Savanna Landscapes Research Articles

Associations between Lantana camara L. (Verbenaceae) and common native species in an African savanna

Abstract Lantana camara L. (Verbenaceae) is recognised as a problematic invasive alien plant species in many parts of the world. To eradicate or control this global invader, we need to understand the drivers of its spread and impacts and the potential for native recovery after the invader has been removed. Here, we tested for species associations between L. camara and native plant species and large herbivores in Queen Elizabeth National Park, Uganda. We inventoried 40,100‐m2 nested plots spread over a 1 × 1‐km grid cell in the park's savanna landscape, with 11 plots located in uninvaded areas. Most of the plots (30 of 40) had been affected by fire. Lantana camara covered 29 (73%) plots, 11 (38%) of which were in open grassland. Of the large herbivores that frequented areas free of L. camara, the Ugandan kob Adenota kob thomasi Sclater tended to avoid the areas invaded. The floristic composition of invaded areas differed significantly from that of noninvaded areas, with several palatable species rare or absent from L. camara‐invaded areas. Practical implication: These observations indicate the presence of potential recovery constraints that will need to be overcome after L. camara has been removed. Sustained efforts will be needed to suppress the invader and subsequently enrich and bolster native recovery.

Exploring the West African forest island phenomenon: scientific insights gained, successes achieved and capacities strengthened.

Anthropogenic activities around local villages in mesic savanna landscapes of West Africa have resulted in soil improvement and forest establishment outside their climatic zones. Such unique 'forest islands' have been reported to provide ecosystem services including biodiversity conservation. However, the science underpinning their formations is limitedly studied. In 2015 and with funding support from the Royal Society-DFID (now FCDO), we set out to investigate the biogeochemistry of the forest islands in comparison with adjacent natural savanna and farmlands across 11 locations in Burkina Faso, Ghana and Nigeria. Our results showed that the forest islands do not differ significantly from the adjoining ecosystems in soil mineralogy implying that their formation was anthropogenically driven. We observed greater soil organic carbon and nutrient distributions in the forest islands, which also had more stable macro (>500 μm) and meso-aggregates (500-250 μm) than the adjoining agricultural lands. We found that soil micro-aggregate (250-53 μm) stability was climate (precipitation) driven in the West African ecosystems while meso- and macro-aggregate stability was land-use driven. In one of the unique forest islands we studied in the Mole National Park of Ghana, we found its mineral-associated organic carbon over 40% greater than the adjoining natural savanna with potential implications for the achievement of the global initiative of the '4p1000' in West Africa. We conclude that the North-South-South research collaboration has established clearly, the science underlying the age-long West African forest island phenomenon and has, among many successes, led to capacity building of young scientists driving cutting-edge research in climate change adaptation and food systems transformation in the sub-region.

A survey of nocturnality and risk for savanna chimpanzees at Assirik, Senegal.

Chimpanzees (Pan troglodytes) in Senegal may use nocturnality to mitigate hyperthermia risk in semi-arid environments but the degree of nocturnality for such chimpanzees also in sympatry with large carnivores remains uncertain. We compared diel activity among chimpanzees and their potential predators at Assirik in Niokolo-Koba National Park and contextualized these findings relative to other unit-groups in savanna landscapes. From 2015-2018, we generated a predator inventory using multi-modal methods and monitored the diel activity of chimpanzees and predators with camera traps [ N = 2092 camera trap (CT) days]. From 2015-2023, we also surveyed for evidence of predation during recce walks. Six potential nonhuman predators occur at Assirik, including lions (Panthera leo), leopards (Panthera pardus), spotted hyenas (Crocuta crocuta), African wild dogs (Lycaon pictus), Nile crocodiles (Crocodylus niloticus), and rock pythons (Python sebae). We documented one suspected case of a predator killing a chimpanzee. Nocturnality comprised 12.7% of CT events for chimpanzees and these events were more concentrated at twilight. Chimpanzees were more active during the day, predators were more active at night, and there was substantial temporal overlap among chimpanzees and potential predators during twilight intervals. Our findings support the hypothesis that savanna chimpanzees in Senegal are active at night in response to the extremely hot environment. We hypothesize that Assirik chimpanzees experience a tension between decreasing hyperthermia and increasing predation risk during nocturnality.

