / Treatments were made to urban soils to immobilize the metals and reduce their bioavailability. The metal concentrations were so low in the soils that the effects of the treatments could not be measured. / Collembola and earthworms are good indicators of trace metal bioavailability and should be included in the evaluation of contaminated soils.
5

Spatial relationships of vesicular-arbuscular mycorrhizae, soil fauna and soil nutrients in the juniper-sagebrush-grass communities of central Oregon /

Roberts, Christine, January 1994 (has links)
Thesis (M.S.)--Oregon State University, 1994. / Typescript (photocopy). Includes bibliographical references (leaves 140-143). Also available on the World Wide Web.
6

The bioavailability of trace metals to soil invertebrates in urban contaminated soils /

Kennette, Debra. January 1997 (has links)
No description available.
7

Towards a unified allometric and stoichiometric perspective in ecology / Soil communities and decomposition in focus of the metabolic theory and the ecological stoichiometry

Ott, David 07 September 2014 (has links)
No description available.
8

Indicadores da qualidade do solo em uma cronossequ?ncia sob sistema plantio direto em Gua?ra - PR / Soil quality indicators along a chronosequence of no-tillage system in Gua?ra - PR

FERREIRA, Cl?udia dos Reis 25 April 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-19T19:18:26Z No. of bitstreams: 1 2016 - Cl?udia dos Reis Ferreira.pdf: 1425765 bytes, checksum: d847a95493845c76aaaf6f7635662069 (MD5) / Made available in DSpace on 2018-09-19T19:18:26Z (GMT). No. of bitstreams: 1 2016 - Cl?udia dos Reis Ferreira.pdf: 1425765 bytes, checksum: d847a95493845c76aaaf6f7635662069 (MD5) Previous issue date: 2016-04-25 / CAPES / To manage properly the natural resources and also to produce with sustainability is a big challenge. Conservation management practices, such as no-tillage system (NTS), intend to increase the sustainability of agricultural systems through improvement of chemical, physical and biological soil attributes. This work was developed in private rural systems, explored commercially in Guaira municipality ? Paran? State. Three different areas were evaluated, with NTS adoption time of 7, 14 and 23 years, with succession of soybean (summer) and corn/wheat crops (winter) (NTS7, NTS14 and NTS23, respectively), and an area of Atlantic Forest as reference. The sampling was taken in the dry season (September/2013), after harvesting corn, and in the rainy season (February/2014), after harvesting soybean; to evaluate effect of duration of soil usage and management under the different crops in NTS on edaphic attributes. The hypothesis tested were: a) long duration management systems can change physical, chemical and biological soil properties; b) the crop succession with grass/legumes species (corn/soybean) promotes modifications in the groups of soil macrofauna and, consequently, in the compartments of soil organic matter (SOM); and c) the season of sampling (winter and summer) influences the composition of soil macrofauna and in the SOM compartments. They were analyzed chemical attributes and total organic carbon (TOC) and nutrient stocks (Ca, Mg, K and P), particle size, aggregates stability, bulk and particle densities, actual soil moisture, calculated the total volume of pores, and evaluated the edaphic macrofauna, at the depths of 0-0.1, 0.1-0.2 and 0.2-0.3 m. The morphological types of aggregates were identified, establishing three groups: physiogenic, intermediates and biogenic. For the different groups it was measured the relative composition, TOC, and physical and chemical fractionation of organic matter. In general, the variation in chemical properties were related to NTS time and the sampling season, which also reflects the soil coverage. Soybean and corn/wheat succession contributed to increase contents and stocks of carbon, Ca and P in the different NTS chronosequences. Although there was no significant difference between the areas, the increasing bulk density values observed with depth in the NTS23 area, with longer system adoption, indicate compacted layers that should be monitored. The highest density and total richness of macrofauna individuals were found in the NTS14 and NTS23 areas under corn