Large Savanna Research Articles

Soil acidification controls invasive plant species in the restoration of degraded Cerrado grasslands

The Cerrado, South America's largest savanna, has acidic, nutrient‐poor soils and its native plants thrive under these conditions. However, abandoned pastures historically undergo changes in chemical properties due to interventions like liming and fertilizer use. This favors invasive African grasses and hinders native plants, impacting restoration efforts. In a Cerrado grassland undergoing restoration study, we tested whether soil acidification could restore native soil conditions and control invasives using 56 plots across 14 blocks. We hypothesized that decreased soil pH and nutrient availability would reduce invasive biomass and enhance diversity. We show that acidification reduced invasive biomass by 71%, with acidification negatively affecting invasives while sparing natives. Maintaining nutrient‐poor soil conditions can help to control invasive grasses in restoration projects, as fertilizer application can favor invasive species establishment. Soil acidification effectiveness depends on local nutrient levels. Areas with high soil cation content may require larger amendment quantities. Restoration strategies in nutrient‐poor ecosystems should aim recovering historical soil conditions to control invasives growth and support slow‐growing native plants.

Extensive woody encroachment altering Angolan miombo woodlands despite cropland expansion and frequent fires

AbstractWoody encroachment (WE) and agricultural expansion are widespread in tropical savannas, where they threaten biodiversity and ecosystem function. In Africa's largest savanna, the miombo woodlands, cropland expansion is expected to cause extensive habitat loss over the next 30 years. Meanwhile, widespread WE is altering the remaining untransformed vegetation. Quantifying the extent of both processes in the Angolan miombo woodlands (~570,000 km2) has been challenging due to limited infrastructure, a history of conflict, and widespread landmines. Here, we analyze spectral satellite imagery to investigate the extent of WE and cropland expansion in the Angolan miombo woodlands since 1990. We asses WE using two complementary metrics: multi‐decade canopy greenness trends and conversion from grassland to woodland. We also examine whether WE trends are driven by landscape fragmentation and decreasing fire frequency. We found that from 1990 to 2020, 34.1% of the Angolan miombo woodlands experienced significant WE or was converted to cropland, while open grassy vegetation declined by 62%. WE advanced rapidly even in areas experiencing extraordinarily high burn frequencies and was not adequately explained by changing temperature or precipitation. WE was concentrated far from the agricultural frontier, in remote areas with low population densities. These results challenge the hypothesis that human‐altered fire regimes are the primary driver of WE in mesic savannas. The results will help decision‐makers conserve the miombo woodlands' biodiversity and ecosystem services, by highlighting that strategies to slow habitat loss must address WE and cropland expansion together.

Grassland Birds of Brazilian Cerrado: Population Trends and Conservation Challenges

Grassland ecosystems, characterized by open landscapes dominated by grasses, encompass diverse formations influenced by geological, climatic, and anthropogenic factors. These environments play a pivotal role in global biodiversity, carbon cycling, and ecosystem services. Due to the worldwide loss and degradation of these habitats, grassland birds are experiencing an unprecedented population decline. This work aims to supply an in-depth exploration of the conservation status of Cerrado grassland birds, including their population trends, protective measures, and primary threats within this bird group. Through an exhaustive literature review, conference of endangered species databases, and field data of grassland birds gathered by us, we compiled a comprehensive dataset detailing the trends, threats, and distribution of Cerrado grassland birds. The Cerrado, the world's largest savanna and Brazil's second-largest biome, accommodates 116 bird species specialized in grassland formations, including 13 endemics. Significantly, a notable proportion (26%) of endangered bird species in the Cerrado are strongly associated with grasslands. The primary threats faced by this group encompass habitat loss and degradation, the proliferation of exotic grass species, and the recurrent incidence of wildfires. Upon analyzing population trends, a concerning 37% of Cerrado grassland birds show declining numbers, with inadequate representation in existing protected areas. While grasslands hold global significance, conservation endeavors often give precedence to tropical forests. The preservation of central Brazil's grassland formations assumes utmost importance in safeguarding the abundant biodiversity of the Cerrado. These formations function as pivotal habitats for endangered and declining bird species, underscoring the pressing need to develop conservation strategies attuned to the unique challenges posed by grassland environments.

