Theses and Dissertations (Biology)Theses and Dissertations (Biology)http://hdl.handle.net/10386/9822024-03-28T21:55:35Z2024-03-28T21:55:35ZThe abundance and species richness of the spiders (Arachinda: Aranae) associated with open savanna, woodland and false grassland in the Polokwane Nature Reserve, Limpopo ProvinceModiba, Mokgadi Asnathhttp://hdl.handle.net/10386/44332024-01-26T01:00:08Z2007-01-01T00:00:00ZThe abundance and species richness of the spiders (Arachinda: Aranae) associated with open savanna, woodland and false grassland in the Polokwane Nature Reserve, Limpopo Province
Modiba, Mokgadi Asnath
Lack of professional expertise on the taxonomy and systematics of invertebrates in the country leads to significant problems in understanding the invertebrate biodiversity and causes under appreciation of species. Little knowledge exists about the diversity of arachnids in certain eco regions. South Africa is obliged to develop a strategic plan for the conservation and sustainable use of biodiversity since meaningful conservation cannot take place if the involved species are not known. The South African National Survey of Arachnida (SANSA) was initiated to make an inventory of the arachnid fauna of South Africa. Various projects are underway to prepare inventories of the spider fauna of the different floral biomes and provinces. Surveys of arachnid fauna are more important in conserved areas as conservation strategies are already in place. As part of SANSA, a study was initiated in the Polokwane Nature Reserve during March 2005 until the end of February 2006 to determine the species richness and diversity of spiders associated with Acacia tortillis Open Savanna, Acacia rehmanniana Woodland and the Pietersburg Plateau False Grassland at the Polokwane Nature Reserve in the Limpopo Province. This is the first survey in the area and provides information to SANSA in terms of conserved areas in the Savanna Biome. During this study four sampling methods (sweep netting, tree beating, active searching and pitfall trapping) were used to collect spiders from all the different vegetation layers. They were identified to morpho-species and a checklist of spiders collected was compiled, adding data to the Limpopo Province check list. The composition of the spider community, seasonal abundance patterns, fluctuations and the influence of vegetation structure on spider populations
were determined. A total of 7 776 spiders were caught belonging to 33 families, 131 genera and representing 219 species. Of these species, 153 (69.8 %) were wanderers and 66 (30.2 %) web-builders. The Oxyopidae was the most abundant family (1575), followed by Eresidae 1 554), Thomisidae (1 411), Araneidae (582), Lycosidae (568) and Salticidae (527). The Araneidae was the most species rich family (33) followed by the Thomisidae (31), Salticidae (25), Gnaphosidae (20), Theridiidae (18), Lycosidae (16) and the Philodromidae (12). The seven most abundant species collected during this study were Stegodyphus dumicola (Eresidae) (1 549) followed by two oxyopids, an undescribed oxyopid Oxyopes sp.3 (535) and Oxyopes russoi (476), Runcinia flavida (Thomisidae) (437), another oxyopid Oxyopes pallidecoloratus (384) followed by a lycosid Evippomma squamulatum (282) and another thomisid Monaeses austrinus (201). Immature specimens dominated captures, while females and males peaked during December till March with
the most diverse species found in April. The highest specimen numbers and species richness was caught in the Woodland site (3 520; 173) followed by the Open Savanna (2 823; 159) and the Grassland site (1 433; 115). The Shannon-Weiner diversity index value calculated for species caught in the three different sampling sites was the highest for the Open Savanna site (H’=3.777),
followed by the Woodland site (H’=3.569) and the Grassland site (H’=3.273). During this study the highest number of specimens were caught by sweep netting (2 972), followed by active searching (2 572), tree beating (1 895), pitfall trapping (323) and only a few (14) were caught by one attempt of leaf litter sifting. High evenness values for the Open Savanna (HE=0.748), the Woodland (HE=0.692) and the Grassland sites (HE=0.689) indicated a relatively even distribution of species across these sites. The Bray-Curtis similarities calculated for the methods used to catch species occurring on the three sites was 48 % similar for species caught by sweep netting
and tree beating. Species caught by active searching and pitfall traps were 44 % similar.