Soil geochemistry and constraint of tree seedlings immediately after germination on Macrotermes termite mounds in the Kruger National Park, South Africa.

Macrotermes termite mounds in the Kruger National Park occupy a significant part of the savanna landscapes, occurring at densities of up to 70 km-2 and often exceeding 10 m in width and 4 m in height. The mounds are usually devoid of trees, but have dense grass cover in wet years. As a result, these mounds form large patches of grassland amongst the wooded savanna. To our knowledge, it is not known why trees are largely excluded from the mounds. We analysed soil surface nutrient concentrations on and off mounds (0-2 cm deep, n = 80) to ascertain whether the availability of nutrients could be influencing competition between grasses and tree seedlings. The results showed that potential deficiencies in P, Ca, Cu, Zn and B in soils off the mounds are likely to be constraining plant growth. Notably, only B, with an average concentration of 0.19 mg kg-1, was likely to be limiting plant growth on the mounds. Notwithstanding likely interactions with herbivory and fire, we hypothesise that because grasses are far less susceptible to deficiencies of B than dicotyledonous trees, it is likely that grass competition with tree seedlings is considerably greater on mounds than off mounds.

Soil properties of thickets and adjacent land use types in coastal savanna landscape of Ghana

Thicket vegetation may be of great importance in soil carbon (C) storage and in provision of other ecosystem services such as soil erosion control and biodiversity conservation. However, it is less studied in tropical ecosystems due to limited understanding of its ecological importance. This study reports soil C pools and nutrient concentrations [nitrogen (N), available phosphorus (P), exchangeable calcium (Ca), magnesium (Mg) and potassium (K)] of unique thicket formations on Vertisol in comparison with adjacent land use types viz. rangeland, dry forest, and farmland at Kpong in the coastal Accra plains of Ghana. We also examined soil particle and nutrient distributions of termitarium associated with the thicket clumps on the Vertisols. Soils were sampled from each land use at 0–30 cm depth in addition to deep coring up to 100 cm. In the rangeland, forest and farmland, we demarcated 1600 m2 area each and established 4 subplots measuring 20 × 20 m (400 m2) and selected for the thicket vegetation, 4 thicket clumps each of approximately 400 m2 for soil sampling. The thicket clumps had greater soil total N, available P, exchangeable Ca and Mg concentrations than the rangeland and farmland but the levels in the thicket were similar (p > 0.05) to that of the adjacent dry forest. Soil C stock varied from 59 Mg ha−1 in the rangeland to 111 Mg ha−1 in the thicket clumps. The C stored in the silt + clay (S + C) fraction did not differ significantly (p > 0.05) in both the thicket and the dry forest, indicating similar C sequestration abilities. The S + C fraction contributed 89.6, 82.8, 81.3, and 73.7% to total soil organic C content in the rangeland, farmland, dry forest, and thickets, respectively. Soils of the termite mounds in the thickets were more clayey (ca. 38–41% clay) than the surrounding thicket soils (ca. 32% clay). We conclude that Vertisols in thicket areas store soil C and nutrients comparably as tropical dry forest, underscoring their ecological importance and the need for their conservation to enhance soil quality in the Anthropocene.

Habitat connectivity of threatened ungulate species in a native savanna landscape of northern South America

AbstractThe native savanna ecosystem of the Orinoquia region is the habitat of 50% of the wild ungulate species reported for Colombia. Over the last 20 years, this high species diversity has been strongly threatened by the human transformation of the natural land cover causing connectivity loss of the habitats. The Orinoquia region lacks a biological connectivity analysis with a multi-species approach involving species groups that are representative of the savanna ecosystem such as the ungulates. Understanding the spatial distributions of suitable areas and the main habitats that act as primary habitats for ungulate species in these landscapes is fundamental for the design of conservation strategies. We use an occurrence dataset for lowland tapir (Tapirus terrestris), white-tailed deer (Odocoileus virginianus), and white-lipped peccary (Tayassu pecari) in the development of species’ potential distribution models, binarization process, and morphological spatial pattern analysis. This information was used for the modeling of dispersal corridors connecting the core habitats of the ungulate focal species using the randomized shortest path algorithm and quantifying the weighted global connectivity metrics. Our results suggest an integral corridor with potential least-cost dispersal routes between the native savanna landscape on the middle basins of the savanna rivers and the Meta River. These areas associated with the fluvial dendritic systems are connected, while the core habitats in the eastern part of the savanna landscape are disconnected. We discuss how the application of such knowledge on the spatial ecology of ungulate focal species might improve the management of the metapopulations in the Orinoquia region.