Genomic signatures of ecological divergence between savanna and forest populations of a Neotropical tree.

In eastern Neotropical South America, the Cerrado, a large savanna vegetation, and the Atlantic Forest harbour high biodiversity levels, and their habitats are rather different from each other. The biomes have intrinsic evolutionary relationships, with high lineage exchange that can be attributed, in part, to a large contact zone between them. The genomic study of ecotypes, i.e. populations adapted to divergent habitats, can be a model to study the genomic signatures of ecological divergence. Here, we investigated two ecotypes of the tree Plathymenia reticulata, one from the Cerrado and the other from the Atlantic Forest, which have a hybrid zone in the ecotonal zone of Atlantic Forest-Cerrado. The ecotypes were sampled in the two biomes and their ecotone. The evolutionary history of the divergence of the species was analysed with double-digest restriction site-associated DNA sequencing. The genetic structure and the genotypic composition of the hybrid zone were determined. Genotype-association analyses were performed, and the loci under putative selection and their functions were investigated. High divergence between the two ecotypes was found, and only early-generation hybrids were found in the hybrid zone, suggesting a partial reproductive barrier. Ancient introgression between the Cerrado and Atlantic Forest was not detected. The soil and climate were associated with genetic divergence in Plathymenia ecotypes and outlier loci were found to be associated with the stress response, with stomatal and root development and with reproduction. The high genomic, ecological and morphophysiological divergence between ecotypes, coupled with partial reproductive isolation, indicate that the ecotypes represent two species and should be managed as different evolutionary lineages. We advise that the forest species should be re-evaluated and restated as vulnerable. Our results provide insights into the genomic mechanisms underlying the diversification of species across savanna and forest habitats and the evolutionary forces acting in the species diversification in the Neotropics.

Frugivory and seed dispersal in the Cerrado: Network structure and defaunation effects

AbstractSeed dispersal is a fundamental process that is highly threatened by the rapid decline of large‐bodied frugivores worldwide. The Brazilian Cerrado, the largest savanna in the world, represents an ideal site for investigating seed dispersal because of its biodiversity, environmental challenges, and knowledge shortfalls. We performed a systematic literature review to analyze the seed dispersal network in the Cerrado and the potential impacts of the defaunation of large‐bodied frugivores on it. We considered network metrics, calculated the defaunation index of the frugivore assemblage, and compared traits among different fruit‐sized plants and their respective dispersers in the network. We retrieved 1565 interactions involving 193 plant species and 270 animal species. Results show that the Cerrado seed dispersal network is slightly nested and considerably modular, dominated by small‐ to medium‐sized generalist species, such as passerines, marsupials, and mesocarnivores. Nonetheless, large‐bodied frugivores like the lowland tapir have a key role in the network due to their great foraging and network integration capacity. The Cerrado frugivore assemblage is moderately defaunated, with possible effects in its interactions with large‐fruited plants. The Cerrado's defaunation and functional loss of large vertebrates deserve urgent attention to further understand the impacts on seed dispersal mechanisms and ecosystem functioning.

The impact of bushfires on animal abundance and diversity across land tenures in Miombo woodlands, Tanzania

