Effect of livestock management and services to ecosystems on rangeland health and resilience in the NamaKaroo
- Authors: Boshoff, Mishak
- Date: 2023-04
- Subjects: Livestock – Management --South Africa—Karoo , Range ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60611 , vital:66017
- Description: Rangelands offer great opportunities for mutualisms between nature conservation and economic productivity if positive feedback loops can be identified and described. The effects of different livestock management practices are controversial. This research examined the effect of different grazing intensities on soil health using springtails (Collembola) and ants (Formicidae) as bioindicators, combined with soil and vegetation variables. The relationship between rangeland managers and rangeland ecosystems, particularly with regard to feedback loops between land care and economic production, was also investigated. Bioindicator samples were collected at different treatments of livestock grazing intensity and a questionnaire was submitted to 65 rangeland managers in the semi-arid Nama-Karoo biome of South Africa. In most cases we found no significant relationship between grazing intensity and Collembola and ant community composition, vegetation variables, and soil variables. The few significant relationships we found were contradictory in their implications for the effect of high intensity grazing on soil health. The results suggested that differences in livestock management are relatively unimportant for soil health, at least in semi-arid systems under conditions immediately following a drought. The questionnaire yielded results on outline of management practices, basis of management decisions, consequences of monitoring veld to inform management decisions, and indicators of successful management. Respondents characterized by higher ecological fluency focused on livestock production when making management decisions, stocked at higher densities, and monitored the rangeland ecosystem to inform their decisions. For monitoring the ecosystem, they used bioindicators such as diversity of biota, successional stage, and ecologically important functional groups. We concluded that the development of ecological knowledge in rangeland managers enables the establishment of feedback loops between ecosystem services and services to ecosystems, which are desirable for economic productivity and nature conservation. Development of relevant ecological knowledge and management techniques should be based on forums and dialogue among rangeland managers, developing distributed cognition and resilience in the community of rangeland managers. , Thesis (MSc) -- Faculty of Science, School Natural Resource Science and Management, 2023
- Full Text:
- Date Issued: 2023-04
Investigating the effectiveness of microcatchments at enhancing transplant performance in Nama-Karoo riparian ecosystem restoration
- Authors: Jackson, Andrew St. John , Wigley, Benjamin , Schumann, Bonnie , Currie, Bianca
- Date: 2016
- Subjects: Arid regions agriculture , Environmental degradation , Range ecology
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/7469 , vital:21782
- Description: Globally agricultural rangelands have been subjected to degradation through over-utilization. The loss of productivity of agricultural rangelands around the world has led to the development of methods to restore the productivity of these areas. In South Africa, extensive areas of the Nama-Karoo have been degraded or transformed due in part to unsustainable agricultural activities. The development of restoration methods which are easily implementable and financially viable could increase the probability of stakeholders implementing restoration activities on privately owned land. The removal of the degrading factor is not sufficient to reverse the degradative trend in dryland environments. Active measures must be implemented to arrest the degradation cascade. The climatic conditions of the rangelands of South Africa are limiting to plant performance and the favourable conditions are sporadic. The translocation of plants should be combined with the amelioration of the local conditions. This study tested the restoration technique of microcatchments in association with plant translocation. The effects of microcatchments and planting combinations which were best suited to the survival and performance of the transplants were determined through a field trail. The results showed that microcatchments created microsites which were conducive to transplant survival and growth, including nutrient accumulation and increased soil moisture. The success of the method was dependent on the planting combination used. Plants which are adapted to inundation and the saline conditions of the site performed better. Plants which were older at the time of translocation had higher survival rates than younger transplants. In the conditions of this site, planting adjacent to the microcatchments was necessary to avoid inundation induced mortalities. The environmental conditions of the Nama-Karoo necessitate the coordination of restoration activities with the predicted favourable conditions in order to improve the success of restoration activities.
- Full Text:
- Date Issued: 2016
Long-term ecological effects of rangeland burning, grazing and browsing on vegetation and organic matter dynamics
- Authors: Ratsele, Clement Ratsele
- Date: 2013
- Subjects: Rangelands -- Fire management , Range ecology , Rangelands -- Monitoring , Animals -- Effect of fires on
- Language: English
- Type: Thesis , Doctoral , PhD (Pasture Science)
- Identifier: vital:11582 , http://hdl.handle.net/10353/d1006844 , Rangelands -- Fire management , Range ecology , Rangelands -- Monitoring , Animals -- Effect of fires on
- Description: To proffer a sustainable solution to ecological degradation in rangeland ecosystems as a consequence of fire, grazing and browsing, an understanding of rangeland ecological processes is vital. Due to the complexity of ecological processes and their interrelationships, it is usually difficult or expensive to directly measure status of ecological processes. Therefore, biological and physical characteristics are often used to indicate the functionality of ecological processes and site integrity. Long-term effects of fire, grazing and browsing on characteristics of the vegetation and organic matter and their subsequent effects on selected rangelands ecosystem ecological processes was conducted at Honeydale section of the University of Fort Hare farm in the Eastern Cape Province of South Africa and Matopos Research Station in Zimbabwe. In this study, attributes of biotic community integrity (species richness, composition and diversity), soil stability (basal cover, standing dead grass biomass, tuft to tuft distance, tufts diameter, canopy distance and stem to stem distance), productivity and plant vigour (grass yield, total canopy volume, plant height, canopy height, canopy diameter, main stem diameter, sprouts diameter and number of sprouts) and hydrologic function and nutrient cycling (grass litter biomass, soil organic carbon and microbial biomass carbon) were used to estimate long-term effects of burning, grazing and browsing by goats on the functionality of ecological processes in the rangeland ecosystem. Burning did not have differential effect on grass species richness (P>0.05), woody species diversity as well as compositional percentage for D.eriatha, C.plurinodis, S.fimbriatus, A.karro and E.rigida. Burning increased decreasers and increaser II species proportions and reduced (P ≤ 0.05) grass yield, total canopy volume, tree height, canopy height main stem diameter and sprouts diameter. Long-term burning, grazing, and goats browsing had differential effects on site stability. The effects on basal cover, tuft to tuft distance, tufts diameter, canopy distance and basal distance as a consequence of long-term burning, grazing, and goats browsing were not significantly different, whereas the effects on standing dead grass biomass as a result of long-term burning frequencies were significantly different. Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on tuft-tuft distance but did not have statistically different effects on tufts diameter, canopy distance and basal distance. Long-term burning grazing and browsing had significantly different effects on attributes of hydrologic functions and nutrient cycling in the rangeland ecosystem (grass litter biomass, SOC and BMC). Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on grass litter biomass, and SOC. Through their effect on vegetation and organic matter characteristics, burning, grazing and browsing could influence functionality of selected rangeland ecological processes such as biological community integrity, productivity and plant vigour, site stability, hydrologic function and nutrient cycling.
- Full Text:
- Date Issued: 2013