Klaus Kellner

• PhD
• Senior Researcher at North-West University

Aims Shrub encroachment is a major challenge for livestock and wildlife management in semi‐arid savannas. Shrub removal by land managers is widespread, but the long‐term effects on vegetation structure and composition, which determine carrying capacity for herbivores, are poorly documented. This study aims to examine the effects of selective shrub...

Land degradation due to bush encroachment and drought threatens the well-being of land users and forage production in the semi-arid savannas of southern Africa. This study aimed to analyse how herbaceous vegetation in the Kalahari savanna can recover from drought, and how this is affected by previously implemented bush control measures. We compa...

Climate change and inappropriate management practices in semi-arid savannas often result in shrub encroachment. Chemical shrub control is a common rehabilitation measure to counter shrub encroachment. A recent development, particularly in southern Africa, is the conversion from cattle to wildlife farming. Cattle and wildlife exhibit different behav...

Most semi-arid savannahs in South Africa are being degraded by bush encroachment, resulting in a decline in biodiversity. Four restoration treatments consisting of bush clearing, brush packing, reseeding and a combination of clearing, reseeding and brush packing were tested. Grass diversity was measured in a communal and conservation area using the...

Oral presentation: Savanna landscapes consist of a dynamic mosaic of patches in varying degrees of co-dominance between the grassy and woody components. Many different factors acting at various scales determine the current state of the savanna patches, such as heterogeneous precipitation patterns, soil moisture, vegetation competition and successi...

Read more on this article at; https://www.tandfonline.com/eprint/EIC9E4SXF2QZZEKECGMJ/full?target=10.2989/10220119.2022.2086620 Large-scale bush encroachment within rangelands is of increasing concern for land users. The aggressive encroachment of the woody shrub Seriphium plumosum (L.) Thunb. (Asteraceae), previously known as Stoebe plumosa, has...

Various factors lead to increased woody species density, biomass and cover (so-called ‘bush encroachment’) that influence ecosystem functioning and services in semi-arid rangelands. Ultimately, bush encroachment has adverse effects on human livelihoods. An increased understanding of ecosystem functioning in bush-encroached rangelands could contribu...

Evidently, bush encroachment caused by factors, such as overgrazing, results in a change in savanna ecosystems. This shift in vegetation structure can affect many factors, including insect fauna. Epigeal arthropods occupy smaller habitat patches and therefore respond to the effects of bush encroachment at finer scales. Different restoration efforts...

In this paper we celebrate this milestone by giving an overview of the history of the Department at this campus, including its recent establishment and expansion on the NWU Mahikeng Campus (formerly the University of NorthWest). A brief overview is presented of the advances in teaching and research over the years, and the development and relevance...

Background: One of the main causes of land degradation in South Africa is bush thickening (BT) of mainly Senegalia or Vachellia species. Restoration methods are required to control BT, and to improve grass biomass production and soil conditions in South Africa.Objectives: The objectives of this study were to determine the effect of brush packing (B...

Bush encroachment involves a widespread increase in, and abundance of, woody vegetation in grassland and savanna biomes. This phenomenon has a direct impact on the socio-economic well-being of rural communities and affects livestock owners and those who utilise the land for various other purposes. This study set out to evaluate and gain an understa...

This study aimed to investigate the socio-economic benefits stemming from bush clearing and restoration projects conducted in the Lephalale municipality, within the Limpopo Province of South Africa. The study was conducted at two sites: the D’Nyala Nature Reserve and a nearby local village, Shongoane. A qualitative thematic content analysis approac...

South Africa undertook a national Land Degradation Neutrality (LDN) target setting process during 2017/18 in response to the United Nations Convention to Combatting Desertification’s call for signatory countries to voluntarily commit to LDN as also requested under Sustainability Development Goal 15.3. The process was supported by the Global Mechani...

https://www.acemap.info/paper/278415444. https://www.semanticscholar.org/paper/Data-Portal-Query-on-Data-references-in-CSV-format%2C-Day-Kumar/a1ec6d8d87a79c2a7c32e58bae6737d5954333f1 Keywords: Information retrieval; Computer science; data portal

Bush thickening (shrub encroachment) is a major ecological and economic threat in southern African savannas. Different types and intensities of bush control (BC) are applied to counteract and mitigate bush thickening. However, woody vegetation response to BC and possible ecological side effects can be manifold. Land users therefore require solid kn...

Savannas can be defined by the co-dominance of grasses and trees. Interactions between these two life forms are relatively well studied, whereas tree-tree interactions attracted increased attention only recently. However, the influence of woody plant density on tree-tree interactions is rarely considered. We studied tree-tree interactions in a semi...