residues, but there were not observed higher indexes of equability, due to dominance of Formicidae and Isoptera groups. The areas with the highest equability values were the reference, in the dry season, and NTS23 in the rainy season, with values to 0.87 and 0.61, respectively. The biogenic aggregates were found in larger proportion in the reference area, while the physiogenics and intermediate predominated in the managed areas. The TOC contents were higher in biogenic aggregates, as well as organic carbon associated with minerals (OCam). The humin fraction showed no significant differences in the dry season, while in the rainy season the humin content was higher in physiogenic aggregates. This result indicates that biogenic aggregates of the dry season change into the physiogenic aggregates found in the rainy season. / Gerenciar adequadamente os recursos ambientais e simultaneamente produzir de forma sustent?vel ? um grande desafio. Pr?ticas de manejo conservacionistas, como o sistema plantio direto (SPD), visam aumentar a sustentabilidade dos sistemas agr?colas atrav?s da melhoria dos atributos qu?micos, f?sicos e biol?gicos do solo. O trabalho foi desenvolvido em sistemas agr?colas particulares, explorados comercialmente no munic?pio de Gua?ra ? PR. Foram avaliadas tr?s ?reas com diferentes tempos de ado??o do SPD, por 7, 14 e 23 anos sob sucess?o das culturas soja (ver?o) e milho/trigo (inverno) (SPD7, SPD14 e SPD23 respectivamente), e uma ?rea de Floresta Atl?ntica como refer?ncia. As amostragens foram feitas no inverno ap?s a colheita das culturas de milho (setembro/2013), e no ver?o, ap?s a colheita de soja (fevereiro/2014). O objetivo foi avaliar o efeito do tempo de uso e manejo do solo sob diferentes coberturas em SPD sobre os atributos ed?ficos. As hip?teses testadas foram: a) sistemas de manejo de longa dura??o podem alterar caracter?sticas f?sicas, qu?micas e biol?gicas dos solos; b) a sucess?o de culturas com esp?cies de gram?neas/leguminosas (milho/soja) promove modifica??es nos grupos da macrofauna do solo e, desta forma, nos compartimentos da MOS; e c) a ?poca de avalia??o (inverno e ver?o) influencia na composi??o da macrofauna do solo e nos compartimentos da MOS. Foram analisados: atributos qu?micos e estoques de carbono org?nico total (COT) e de nutrientes (Ca, Mg, K e P), an?lise granulom?trica, estabilidade de agregados, densidade do solo (Ds) e da part?cula (Dp), umidade atual do solo, calculado o volume total de poros, e avaliada a macrofauna ed?fica, nas profundidades de 0-0,1, 0,1-0,2 e 0,2-0,3 m. Foram identificados os tipos morfol?gicos de agregados, nos tr?s grupos: fisiog?nicos, intermedi?rios e biog?nicos. Para os diferentes grupos, foi medida a composi??o relativa, COT, e fracionamento qu?mico e f?sico ou granulom?trico da mat?ria org?nica. De modo geral, a varia??o nos atributos qu?micos se relacionou com o tempo de implanta??o do SPD e a ?poca de amostragem, que tamb?m refletiu a cobertura do solo. A sucess?o soja, milho/trigo contribuiu no aumento dos teores e estoques de carbono, Ca e P nos diferentes tempos de implanta??o do SPD. Embora sem diferen?a significativa entre as ?reas, os valores de Ds em profundidade na ?rea SPD23, com maior tempo de ado??o, indicam camadas compactadas, que devem ser monitoradas. A maior densidade e riqueza total de indiv?duos da macrofauna foram encontradas nas ?reas SPD14 e SPD23 sob a palhada do milho; por?m n?o foram observados maiores ?ndices de equabilidade, pelo dom?nio dos grupos Formicidae e Isoptera. As ?reas com maiores valores de equabilidade foram a de refer?ncia, no inverno, e a de SPD23 no ver?o, com 0,87 e 0,61, respectivamente. A maior propor??o de agregados biog?nicos foi na ?rea de refer?ncia; j? os fisiog?nicos e intermedi?rios predominaram nas ?reas manejadas. Os teores de COT foram maiores nos agregados biog?nicos, assim como o carbono org?nico associado aos minerais (COam). A fra??o humina n?o apresentou diferen?a significativa na coleta de inverno; no ver?o, a humina foi maior nos agregados fisiog?nicos. Esse resultado indica que os agregados biog?nicos do inverno originaram os agregados fisiog?nicos encontrados no ver?o.
9

Invertebrate diversity in afrotemperate forests : spatial and seasonal changes and implications for conservation.