Management Strategies of Tropical Savanna Ecosystem for Multiple Benefits of Community Livelihoods in Semiarid Region of Indonesia

Tropical savannas are complex landscapes composed of mainly grasses and a matrix of proportions of discontinuous tree cover. They play an essential role in providing multiple ecosystem services including biodiversity, carbon storage, and socio-economic and cultural values. However, knowledge of sustainable land management practices is still the main challenge, especially to incorporate conservation practices and well-planned fire management. Indonesia is a tropical country with a relatively large area of savannas in the eastern part of the country, in the province of East Nusa Tenggara, with the largest savannas lying in the east of Sumba Island. This study explored the level of knowledge, behaviours, and actions in managing savannas in the east of Sumba Island. The study involved key informant interviews and household surveys among the local population in four villages of Kanatang and Kota Waingapu districts. The communities generally utilized the savanna ecosystems for crop cultivation, plantation farming, and livestock production. This utilization poses a great challenge to explore proper strategies for managing the savanna landscapes sustainably and for conservation. The demands on the land are due to land clearing for farming and livestock, low awareness of conservation practices, and regular drought. Learning from this research, management strategies to sustain savanna ecosystems should focus on: 1) improving knowledge and behaviour on sustainable farming and grazing practices, 2) establishing proper fire management systems to sustain the savanna ecosystem functions and services, 3) designing policies or regulations for managing savanna ecosystems, 4) enhancing networks and coordination for collective community actions.

Effects of herbivory, fire, and vegetation type on soil compaction and aggregate stability in a semi-arid savanna

AbstractVegetation type is an important component of savannas contributing to changes in soil health. In savanna landscapes, the tree-grass balance is primarily governed by water, nutrients, fire, herbivory, and their interactions. Here we investigated the long-term effect of herbivores, fire, and vegetation type, and their interactions on selected physical properties (bulk density, penetration resistance, aggregate size fractions, and mean weight diameter (MWD)) of water stable aggregates within the crest and foot-slope of 20-year-old Nkuhlu exclosures located in Kruger National Park, South Africa. Burning, herbivory, and open grassland zones had a significant main and interactive ecological impact on all the soil physical properties under investigation. The interactions between fire, herbivores, and vegetation type within the crest and foot-slope of the Nkuhlu exclosure had a significant impact on soil bulk density, with areas under tree canopies having lower bulk density than open grassland zones in all the exclosures. In all the sampling sites, both burnt and unburnt plots of the full exclosure had lower penetration resistance than the control site and partial exclosure. Moreover, unburnt plots and canopy cover increased aggregate size distribution and mean weight diameter of water stable aggregates. Since fire and herbivory are closely linked and bring about changes in soil physical properties, the understanding of the dynamics of fire, herbivory, vegetation, and their interactions can then be used to help make effective management decisions that incorporate concerns of biodiversity in savanna ecosystems.

Soil carbon, nutrient, and vegetation dynamics of an old Anogeissus grove in Mole National Park, Ghana