Abstract. Matimbwi L, Madoffe SS. 2022. The impact of bushfires on animal abundance and diversity across land tenures in Miombo woodlands, Tanzania. Asian J For 6: 43-51. Southern Africa is dominated by Miombo forests (woodlands), the world's largest savanna. The purpose of this research was to examine how bushfires affect mammalian populations in Miombo woodlands under various forest tenure systems. The data was gathered through household questionnaires, a probing question checklist for key informants, participant observation, Participatory Rural Appraisal (PRA) methods, and a field inventory. We enlisted the aid of the local communities in our analysis of the PRA data we collected. Quantitative and qualitative data and information were subjected to content and structural-functional analysis. Quantitative data was examined using Statistical Package for the Social Sciences (SPSS) software. Microsoft Excel was used to examine inventory data on animal stocks. The average number of mammals collected from each forest tenure system was compared using Analysis of Variance (ANOVA) to see if there were statistically significant variations. The variety of mammal species in various forest tenure systems was measured using the Shannon-Wiener Index (H). Based on the findings, agricultural activities (44.5%), charcoal production (21.1%), and wildlife hunting (18.9%) accounted for the vast majority of bushfires in Miombo woods. It was thought that illegal logging and honey collection were the only contributing factors. Mammal populations tend to be most significant in Central Governmental Forest Reserves, then in those of the Local Government, and finally in those of the Village Government. Mildly burned sections in the Central Governmental Forest Reserve had a diversity index of 3.2. In contrast, those in the Local Government Forest Reserve and the Village Forest Reserve had indices of 2.0. There was little difference in the diversity index values of the Central Governmental Forest Reserve (2.0) and the Village Forest Reserve (2.0) for moderately burned blocks and the Local Government Forest Reserve (1.6) for unburned blocks. The Central Governmental Forest Reserve had a diversity value of 1.5 for the severely burned blocks, the Village Governmental Forest Reserve had a value of 1.4, and the Local Government Forest Reserve had a value of 1.2. Like other mammals with a low fire escape rate, bushfires hit the rock hyrax particularly hard. As a result, it is suggested that the current management regimes of Local Government Authorities be strengthened to ensure enhanced local community participation with more effective law enforcement measures to save the woods from deterioration. Similarly, communities should be given access to financing and encouragement to pursue income-generating activities to lessen their reliance on Miombo woodlands.

New patterns of the tree beta diversity and its determinants in the largest savanna and wetland biomes of South America

Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation. Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America. We also evaluated the contribution of three sets of determinants of the occurrence- and abundance-based subregions. We compiled data on tree species composition from 894 local assemblages based on species occurrences, and from 658 local assemblages based on species abundances. We used an unconstrained community-level modelling approach and clustering techniques to identify and map tree subregions for the occurrence and the abundance data sets, separately. Hierarchical clustering analyses were conducted to investigate floristic affinities between the subregions and to map broader floristic regions. We used multinomial logistic regression models, deviance partitioning, and rank-sum tests to assess the main subregion correlates. We identified 18 occurrence- and four abundance-based subregions in the Cerrado-Pantanal. The hierarchical classifications grouped the occurrence-based subregions into nine floristic zones and abundance-based subregions into two broad floristic zones. Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance data sets. The occurrence- and abundance-based subregions are complementary approaches to disentangle macroecological patterns and to plan conservation efforts in the Cerrado and the Pantanal. Our findings based on occurrence data revealed more complex and interdigitated boundaries between subregions of tree species than previously reported. The environment, historical stability, and human effects act in a synergetic way on the distribution of the subregions. Finally, the relevance of contemporary environmental factors to the subregion patterns we found alert us to the profound impact global warming may have on the spatial organization of the Cerrado-Pantanal tree flora.

Night on Earth

Night on Earth

Agricultural expansion in African savannas: effects on diversity and composition of trees and mammals