Uys, Charmaine Janet. January 2006 (has links)
Forests in the Drakensberg Mountains, although generally small and fragmented, represent a wealth of globally significant biodiversity. This is especially true of the invertebrate fauna, which includes a range of localized endemic species. Ground dwelling, flightless invertebrates living in forests show relative immobility and poor dispersal abilities compared to birds, butterflies and other animal taxa. The naturally fragmented state of Afrotemperate forests also geographically isolates these taxa. No quantified, systematic surveys of flightless invertebrates have been conducted in Afrotemperate forests in the Drakensberg Mountains. This means that, to date, invertebrates have not been considered in the management of these habitats. However, invertebrates are vitally important in ecosystem functioning and maintenance and must be included in management plans. This study quantified flightless invertebrate diversity in Afrotemperate forest patches in the Drakensberg by investigating spatial patterns and seasonal changes in invertebrate diversity. The broad objectives were to: 1) Determine the appropriate spatial scale at which conservation of flightless invertebrates should be implemented; 2) Determine which season, taxa and sampling methods are most suitable for biodiversity assessment and monitoring in Afrotemperate forest; and 3) Investigate methods of prioritizing Afrotemperate forests for conservation of flightless invertebrate diversity. Seventeen forest patches in six valleys in four Drakensberg reserves (Rugged Glen Nature Reserve, Royal Natal National Park, Cathedral Peak and Injisuthi) were sampled in the summer of 2004/2005. In addition, three forests at Injisuthi were sampled in March, June, September and December 2004 to enable seasonal comparisons. Sampling methods included soil samples, leaf litter samples, pitfall traps, active search quadrats and tree beats. The study focused on terrestrial molluscs (Class Gastropoda), earthworms (Class Annelida), onychophorans (Class Onychophora), centipedes (Class Chilopoda), millipedes (Class Diplopoda) and ants (Class Insecta). Target taxa were sorted to morphospecies and then identified to species by taxonomic experts. Seventy-two species and a total of 5261 individual specimens from the six target taxa were collected. Species composition of sites varied along the north-south gradient, and species turnover (beta diversity) was related to the distance between sites. Flightless invertebrate species richness and community structure fluctuated seasonally. Therefore, I recommend that sampling should take place during the wet season (summer months). Molluscs were the most suitable taxon among those surveyed to represent flightless invertebrate diversity and leaf litter samples and active search quadrats are the most suitable sampling methods for flightless invertebrates in forest. This study compared approaches to prioritizing Afrotemperate forests in terms of their invertebrate diversity using ranked species richness with complementarity indices of species presence/absence, taxonomic distinctness (orders, families and genera) and endemicity. There was no consistent spatial trend in the priority ranking of forests based on species richness. Complementarity based on species richness only required eight out of 17 forests to represent all 62 species. Although complementarity based on taxonomic distinctness and endemicity required fewer sites, not all species were represented. The minimum set of sites identified using complementarity based on species richness and augmented with information on taxa of conservation importance (local endemic and threatened species) was the most rigorous approach to prioritizing Afrotemperate forest patches in the Drakensberg for flightless invertebrate conservation. Urgent conservation interventions are required because invertebrates play a critical role in ecosystem functioning. As many forest patches and invertebrate populations as possible should be protected to conserve the full complement of invertebrate species of the region. Special management attention should be paid to the eight forests identified as priority sites in the complementarity analyses. Forest patches cannot survive in isolation, so it is important to manage the grassland, riverine vegetation, forest ecotone and forests holistically. Provisional targets were set for the conservation of flightless invertebrates, based on estimates of the requirements for persistence of invertebrates in Afrotemperate forest, made within the constraints of available information and expert opinion. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
10

The Effect of Soil Micronutrient Variation Along an Elevational Gradient in a Wet Montane Forest

Ritzenthaler, Cari 26 July 2017 (has links)
No description available.

Page generated in 0.1041 seconds