AbstractFormation of forest islands in West Africa has been linked to anthropogenic soil improvement resulting in luxuriant tree growth in otherwise open savanna landscapes. However, there is limited understanding of how such unique ecosystems modulate soil carbon (C) dynamics and nutrient cycling. In this study, we report soil nutrient characteristics and two distinct soil organic carbon pools of Anogeissus grove (forest island) associated with abandoned village sites of the Mole National Park in the Guinea savanna or tropical continental climatic zone of Ghana, taking opportunity of a previously published study in Biotropica in 1978. We compared present‐day differences in soil characteristics between the previously studied forest grove and adjoining open savanna in the Park and evaluated vegetation dynamics since first measurement in 1974. Overall, we see changes related to self‐thinning and expansion of the grove on a decadal timescale. Soil organic matter and available phosphorus contents were greater in the grove and increased by 19.6% and 18.7%, respectively over time, showing persistence after four decades. Mineral‐associated organic carbon (MAOC) differed significantly (p < .05) between the vegetation types, being 3.44% in the grove and 2.34% in the savanna. The grove was ca. 25% greater in particulate organic carbon (POC) content than the savanna. In both vegetation types, >55% of carbon was stabilized in the mineral fraction. Our study demonstrates long‐term human impacts on soil and vegetation and offers a clear nature‐based solution for climate change mitigation through sustainable land management by indigenous people toward achievement of the “4p1000” initiative.

Factors influencing space-use and kill distribution of sympatric lion prides in a semi-arid savanna landscape.

Understanding lions' (Panthera leo) space-use is important for the management of multi-species wildlife systems because lions can have profound impacts on ecosystem-wide ecological processes. Semi-arid savanna landscapes are typically heterogeneous with species space-use driven by the availability and distribution of resources. Previous studies have demonstrated that lions select areas close to water as encounter rates with prey are higher and hunting success is greater in these regions. Where multiple lion prides exist, landscape partitioning is expected to follow a despotic distribution in which competitively superior prides occupy high-quality areas while subordinates select poorer habitats. In this study, Global Positioning System collar data and logistic regression were used to investigate space-use and hunting success among 50% of lion prides at Malilangwe Wildlife Reserve, Zimbabwe. Our findings show that lion space-use was driven by surface water availability and that home range selection was socially hierarchical with the dominant pride occupying habitat in which water was most abundant. In addition, we found that the effect of shrub cover, clay content and soil depth on kill probability was area specific and not influenced by hierarchical dominance. Where multiple lion prides are studied, we recommend treating prides as individual units because pooling data may obscure site and pride specific response patterns.

Environmental and Anthropogenic Predictors Influence the Diversity of Nonflying Mammals in a Native Savanna Landscape of Northern South America

The native savannas of eastern Colombia cover about six percent of the Neotropical savannas. Within these 17 million hectares, the current composition of nonflying mammals evidenced colonization from Andean, Guyanese, and Amazonian speciation centers and endemism processes. Scientific knowledge of the mammal species in native savanna ecosystems in Colombia remains limited. We assessed (a) the species alpha and beta diversity of mammal assemblages and trophic guilds, (b) the influence of environmental predictors on mammal species diversity, and (c) the conservation status of species at both international and national levels. Our sampling included 213 camera trap stations with a total of 25.560 camera trap days. We reported 31 species from 19 families and 10 orders. The mammals best represented by the average relative abundance index (RAI) were Tayassu pecari (RAI = 0.83, n = 2.936) and Cuniculus paca (RAI = 0.33, n = 1.491), and the omnivore group was the most diverse trophic guild. The best‐fitting generalized additive model for location, scale, and shape (GAMLSS) (GAIC = 1305.3) indicated that the diversity of the mammal species detected at camera trap stations was influenced by environmental predictors, including (a) distance to the burned area (burned = p > 3.6 × 10−9) and (b) distance to human infrastructure (built‐up = p > 5.05 × 10−7). Sixteen percent of the mammal species reported are classified as threatened by the International Union for Conservation of Nature (IUCN), while 22% are listed as threatened by Colombia. In addition, 58% fall into the categories of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). We discussed the high plains native savannas as a diversity hotspot for Neotropical mammals. However, this important mammal’s habitat is currently under threat due to human infrastructure and the increasing frequency and intensity of forest fires.