Land use change (LUC) is the leading cause of biodiversity loss worldwide. However, the global understanding of LUC's impact on biodiversity is mainly based on comparisons of land use endpoints (habitat vs non-habitat) in forest ecosystems. Hence, it may not generalise to savannas, which are ecologically distinct from forests, as they are inherently patchy, and disturbance adapted. Endpoint comparisons also cannot inform the management of intermediate mosaic landscapes. We aim to address these gaps by investigating species- and community-level responses of mammals and trees along a gradient of small scale agricultural expansion in the miombo woodlands of northern Mozambique. Thus, the case study represents the most common pathway of LUC and biodiversity change in the world's largest savanna. Tree abundance, mammal occupancy, and tree- and mammal-species richness showed a non-linear relationship with agricultural expansion (characterised by the Land Division Index, LDI). These occurrence and diversity metrics increased at intermediate LDI (0.3 to 0.7), started decreasing beyond LDI > 0.7, and underwent high levels of decline at extreme levels of agricultural expansion (LDI > 0.9). Despite similarities in species richness responses, the two taxonomic groups showed contrasting β-diversity patterns in response to increasing LDI: increased dissimilarity among tree communities (heterogenisation) and high similarity among mammals (homogenisation). Our analysis along a gradient of landscape-scale land use intensification allows a novel understanding of the impacts of different levels of land conversion, which can help guide land use and restoration policy. Biodiversity loss in this miombo landscape was lower than would be inferred from existing global syntheses of biodiversity-land use relations for Africa or the tropics, probably because such syntheses take a fully converted landscape as the endpoint. As, currently, most African savanna landscapes are a mosaic of savanna habitats and small scale agriculture, biodiversity loss is probably lower than in current global estimates, albeit with a trend towards further conversion. However, at extreme levels of land use change (LDI > 0.9 or < 15% habitat cover) miombo biodiversity appears to be more sensitive to LUC than inferred from the meta-analyses. To mitigate the worst effects of land use on biodiversity, our results suggest that miombo landscapes should retain > 25% habitat cover and avoid LDI > 0.75—after which species richness of both groups begin to decline. Our findings indicate that tree diversity may be easier to restore from natural restoration than mammal diversity, which became spatially homogeneous.

Ostrich population densities and temporal dynamics in coupled social-ecological systems: Suitable indicators for the ecological effectiveness of protected areas?

Assessing the ecological effectiveness of protected areas is a high priority in conservation biology and requires suitable indicators. Instead of using multiple species, single species can potentially be used as indicators to assess if conservation efforts are effective in maintaining species over time. Here, we assessed the suitability of ostrich (Struthio camelus massaicus) population densities and trends over time as indicators for the ecological effectiveness of four study areas (two national parks, a pastoral area, and a game-controlled area with manifold human impacts) in the Tarangire-Manyara ecosystem of northern Tanzania. Based on road transect surveys from 2011 to 2019, we estimated area- and season-specific population densities in a distance sampling framework and estimated temporal changes using generalized linear mixed models. Ostrich population densities and population trends over time were not associated with formal protection status. Ostriches in one national park occurred at highest densities and were constant over time, while densities were low in another national park and apparently declined over time. Ostriches in the pastoral area had the second-highest mean population density, while remaining constant over time. The study area with the highest human impact had lowest ostrich densities and a seemingly declining trend over time. Ostrich densities were positively correlated with time-matched population density estimates of nine out of ten ungulate species in the same study areas, suggesting that ostrich population densities broadly reflect those of large savanna mammals in this ecosystem. However, site-specific ostrich population trends over time were not closely correlated with trends of common large mammal species. Therefore, ostrich population densities appear as suitable management indicators to assess the broad ecological effectiveness of protected areas. However, ostrich population trajectories do not appear suitable as indicator surrogate to monitor trends of mammal populations over time.

Analysis of Economic Efficiency and its Determinants in Millet Based Production Systems in the Derived Savanna Zone of Nigeria

Millet is grown in the large savanna region of Nigeria mostly in a system of intercropping with other crops. The study seeks to analyse the efficiencies of millet-based production pattern and its determining factors in the derived savanna zone of Nigeria. Data were collected from primary sources using a structured questionnaire administered to the selected 196 millet-based farmers. Input oriented Data Envelope Analysis (DEA) and Tobit regression model were used to achieve the aims of the research. The mean Technical Efficiency (TE) of the millet and sorghum (MS), millet-sorghum-groundnut and cowpea (MSGC), millet-sorghum and groundnut (MSG), millet-sorghum and cowpea (MSC) and sole millet (SM) were 40, 21, 38, 32 and 48 % respectively. This suggests that in the short run, there are gaps of 60, 79, 62, 68 and 52 % to increase the efficiency levels respectively. This may be through enhanced use of accessible production inputs. The mean Allocative Efficiency (AE) for the millet-based farmers was 0.56, 0.55, 0.67, 0.56 and 0.91 for MS, MSGC, MSG, MSC and SM respectively. The results revealed that estimates of factors that influence millet-based farmers’ systems have different degrees of statistical significance and where the level of significance is the same, the magnitude and direction were not the same. The numbers of millet-based farms operating under constant, increasing, and decreasing returns to scale were also estimated. The result of sensitivity analysis for an optimum plan for millet-based inputs used showed that land, seed, labour, fertilizer and agrochemicals are not limiting resources to obtain optimal farm plan. These results indicate the units needed to be decreased from various millet farms respectively for optimal production. More youths should be encouraged by the government and private organizations by providing them with necessary incentives to engage in farming to minimize inefficiency associated with older aged farmers.