Additionally the species caught by leaf litter sifting were only 8 % similar to that caught using the other four methods. Vegetation structure and the time of year influenced the spider community at the Polokwane Nature Reserve. Temporal changes influenced the species richness, diversity as well as the number of mature, identifiable specimens. No work have previously been undertaken in this area and the species collected represent new distribution records for all species collected.The present study made an important contribution towards increasing our knowledge of spider diversity in the Savanna Biome.
Thesis (M.Sc. (Biodiversity )) -- University of Limpopo, 2007
2007-01-01T00:00:00ZAdaptation of smallholder maize farmers to temperature and rainfall variability in Capricorn District Municipality, Limpopo Province, South AfricaMazwi, Kabelo Makadikwehttp://hdl.handle.net/10386/32762021-02-26T01:00:06Z2019-01-01T00:00:00ZAdaptation of smallholder maize farmers to temperature and rainfall variability in Capricorn District Municipality, Limpopo Province, South Africa
Mazwi, Kabelo Makadikwe
Refer to document
Thesis (M. Sc.) -- University of LImpopo, 2019
2019-01-01T00:00:00ZEfficacy determination of paint-brush flower (Klenia longiflora) o suppression of meloidogyne javanica and growth of tomato plantsMoremi, Makgoka Givenhttp://hdl.handle.net/10386/30742020-08-22T01:00:15Z2019-01-01T00:00:00ZEfficacy determination of paint-brush flower (Klenia longiflora) o suppression of meloidogyne javanica and growth of tomato plants
Moremi, Makgoka Given
Plant extracts exhibited broad spectrum of activities against root-knot (Meloidogyne
species) nematodes and had long been considered as an attractive alternative due to
their being biodegradable and posing limited risk hazards to the environment, animal
and human health. Additionally, the materials had been dubbed as being of low-input
costs and had been viewed as being easy to apply in agricultural systems. The
objective of the current study was to investigate the efficacy of paint-brush flower
(Kleinia longiflora) either as fermented or granular formulations on suppression of M.
javanica and their related effects on growth of tomato (Solanum lycopersicum) plants
under field and greenhouse conditions. Fermented crude extracts were applied at 0,
2, 4, 8, 16, 32 and 64%, whereas granular materials were applied at 0, 2, 4, 6, 8, 10
and 12 g. Regardless of the product, the treatments were arranged in randomised
complete block design (RCBD), with 12 replications. Kleinia longiflora plants were
collected from the wild, chopped into pieces, oven-dried at 52⁰C and fermented in
effective microorganisms (EM) for 14 days, whereas the remained were retained for
use as granular formulation. Tomato seedlings cv. ꞌFloradadeꞌ were used as test plants
inoculated with 2500 eggs and second-stage juveniles (J2) of M. javanica. At 56 days
after the treatments, nematode and plant variables were collected, prepared using
appropriate methodologies and subjected to analysis of variance using Statistix 10.0
software to generate means. Plant variables were subjected to the Curve-fitting
Allelochemical Response Data (CARD) computer-based model to generate
appropriate biological indices. Nematode and mineral elements variable means were
subjected to lines of the best fit. Findings showed second-stage juveniles (J2) in roots,
J2 in soil, eggs and Pf under increasing concentration were highly significant and
exhibited negative quadratic relationship. The model explained the associations by 82,
xvii
81, 74 and 76%, respectively. In granular formulation, the product had no significant
effects on nematode population densities. The fermented crude extracts significantly
affected and exhibited positive quadratic relations for dry fruit mass, chlorophyll
content, dry shoot mass, number of flowers, plant height, number of fruit and stem
diameter of tomato plants. The model explained the relationship by 97, 94, 95, 96, 94,