Vegetation-rainfall coupling as an indicator of ecosystem state in a heterogeneous landscape

Coexisting vegetation types in tropical landscapes can respond in contrasting ways to rainfall, despite being in the same climatic envelope. Understanding such heterogeneity in vegetation-rainfall interactions is key for predicting how ecosystems might respond to future environmental changes. Here we test whether temporal coupling between vegetation greenness and rainfall is a good indicator of ecosystem state in the landscape. For this, we study a well-preserved landscape of the Brazilian Cerrado that is formed by mosaics of contrasting ecosystems, including savannas, dry forests and gallery forests. First, we correlate the time-series of rainfall and vegetation greenness to quantify their coupling for each vegetation type. We then compare vegetation-rainfall coupling with other state variables, such as local-scale vegetation structural and functional traits, as well as differences in environmental conditions in which these vegetation types exist. Coexisting vegetation types are set in contrasting local-scale environmental conditions and have distinct responsiveness to rainfall. Commonly used structural and functional state variables, such as tree cover and tree height, do not depict such marked differences between the vegetation types, particularly for gallery and dry forests. Dry forests have the strongest coupling and decrease their greenness during dry seasons, reflecting vegetation deciduousness on nutrient-richer soils. In contrast, gallery forests increase their greenness during the dry season, when direct radiation peaks, likely due to perennial access to groundwater. Savannas are less responsive to rainfall and have a more stable greenness throughout the year. Our findings suggest that heterogeneity in local abiotic conditions contribute to determining both vegetation distribution and ecosystem states in these tropical savanna landscapes. Changes in these conditions as a result of climate and land-use changes will likely alter the distribution of vegetation types in the future. Our functional metric may thus be useful for assessing future responses of tropical ecosystems to changes in precipitation.

Community Forest Associations Boundaries and Sustainable Forest Management in Loita Forest, Narok County, Kenya

The Kenya Forest Act of 2005, subsequently revised in 2016, introduced the Kenya Forest Service and its mandate to engage in Participatory Forest Management (PFM) agreements with local communities adjoining state forests. This framework necessitated the establishment of Community Forest Associations (CFAs) nationwide, including the Loita Community Forest Association. However, a prevailing concern surrounding CFAs is the delineation and redefinition of boundaries, an issue that has gained prominence due to Kenya's decentralized forest governance system and the ambiguity surrounding the management of locally-held common resources. This study centers on investigating the process of establishing boundaries for the CFAs both in forest resources and the users within Loita Forest in Narok County, Kenya. Notably, Loita forest operates under a Traditional Participatory Forest arrangement, controlled by community elders, led by the revered Oloibon, who steers the resource utilization decisions. The vast expanse of Loita forest encompasses both lush woodlands and savanna landscapes. Employing purposive sampling, the study engaged 52 respondents from nine distinct Loita sub-locations. Key informants were interviewed individually, complemented with focus group discussions conducted with the use of semi-structured questions. Participant observation further enriched data collection, consolidating insights from key informants and group discussions. Collected data was meticulously tape-recorded and subjected to summative content analysis. The inquiry delved into the practicality of existing traditional resource-use boundaries, the adequacy of governmental regulations, policies, and institutions in elevating forest governance within Kenya, and the extent to which individual indigenous rights have been upheld in managing and using communal forest resources. Key findings of this study show that the Loita Maasai still values their traditional norms and have great respect for cultural institutions. Major decisions concerning the management of Loita forest are made by the council of elders led by the Chief Laibon. The study also found that there exists no CFA in Loita forest and that the presence of government institutions in the forest is minimal. This study's outcomes contribute to a nuanced understanding of the intricate interplay between indigenous wisdom, modern frameworks, and sustainable forest management. It underscores the indispensable role of tradition in shaping boundaries, governance, and ecological equilibrium within Loita forest and offers practical directives for future forest management endeavors.

Reflections on the Dynamics of Savanna Landscapes

Savanna landscapes are shaped by the interactions of disturbances with land use goals. Elephant hunting in a site in Botswana, and its consequences for wildlife, people, and landscapes, are described and discussed in order to make broader generalizations about the dynamics of savanna landscapes. Change comes from alterations in tree-grass interactions, fire regimes, predator-prey relations, livestock raising, and conservation goals. Some of these implications are specific to African landscapes, but others may be apt in global contexts.