Resprouting strategies of three native shrub Cerrado species from a morphoanatomical and chemical perspective

This study was carried out in a Cerrado (the largest savanna in the Neotropics) area where pine plantations, introduced in the 1970s, were removed by clear cutting of the trees and burning of the remaining material. After the removal and burning, some native shrub species resprouted. Since resprouting is dependent on buds that can be in the belowground bud-bearing (BBB) organs containing reserves, we selected three resprouting Myrtaceae species for analysis of morphology and anatomy of their BBB organs, to determine which compounds could be accumulated and to investigate the bud protection features. Standard histological techniques were used to analyse the BBB organs. The belowground bud bank at a depth of 10 cm was determined. Nonstructural carbohydrates, total phenolics, and flavonoids were quantified on the roots. The large size of BBB organs suggest that these species were present before plantation establishment and survived plantation management treatments. All species produced a large number of axillary buds. All BBB organs exhibited significant lignification and stored starch and phenolic compounds in the parenchyma cells. The protective features and the storage of reserves associated with the bud-bank allowed the survival and subsequent resprouting of these species, contributing to the regeneration of this disturbed area.

Tropical riparian forests in danger from large savanna wildfires

Abstract Tropical savannas are known for the fire‐prone ecosystems, yet, riparian evergreen forests are another important landscape feature. These forests usually remain safe from wildfires in the wet riparian zones. With global changes, large wildfires are now more frequent in savanna landscapes, exposing riparian forests to unprecedented impact. In 2017, a large wildfire spread across the Chapada dos Veadeiros National Park, an iconic UNESCO site in central Brazil, raising concerns about its impact on the fire‐sensitive ecosystems. By combining remote sensing analysis of Google Earth images (2003–2019) with detailed field information from 36 sites, we assessed wildfire impacts on riparian forests. For this, we measured the structure of trees, saplings and herbaceous plants, as well as topsoil variables. Since 2003, all riparian forests had canopy cover above 90%, but after 2017, canopy cover dropped to 20% in some forests, indicating large variation in wildfire damage. A closer look in the field revealed that, on average, the wildfire killed 52% of adult trees and 87% of tree saplings in flooded forests. In non‐flooded forests, impacts on adult trees were negligible, but fire killed 75% of tree saplings. Opportunistic vines and the invasive grass Melinis minutiflora were already present in severely disturbed flooded forests. In all forests, impacts on many ecosystem variables were related to canopy damage, a variable measurable from satellite. Overall, seasonally flooded riparian forests were the most severely impacted, possibly due to the relatively thinner barks of their trees. Synthesis and applications. Our findings reveal how riparian forests embedded in tropical savanna landscapes are in danger from large wildfires. The destruction of some forests has opened space for new plant species that may propel a shift to an alternative ecosystem state. Riparian forests are habitat of large savanna animals and their loss could affect entire trophic networks. Managing wildfires and invasive grasses locally is probably the best strategy to maintain riparian forests resilient. As wildfire regimes intensify in tropical savanna landscapes, our findings stress the need for an integrated management that considers riparian forests as a vulnerable element of the system.