Classification of grass species of the Molopo Bushveld savanna into functional groups based on selected (composite) traits. Besides expert knowledge, related information was compiled from Fouché et al. (2014), Müller (2007), Roberts and Fourie (1975), and van Oudtshoorn (2012).

While effects of bush thickening (woody plant encroachment) on biodiversity were studied for a range of animal taxa or taxonomic groups in Kalahari environments, similar studies for plant taxa or functional groups are rather scarce. We analyzed response pattern in richness and evenness at the plant taxonomic and growth form level using data collect...

Southern Africa south of 150° S latitude includes all or part of several countries. The situation in the dryland portion of each of them is described and the underlying factors are explained. Land degradation affects significant areas of most of the countries. Measures taken to arrest and reverse land degradation are explained. Climate change, tren...

Bush encroachment is a syndrome of land degradation that occurs in many savannas including those of southern Africa. The increase in density, cover or biomass of woody vegetation often has negative effects on a range of ecosystem functions and services, which are hardly reversible. However, despite its importance, neither the causes of bush encroac...

Senegalia mellifera var.detinens is an increaser woody species and serious bush encroacher of semi-arid Savannas in the North-West Province, South Africa. Large areas of the Molopo Bushveld have been transformed from a grassy tall open savanna of dominating Vachellia erioloba and Boscia albitrunca trees to a closed S. mellifera thicket nearly devoi...

The United Nations Convention to Combat Desertification (UNCCD) has lacked an efficient mechanism to access scientific knowledge since entering into force in 1996. In 2011 it decided to convene an Ad Hoc Working Group on Scientific Advice (AGSA) and gave it a unique challenge: to design a new mechanism for science-policy communication based on the...

Savanna rangeland systems are used for livestock and/or game farming. Degradation of these systems leads to an increase in the density of the woody component (shrubs & trees), also called “bush encroachment” (BE), which causes an imbalance in the woody: grass ratio due to a competition of moisture and nutrients. In restoration practices, various ar...

The chemical control of thickened woody savanna layers is a common practice applied in southern Africa to release the grass layer from competitive pressure and restore the economic viability of rangelands. We comparatively assessed the composition, density and production of the grass layer in relation to the woody vegetation structure following the...

The arid southwestern dunefield of the Kalahari is characterized by open savanna vegetation covering linear dunes intersected by dune streets. Farming with small-stock is common in the area and particularly dependent on the grassy forage production of the dune streets. Locally, the increaser shrub Rhigozum trichotomum encroaches the streets and, in...

A high proportion of South Africa’s semi-arid Molopo Bushveld is thickened by indigenous increaser shrubs and trees as a result of ill-adapted grazing management and suppression of fires. A common approach to restore a balanced and productive woody:grass ratio in this savanna is the use of systemic, soil-applied arboricides. If larger areas need to...

Bush encroachment is one of the forms of land degradation in South Africa. The dramatic increase of woody species which suppress grass growth has serious ecological and economic consequences such as reduced carrying capacity for domestic livestock and game. However, the driving forces behind these dynamics remain still mainly unknown. Our ultimate...

Monitoring of land degradation in remote rangelands, such as the Kalahari Duneveld, presents significant logistical challenges because of the need for systematic measurements of rangeland condition over time and space. The distinct vegetation dynamics and manifestation of degradation on dunes and interdunes in the Kalahari Duneveld, and their edaph...

Land management evaluation can be made more relevant and holistic by incorporating local knowledge and perspectives. We examined whether photo elicitation and photovoice could enhance semi-structured interviews in capturing local livestock farmers’ knowledge and perspectives in a participatory evaluation in Mier and Molopo, South Africa. The partic...

Urbanisation creates altered environments characterised by increased human habitation, impermeable surfaces, artificial structures, landscape fragmentation, habitat loss, resulting in different resource loss pathways. The vulnerable Rand Highveld Grassland vegetation unit in the Tlokwe Municipal area, South Africa, has been extensively affected and...

The IUCN Eastern and Southern Africa Regional Office (ESARO) is implementing the Kalahari Namib Project (KNP) to enhance decision-making in rangeland management through interactive environmental learning and action in the Molopo-Nossob River Basin in Botswana, Namibia and South Africa (SA) and the European Commission funded project on Securing Righ...

Natural remnants, such as fragmented grasslands form an integral part of the urban green infrastructure in the Grassland biome of South Africa. Nearly 30 % of natural grasslands are transformed with only 1 % formally conserved. Since grassland habitats are globally regarded as a biodiversity conservation priority, protection should be accorded outs...

Desertification is a major environmental problem in South Africa with serious socio-economic consequences. Despite enormous efforts made to understand its causes and best management to combat desertification, little is known about the relation between land users' perspectives on land management and their actual practice. This study used the types o...