Impacts of agrochemical intensification and spatial isolation on the assembly and reassembly of temporary pond metacommunities

Abstract Since the Green Revolution, the management of agrochemicals has become a cornerstone of agriculture, allowing it to expand over terrestrial ecosystems previously deemed unsuitable for cultivation. Such expansion altered the connectedness of aquatic habitats to organisms with complex life cycles by increasing the number of temporary ponds in interfluves. Here, we investigate how spatial isolation and intensification in the use of agrochemicals can interact to increase or decrease the permeability of agricultural fields to these organisms by affecting community structure in temporary ponds. We carried out a field experiment that simulates realistic scenarios of agrochemical contamination at different levels of spatial isolation. We constructed 45 1200‐L artificial ponds in a Savanna landscape in Brazil at three distances from a source wetland (30, 120, and 480 m). The ponds were spontaneously colonized by aquatic insects and amphibians and treated with no agrochemicals (control), fertilizers (as in managed pastures) or fertilizers and a single pulse of the insecticide fipronil and the herbicide 2,4‐D (as in sugarcane fields) following realistic dosages and application schedules. Communities treated only with fertilizers generally exhibited a higher abundance of aquatic insects at the peak of the rainy season, suggesting that fertilization caused bottom‐up effects. However, because low spatial isolation and fertilization favoured different predatory taxa, their insect prey eventually became less abundant in less isolated fertilized ponds. Communities treated with fertilizers and pesticides diverged strongly from other treatments after the application of the insecticide, when a decrease in insect abundance indirectly benefitted amphibian populations. In this case, spatial isolation delayed the recovery of the abundance of several herbivore and detritivore insects in isolated ponds. Synthesis and applications. These results have direct consequences for the emergence of insects and amphibians, possibly affecting important ecosystem services. Such consequences can be controlled by avoiding agrochemical contamination at the peak of most taxa reproductive season or through changes in spatial isolation by deliberately constructing wetlands in interfluves. In all cases, the effects of agrochemicals and isolation must be addressed jointly for a successful management of biodiversity in agricultural landscapes.

Reciprocity and beyond: Explaining meat transfers in savanna-dwelling chimpanzees at Fongoli, Senegal.

To understand the function of food sharing among our early hominin ancestors, we can turn to our nonhuman primate relatives for insight. Here, we examined the function of meat sharing by Fongoli chimpanzees, a community of western chimpanzees (Pan troglodytes verus) in southeastern Sénégal. We tested three non-mutually exclusive hypotheses that have been used to explain patterns of food sharing: kin selection, generalized reciprocity, and meat-for-mating opportunities. We analyzed meat sharing events (n = 484) resulting from hunts, along with data on copulations, age-sex class, and kinship to determine which variables predict the likelihood of meat sharing during this study period (2006-2019). We found full or partial support for kin selection, direct reciprocity, and meat-for-mating-opportunities. However, the analyses reveal that reciprocity and a mother/offspring relationship were the strongest predictors of whether or not an individual shared meat. The results of this study emphasize the complexity of chimpanzee meat sharing behaviors, especially at a site where social tolerance offers increased opportunities for meat sharing by individuals other than dominant males. These findings can be placed in a referential model to inform hypotheses about the sensitivity of food sharing to environmental pressures, such as resource scarcity in savanna landscapes.

Balanced Functional Herbivore Composition Stabilizes Tree-Grass Coexistence and Productivity in a Simulated Savanna Rangeland Ecosystem

Savanna ecosystems provide resources supporting the livelihoods of millions of people globally. Ongoing exploitation through high livestock densities, among other factors, however, threatens these ecosystems. Shrub encroachment, a consequence of this exploitation, causes severe declines in fodder biomass for cattle. For example, in Namibia, this leads to losses of land productivity of up to 100%. Consequently, we must rethink land-use options to ensure sustainable utilization of savanna resources. In southern Africa, many landowners and custodians have switched to or included wildlife in their management systems, making it an excellent model region to study how changing herbivory affects ecosystems. The diversity of indigenous wildlife species is expected to promote efficient herbaceous layer utilization with browsing herbivores counteracting nondesirable woody plant encroachment. Nevertheless, surprisingly little research has been conducted on the ecological consequences of altering grazer-to-browser ratios.We developed a large-scale spatially explicit dynamic vegetation model including key hydrological and ecological processes, fire, and an herbivore algorithm that accounts for aggregated animal herds in a heterogeneous savanna landscape. We find that different ratios of wild herbivore feeding types greatly influence vegetation composition and dynamics. By dynamically computing plant biomass as a resource, our model estimates the occurrence of fodder biomass shortages, providing a valuable tool for land users. The model also reports the number of patches with low to medium tree functional cover (10–25%), indicating structural diversity with its implications for species richness, and is thus essential for nature conservation. We find that a herbivore species composition of approximately 40% browsers and 60% grazers is beneficial for plant structural and species diversity. Theoretically, therefore, the browse-graze ratio achieved through wildlife-based land-use can lead to more sustainability and resilience. The interplay between diverse herbivory, vegetation, rain, and fire complicates but also stabilizes the savanna rangeland ecosystem and may contribute to its long-term persistence.