Toward Operational Mapping of Woody Canopy Cover in Tropical Savannas Using Google Earth Engine

Savanna woody plants can store significant amounts of carbon while also providing numerous other ecological and socio-economic benefits. However, they are significantly under-represented in widely used tree cover datasets, due to mapping challenges presented by their complex landscapes, and the underestimation of woody plants by methods that exclude short stature trees and shrubs. In this study, we describe a Google Earth Engine (GEE) application and present test case results for mapping percent woody canopy cover (%WCC) over a large savanna area. Relevant predictors of %WCC include information derived from radar backscatter (Sentinel-1) and optical reflectance (Sentinel-2), which are used in conjunction with plot-level %WCC measurements to train and evaluate random forest models. We can predict %WCC at 40m pixel resolution for the full extent of Senegal with a root mean square error of ~8% (based on independent sample evaluation). Further examination of model results provides insights into method stability and potential generalizability. Annual median radar backscatter intensity is determined to be the most important satellite-based predictor of %WCC in savannas, likely due to its relatively strong response to non-leaf structural components of small woody plants which remain mostly constant across the wet and dry season. However, the best performing model combines radar backscatter metrics with optical reflectance indices that serve as proxies for greenness, dry biomass, burn incidence, plant water content, chlorophyll content, and seasonality. The primary use of GEE in the methodology makes it scalable and replicable by end-users with limited infrastructure for processing large remote sensing data.

Grazing by large savanna herbivores indirectly alters ant diversity and promotes resource monopolisation.

In savannas, grazing is an important disturbance that modifies the grass layer structure and composition. Habitat structural complexity influences species diversity and assemblage functioning. By using a combination of natural sites and manipulated experiments, we explored how habitat structure (grazing lawns and adjacent bunch grass) affects ant diversity and foraging behaviour, specifically the efficiency of resource acquisition, resource monopolisation and ant body size. We found that in the natural sites there was no difference in the amount of time ants took to locate resources, but in the manipulated experiments, ants were faster at locating resources and were more abundant in the simple treatments than in the more complex treatments. Ant body size was only affected by the manipulated experiments, with smaller ants found in the more complex treatments. In both the grazing lawn and bunch grass habitats there were differences in assemblage patterns of ants discovering resources and those dominating them. Seasonality, which was predicted to affect the speed at which ants discovered resources and the intensity of resource monopolisation, also played a role. We show that ants in winter monopolised more baits and discovered resources at a slower rate, but only at certain times within the experiment. Grazing in conjunction with season thus had a significant effect on ant diversity and foraging behaviour, with dominant ants promoted where habitat complexity was simplified when temperatures were low. Our results indicate that structural complexity plays a major role in determining ant assemblage structure and function in African savannas.

Evolving fire management strategies and their impact on the occurrence and spatial extent of unplanned wildfires in a large African savanna park

Savannas cover approximately 20 % of the global land surface. In African savannas, fire is an important agent for controlling these ecosystems. Kruger National Park (KNP) is a large African savanna park which has implemented a variety of fire management strategies over the years. Using KNP’s recorded fire history (from 1941-2017), we examined the occurrence and spatial extent of accidental wildfires in KNP in relation to adaptations in the fire management strategies over time. From 1941 to 2017 fires were a regular, almost annual occurrence in KNP. However, fuel loads accumulate over time when fires are extinguished or controlled burning in these landscapes is prevented, and the result is a substantial amount of combustible material to support large unplanned wildfires. Therefore, fire management strategies influence the occurrence and spatial extent of unplanned wildfires in African savannas. Prescribed burning is a critical management tool which should be used in fire-prone landscapes, however, research is needed to determine the appropriate fire regime needed to manage a fire-driven system.

Carbon losses from deforestation and widespread degradation offset by extensive growth in African woodlands

Land use carbon fluxes are major uncertainties in the global carbon cycle. This is because carbon stocks, and the extent of deforestation, degradation and biomass growth remain poorly resolved, particularly in the densely populated savannas which dominate the tropics. Here we quantify changes in aboveground woody carbon stocks from 2007–2010 in the world’s largest savanna—the southern African woodlands. Degradation is widespread, affecting 17.0% of the wooded area, and is the source of 55% of biomass loss (−0.075 PgC yr−1). Deforestation losses are lower (−0.038 PgC yr−1), despite deforestation rates being 5× greater than existing estimates. Gross carbon losses are therefore 3–6x higher than previously thought. Biomass gains occurred in 48% of the region and totalled +0.12 PgC yr−1. Region-wide stocks are therefore stable at ~5.5 PgC. We show that land cover in African woodlands is highly dynamic with globally high rates of degradation and deforestation, but also extensive regrowth.