The loss of ecosystem resilience and land productivity is a major problem in drylands of southern Africa. This needs to be addressed in an integrated way linking science to society. Identifying best practices for land restoration and sustainable land management in a process combining local and scientific knowledge is therefore very important as reg...

Bush encroachment is a serious problem in savanna rangelands of southern Africa. There is a strong interest in practical and reliable assessment methods to quantify related vegetation changes in the woody layer such as the widely applied point-centred quarter (PCQ) methods. Several variations of these distance methods exist but their results differ...

Wildfires can have significant impacts on rangeland productivity and functionality causing substantial economic losses to affected farmers. In August 2011, such wildfires swept through the North-West Province of South Africa, destroying large areas of grazing and farm infrastructure. There is little information available, how the regional semi-arid...

This study forms part of the multinational PRACTICE project (Prevention and Restoration Actions to Combat Desertification: An Integrated Assessment) aiming at developing and testing an integrative assessment protocol (IAPro) for restoration and management practices to mitigate or prevent land degradation. Land users in the Mier and Molopo areas in...

Bush encroachment is a serious problem in the semi-arid savannas of southern Africa, which has forced land users to apply active and passive mitigation practices to improve or sustain rangeland conditions. Technologies to control bush encroachment mainly include chemical control or sustainable management strategies, such as rotational grazing. The...

Dryland degradation and the related loss of ecosystem services is a major threat to biodiversity and livelihoods of local land users. Coupled effects of increasing anthropogenic pressures, unsustainable land management and climate change alter ecosystem resilience and may result in profound shifts of socio-ecological environments. It is due to thes...

Rangeland management and research in savannas needs practical and reliable assessment methods to quantify compositional and structural changes of the vegetation. Two adapted point-centered quarter methods (APCQM) were tested in the Kalahari Bushveld of South Africa, in order to compare their performance in estimating density and productivity parame...

The over-utilization of semi-arid savanna rangelands in the North-West Province of South Africa has resulted in profound habitat transformations. A common regional indicator of rangeland deterioration is the imbalance in the grass:woody ratio characterized by a loss of grass cover with increased shrub or tree density. This can result in profound re...

Die doel van hierdie studie was om die kronologiese opeenvolging van plantegroeivestiging opgerehabiliteerde goudslikmyn damme met behulp van biomassa, samestelling en bedekking van grasspesies te evalueer.

The Grassland biome is the most transformed biome in South Africa, with cultivation and other human impacts having the largest effect on pristine grasslands. Conversion of natural grassland to cropland agriculture destroys natural vegetation seed banks. When croplands on the South African Highveld are abandoned, secondary succession often leads to...

Although sustainable land management (SLM) is widely promoted to prevent and mitigate land degradation and desertification, its monitoring and assessment (M&A) has received much less attention. This paper compiles methodological approaches which to date have been little reported in the literature. It draws lessons from these experiences and identif...

The United Nations Convention to Combat Desertification and its sister conventions, the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity, all aim to halt or mitigate the deterioration of the ecological processes on which life depends. Sustainable land management (SLM) is fundamental to achieving the g...

Die tipe veldherstel behandeling wat gebruik word in gedegradeerde weivelde hang van die graad van agteruitgang af. Gedegradeerde areas wat reeds verby die drumpel van natuurlike herstel is, benodig gewoonlik aktiewe ingryping. Dit sluit die versteuring van die grondoppervlak of die verwydering van ongewenste en uitheemse spesies wat kompeteer met...

For many years, rangeland monitoring has mainly been the field of scientists, academics and extension workers trying to fine-tune methods to assess the condition of rangelands. Frameworks and monitoring systems developed with their associated indicators are often complex and inaccessible to land users who lack the advanced equipment to implement th...

Differences in land-use management may result in different rangeland condition (soil, vegetation and biodiversity) and productivity. Vegetation condition in contrasting land-use management systems is well documented in semiarid rangelands, but relatively little information is available on soil quality. This study explores soil quality indicators in...

In recent years, the concept of watershed management has grown rapidly due to the importance of water as an increasingly precious natural resource that is, at the same time, very difficult to manage within the overall development of any nation. Watersheds integrate many physical, biological, social and economic processes and information. Water reso...

Livestock grazing and detrimental overgrazing are commonly associated with severe rangeland degradation particularly in communally managed pastoral systems in South Africa. Effects of grazing exclusion on vegetation are well documented, but there is a dearth of quantitative research conducted in communal managed range- lands to investigate the exte...