97 and 96%, respectively. In contrast, in granular formulation, the product had
significant effects and positive exhibited quadratic relations on Chlorophyll content
under field and greenhouse, plant height, dry root mass and dry shoot mass. The
model explained the relationships by 52, 45, 56, 47 and 59%, respectively. Plant
variables and increasing concentration of the products exhibited density-dependent
growth patterns for both formulations, with overall sensitivity (∑k) values of 1 and 11,
respectively. In fermented liquid and granular formulations, the Mean Concentration
Stimulation Point (MCSP) values were derived at 1.97% and 2.84 g, respectively. The
increasing concentration of fermented K. longiflora also had significant effects and
exhibited negative quadratic relations on the accumulation of K, Na and Zn in leaf
tissues of tomato plants. The model explained the associations with 87, 94 and 94%,
respectively. In conclusion, the findings in the current study suggested that the
nematicidal chemicals in K. longiflora could not be released through irrigation water
but could be released into solution through microbial degradation. Also, at low
concentration suitable for use without inducing phytotoxicity, the products in either
formulation could improve the accumulation of certain nutrients in leaf tissues of
tomato plants.
Thesis (M. Agric. (Plant Protection)) -- University of Limpopo, 2019
2019-01-01T00:00:00ZAdaptation of xylose fermenting yeasts, isolated from various sources in the Limpopo Province, to improve ethanol production in the biofuel industryTshivhase, Munangiwahttp://hdl.handle.net/10386/19702018-06-14T01:00:13Z2017-01-01T00:00:00ZAdaptation of xylose fermenting yeasts, isolated from various sources in the Limpopo Province, to improve ethanol production in the biofuel industry
Tshivhase, Munangiwa
The recent oil crisis and environmental concerns over fossil fuels has led to the development of biofuels from lignocellulosic materials. Two main sugars from lignocellulose that can be used for bioethanol production are glucose and xylose. Xylose is problematic, because there are few yeasts that can utilise and ferment it. Xylose fermentation is not as efficient compared to glucose fermentation. Some of the factors that affect xylose fermentation include rate of xylose consumption, aeration, temperature and inhibitors. To improve ethanol production and fermentations and to make the process economically viable at industrial scale, there is a need to find a robust microorganism that can ferment efficiently in harsh industrial conditions. Therefore, the aim of this study was to investigate by means of evolutionary engineering (adaptation), the adaptability of seven locally isolated yeasts in terms of growth on high xylose concentration, in the presence of acetic acid as well as at elevated temperatures. Seven yeast strains (Candida guilliermondii MBI2, Candida sp. Kp6.2ey, Candida tropicalis Kp21ey, Candida tropicalis Kp42ey, Candida tropicalis Kp43ey, Ogatea methanolica Kp2ey and Pichia kudriavzevii Kp34ey) were adapted to ferment 60 g/L xylose as sole carbon source in the presence of 3 g/L acetic acid at 37°C. P. kudriavzevii Kp34ey was the only yeast to adapt to these conditions. The adapted P. kudriavzevii Kp34ey was compared with the parental strain (unadapted) and a reference strain, Scheffersomyces stipitis NRRLY-7124, using different volumetric oxygen transfer coefficient (KLa) rates. P. kudriavzevii Kp34ey (adapted and parental strain) and S. stipitis NRRLY-7124 produced the highest ethanol concentrations at a KLa value of 3.3. Overall, for all KLa values tested, the adapted strain performed better than the parental strain and S. stipitis NRRLY-7124. The adapted P. kudriavzevii Kp34ey yielded 4.03 g/L ethanol on 60 g/L xylose with 3 g/l acetic acid at 37°C at a KLa value of 3.3 and was the only yeast tested to grow under these conditions.
Thesis (M. Sc. (Microbiology)) --University of Limpopo, 2017
2017-01-01T00:00:00Z