Ecosystem management can mitigate vegetation shifts induced by climate change in West Africa

The welfare of people in the tropics and sub-tropics strongly depends on goods and services that savanna ecosystems supply, such as food and livestock production, fuel wood, and climate regulation. Flows of these services are strongly influenced by climate, land use and their interactions. Savannas cover c. 20% of the Earth's land surface and changes in the structure and dynamics of savanna vegetation may strongly influence local people's living conditions, as well as the climate system and global biogeochemical cycles. In this study, we use a dynamic vegetation model, the aDGVM, to explore interactive effects of climate and land use on the vegetation structure and distribution of West African savannas under current and anticipated future environmental conditions. We parameterized the model for West African savannas and extended it by including sub-models to simulate fire management, grazing, and wood cutting. The model projects that under future climate without human land use impacts, large savanna areas would shift toward more wood dominated vegetation due to CO2 fertilization effects, increased water use efficiency and decreased fire activity. However, land use activities could maintain desired vegetation states that ensure fluxes of important ecosystem services, even under anticipated future conditions. Ecosystem management can mitigate climate change impacts on vegetation and delay or avoid undesired vegetation shifts. The results highlight the effects of land use on the future distribution and dynamics of savannas. The identification of management strategies is essential to maintain important ecosystem services under future conditions in savannas worldwide.

A Cerrado bird community in the northernmost portion of northeastern Brazil - recommendations for conservation

he Cerrado is the largest savanna in South America and it is rich in fauna and flora and considered a biodiversity hotspot. Its contact with the surrounding Amazon, Atlantic Forest and Caatinga is irregular, forming large diffuse ecotones in some regions and disjointed patches in others. The Cerrado patches located in the Amazon are relatively studied, but little is known about those in the Atlantic Forest and Caatinga. This article presents information on the composition of a bird community in a savanna formation on the coast of the northernmost portion of northeast Brazil (5o23'25S / 35o30'25W). This site was visited 17 times between October 2006 and August 2013. The total richness was 87 species distributed into 32 families. The following Cerrado endemics were recorded: Charitospiza eucosma and Porphyrospiza caerulescens. Other species recorded associated mainly with the Cerrado biome were Heliactin bilophus, Cypsnagra hirundinacea and Coryphaspiza melanotis. Some vulnerable and near threatened species were also recorded for the first time in the northernmost portion of northeastern Brazil, with some of these more than 1,000 km from their previously known localities. The results broaden the knowledge on the distribution of various species, in addition to providing information on seasonality and reproduction of others and revealing an overall lack of information on the composition of avian communities in little studied areas of Brazil.

Topographical units and soil types prove more efficient for vegetation sample site placement than Land Type units in semi-arid savanna, North West province, South Africa

Land Type mapping units were used to stratify the Heritage Park corridor, in the North West province, South Africa, into eight Land Type units prior to placing 109 floristic sample sites. At each site, species composition and relative frequency data were recorded for the herbaceous and woody layer. The floristic data (species presence at each site) were grouped into Land Types, topographical units and broad soil types. Each group was analysed independently using multivariate detrended correspondence analysis (DCA) and the mean similarity test. The floristic data in each Land Type showed a 42% range of similarity and considerable overlap of polygons on the DCA diagram. However, floristic data classed in topographical units reduced the range of percentage similarity to 29%. Before the Land Types map could be completely dismissed, the broader soil descriptions were compared and the percentage similarity of the four different soil forms was 28%. The detailed combination of terrain types, soil forms and climate zones constituting Land Type units was less suitable for the stratification of vegetation units than either of the broader soil types or topographic units when stratifying large savanna areas for vegetation surveys.