The establishment of the Mapungubwe National Park has been an objective of several conservationists for many years. The ultimate objective is that this park should become a major component of a Transfrontier National Park shared by Botswana, Zimbabwe and South Africa. The aim of this study was to identify, classify and describe the plant communitie...

Soil microbial biomass is considered as an important early indicator of changes that may occur in the long term with regard to soil fertility and constitutes an important source and sink of nutrients. In South Africa, rangeland monitoring has mostly focused on assessing changes of aboveground vegetation in response to land uses effects, but the ass...

The aim of the study was to identify and classify the woodlands, bushland and grasslands of the Umkhanyakude Integrated Sustainable Rural Development Node (also known as Maputaland) into homogenous management units to assist with the natural resource audit and monitoring program initiated by the Department of Agriculture. The Node is situated in Kw...

It is known that, depending on the degree of degradation, the vegetation recovery of severely degraded areas by means of natural succession processes is very slow, if not impossible, and that active intervention in the form of restoration technologies has to be applied.Combinations of different restoration technologies, including ripping, over-sowi...

Combating desertification in natural rangelands has recently become a priority in large parts of southern Africa. Rangeland managers, farmers, scientists, conservationists and land users have been applying a variety of restoration technologies to address this problem. Bush encroachment, as part of the desertification process, involves the natural r...

There has been an accelerated expansion of deserts in the past five decades. Recent data reveal that the atmogenically formed organic compound, trichloroacetic acid (TCA) is a contributory factor in addition to anthropogenic and natural sources. The aim of this study was to use TCA as an indicator for the possible occurrence of C2-chloroacetic acid...

We analyzed data sets on phytomass production, basal cover, and monthly precipitation of a semiarid grassland in South Africa for good, medium, and poor rangeland condition (a) to investigate whether phytomass production per unit of basal cover differed among rangeland conditions, (b) to quantify the time scales of a carryover effect from productio...

During the past five decades, the expansion of deserts has accelerated in many regions of the earth including sub-Saharan Africa. Both climatic changes and the over-exploitation of natural resources in these regions have been considered to be responsible for this phenomenon. Recent data, however, revealed an additional factor that may contribute to...

The germination potential of seed banks along a degradation gradient in a semi-arid grassland in South Africa was quantified in a greenhouse experiment. Soil samples were collected to a depth of 50 mm in late June 2000 from four sample sites, namely: bare soil, as well as veld in good, moderate and poor condition. The sample sites represented a veg...

The establishment of the Vhembe-Dongola National Park has been an objective of several conservationists for many years. The ultimate objective is that this park would become a major component of a transfrontier park shared by Botswana, Zimbabwe and South Africa. The aim of this study was to identify, classify and describe the plant communities pres...

Human and natural interactions in the earth’ s vast drylands have global-scale influences. Dryland ecosystems play a major role in global biophysical processes by reflecting and absorbing solar radiation, maintaining a balance of atmospheric constituents, and sustaining biomass and biodiversity. A continuously increasing human population and demand...

A phytosociological study was conducted as an initial assessment of the vegetation on ash disposal sites to determine the community structure of vegetation and how the communities were related based on their species composition and habitat characteristics. The Braun-Blanquet survey and data analysis method was used to identify and classify plant co...

An important component of any ecosystem is the species it contains. Species also serves as good indicators of the ecological condition of a system. A list of all species collected during the three-year period was therefore compiled together with their life form spectra. The floristic composition of the ash disposal area at Hendrina Power Station wa...

Trichloroacetic acid (TCA; CCl3COOH) is a phytotoxic chemical. Although TCA salts and derivatives were once deployed as herbicides against perennial grasses and weeds, their use has since been banned because of their indiscriminate herbicidal effects on woody plant species. However, TCA can also be formed in the atmosphere. For instance, high-volat...

Ecological monitoring of rehabilitated plant communities can be useful to improve the management of rehabililated areas.

A survey of mechanized rehabilitation methods attempted by rangeland managers was carried out. Two types of cultivation methods have commonly been used in parts of South Africa to combat further degradation and to improve the production potential. Depending on money and time it was found that certain cultivation methods were only suitable under cer...

In semi‐arid regions, the effects of grazing or sparing management on natural communities of long‐lived plants generally take decades to become evident. Event‐driven dynamic behaviour, unpredictable and low rainfall, and complicated interactions between species make it difficult to gather sufficient understanding of vegetation dynamics to be able t...

This paper describes a participatory research process designed to gather and structure community knowledge (local and scientific) into a single accessible decision support system, based on case-based reasoning methodologies. Special reference is made to the continuous enhancement of the knowledge base through research (by scientists), and implement...

Multivariate analytical procedures are used on data representing different condition states. The model is then used as a basis for the ecological interpretation of condition assessments in 4 different management units. -from Authors