The impacts of Cape porcupines on woody plant mortality

AbstractIn terrestrial ecosystems, the activities of semi‐fossorial animals such as Cape porcupines have important landscape effects that may manifest in the dry season when the availability of above‐ground forage becomes limiting. We investigated the effects of foraging activities of Cape porcupines on savanna landscapes. We measured the size (surface area and depth) of foraging holes of porcupines located at the base of trees in the dry season in two mesic savanna sites at Roodeplaat Farm and Bisley Valley Nature Reserve in South Africa. We also recorded plant and animal activities inside the foraging holes for 3 months. The depth of foraging holes beneath small trees (Vachellia nilotica) was greater than depths beneath old trees (V. robusta and D. rotundifolia). This resulted in the subsequent death of most (>50%) small impacted trees in the dry season at Bisley. The surface area of foraging holes for older trees was greater than that for small trees and even greater for old holes. This study showed that porcupines kill trees or expose them to secondary attacks. The physical impacts of semi‐fossorial herbivores in savannas can be significant, with contributions to direct and indirect landscape transformation and restoration.

Landscape dynamics of the aeolian savanna: Santos Luzardo National Park 1988–2018

This research defines the savanna aeolian landscape dynamics of the ‘Santos Luzardo’ National Park in the Llanos of Venezuela between 1988 and 2018, using images from the LANDSAT series to elaborate and compare ecosystems maps. The ecosystem dynamics show that the landscape changes naturally since the transitions occurred towards other types of natural savanna due to soil water seasonality. The savannas are the dominant matrix of the landscape, occupying between 69.1 and 76.7%. The dynamics of transformation of the aeolian savanna landscape are mainly associated with soil water content. The application of temporal studies contributes to understanding the aeolian savanna landscape transformation processes and evaluating their conservation status.

A dynamic simulation model to assess farm-level effects of pasture intensification strategies on beef herd outputs and carbon footprints in acid soil savannas of Eastern Colombia

The neotropical savannas of Eastern Colombia (Llanos) are subjected to changes in land use associated with intensification of beef production and there is limited knowledge on the long-term impacts of these change processes. Furthermore, the effects of spatial and temporal intensification at farm level via the introduction of sown pastures on beef herd outputs, their greenhouse gas (GHG) emissions and the resulting carbon (C) footprints in contrasting savanna landscapes of of the Llanos are unknown. This study was aimed to assess the consequences of gradual system intensification via introduction of sown tropical pastures in two contrasting landscapes, the tillable, flat savannas and the highly dissected rangelands, of the well-drained Eastern savannas of Colombia, in terms of cow-calf production and GHG emissions and the resulting C footprints. A dynamic model was developed to simulate the gradual introduction of two types of tropical pastures in a region with dissected and steep slopes and limited tillable areas where cattle would also have access to Serrania savanna and sown pastures, versus one located in the Plains that are fully transformed over time with the exclusion of native rangelands. Marked changes in herd demography, animal outputs, and emissions were found over time. The C footprint of all systems varied over time depending upon the length of time that pastures contributed to soil organic carbon accumulation and the balance between savanna and sown pasture areas at a whole farm level. In conclusion, the dynamics of the systems subject to intensification were marked and were dependent on the temporal and spatial deployment of sown forage resources. Therefore, generalizing the trends for the region as a whole result in uncertainty. Nevertheless, examination of simulated prototypes may shed light on the expected trends and provides guidance for decision-making