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Background: Animal movement arises from complex interactions between animals and their heterogeneous environment. To better understand the movement process, it can be divided into behavioural, temporal and spatial components. Although methods exist to address those various components, it remains challenging to integrate them in a single movement analysis. Methods: We present an analytic workflow that integrates the behavioural, temporal and spatial components of the movement process and their interactions, which also allows for the assessment of the relative importance of those components. We construct a daily cyclic covariate to represent temporally cyclic movement patterns, such as diel variation in activity, and combine the three components in a multi-modal Hidden Markov Model framework using existing methods and R functions. We compare the trends and statistical fits of models that include or exclude any of the behavioural, spatial and temporal components, and perform variance partitioning on the model predictions that included all components to assess their relative importance to the movement process, both in isolation and in interaction. Results: We apply our workflow to a case study on the movements of plains zebra, blue wildebeest and eland antelope in a South African reserve. Behavioural modes impacted movement the most, followed by diel rhythms and then the spatial environment (viz. tree cover and terrain slope). Interactions between the components often explained more of the movement variation than the marginal effect of the spatial environment did on its own. Omitting components from the analysis led either to the inability to detect relationships between input and response variables, resulting in overgeneralisations when drawing conclusions about the movement process, or to detections of questionable relationships that appeared to be spurious. Conclusions: Our analytic workflow can be used to integrate the behavioural, temporal and spatial components of the movement process and quantify their relative contributions, thereby preventing incomplete or overly generic ecological interpretations. We demonstrate that understanding the drivers of animal movement, and ultimately the ecological phenomena that emerge from it, critically depends on considering the various components of the movement process, and especially the interactions between them. [ABSTRACT FROM AUTHOR]

Abstract Background Animal movement arises from complex interactions between animals and their heterogeneous environment. To better understand the movement process, it can be divided into behavioural, temporal and spatial components. Although methods exist to address those various components, it remains challenging to integrate them in a single movement analysis. Methods We present an analytic workflow that integrates the behavioural, temporal and spatial components of the movement process and their interactions, which also allows for the assessment of the relative importance of those components. We construct a daily cyclic covariate to represent temporally cyclic movement patterns, such as diel variation in activity, and combine the three components in a multi-modal Hidden Markov Model framework using existing methods and R functions. We compare the trends and statistical fits of models that include or exclude any of the behavioural, spatial and temporal components, and perform variance partitioning on the model predictions that included all components to assess their relative importance to the movement process, both in isolation and in interaction. Results We apply our workflow to a case study on the movements of plains zebra, blue wildebeest and eland antelope in a South African reserve. Behavioural modes impacted movement the most, followed by diel rhythms and then the spatial environment (viz. tree cover and terrain slope). Interactions between the components often explained more of the movement variation than the marginal effect of the spatial environment did on its own. Omitting components from the analysis led either to the inability to detect relationships between input and response variables, resulting in overgeneralisations when drawing conclusions about the movement process, or to detections of questionable relationships that appeared to be spurious. Conclusions Our analytic workflow can be used to integrate the behavioural, temporal and spatial components of the movement process and quantify their relative contributions, thereby preventing incomplete or overly generic ecological interpretations. We demonstrate that understanding the drivers of animal movement, and ultimately the ecological phenomena that emerge from it, critically depends on considering the various components of the movement process, and especially the interactions between them.

This study aims to monitor the implications of climate change on savanna ecosystem drought using time series data from the Landsat 8 sensor, spanning from 2013 to 2022. We employed a remote sensing computational approach with the semi-automatic classification plugin (SCP) in the open-source QGIS software. Specifically, we utilized channels from the operational land imager (OLI), including Band 4 Red (0.636-0.673 µm) and Band 5 Near-Infrared (0.851-0.879 µm), as well as Thermal Infrared Sensor (TIRS) channels Band 10 TIRS-1 (10.60-11.19 µm) and Band 11 TIRS-2 (11.50-12.51 µm). These channels were used to calculate the vegetation health index (VHI) using the raster calculator, followed by data reclassification with specific thresholds to compare drought-affected areas. Our findings reveal a significant impact of climate change on savanna ecosystem drought over the decade, with the most extreme conditions observed in 2015 and 2019, where drought coverage reached 42.74% and 26.58%, respectively. Other years exhibited relatively low drought dynamics, affecting less than 3% of the area. This period aligns with the el niño-southern oscillation (ENSO) phenomenon, particularly the transition from El Niño to La Niña, known to cause global weather variations, and significantly influenced by the positive phase of the Indian Ocean dipole (IOD). The novelty of this research lies in two main aspects: firstly, the use of Landsat satellite sensors for this specific region has not been extensively studied before; secondly, the discovered impacts of drought in relation to global climate change phenomena are particularly noteworthy. A limitation of this study is the relatively short investigation period of just one decade, which does not fully capture the long-term impacts of climate change. Future research is recommended to utilize imagery with higher temporal resolution over extended periods to better represent extreme climate events and derive drought patterns over durations exceeding one decade. [ABSTRACT FROM AUTHOR]

Plant transpiration is a key component of the hydrological cycle that moves water from the soil through plants to the atmosphere and is largely determined by environmental conditions. The challenges of highly variable climatic conditions and water scarcity in the semi‐arid savannas of southern Africa drive trees to exhibit different water use strategies.An additional challenge for savanna trees arises from the browsing of large mammals, and its potential impact on transpiration has largely been overlooked.To assess water use strategies and the impact of browsing on transpiration in three common savanna woody species (Colophospermum mopane, Catophractes alexandri, Senegalia mellifera), we conducted an extensive field experiment in a wildlife reserve in Namibia. We established a browsing gradient ranging from 0% to 100% leaf removal to disentangle complex relationships, and we measured sap flow representing whole‐tree transpiration, stomatal conductance as a proxy for leaf level transpiration, and environmental factors including soil moisture, solar radiation, air temperature and air humidity.We discovered a unimodal relationship between browsing intensity and sap flow, consistent across all species, and peaking at low to moderate browsing levels equivalent to approximately 30% leaf removal. This universal pattern is remarkable since we found water use strategies to differ among species: Colophospermum mopane and C. alexandri exhibit a water‐saving behaviour to reduce water loss under unfavourable conditions while S. mellifera demonstrates water‐spending characteristics.The deviation from a negative linear effect of browsing does not meet the functional expectation when browsing is translated into a simple leaf area reduction. Instead, it can be attributed to stomatal adjustments that partially compensate for transpiratory surface loss. We propose that this conceptual mechanism can be generalised to other woody species and various ecosystems. In addition, common transpiration models relying solely on leaf area indices and abiotic factors can be improved by including a non‐linear relationship to reproduce the effect of browsing accurately.Our findings highlight the role of herbivores in shaping the connection between the Earth's spheres and improve our understanding of ecohydrological and vegetation dynamics in Southern African savannas. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The yield of cowpea varieties is affected by environmental variability. Hence, candidate varieties must be tested for yield stability before release. This study assessed the impacts of genotypes, environments, and their interaction on the performance of elite cowpea lines for key adaptive, grain yield, and associated traits across different locations. A total of 42 elite genotypes were evaluated in five Nigerian environments, representing various savanna ecologies, during the 2021 growing season. The experimental design employed was an alpha lattice arrangement, with each genotype replicated three times. The results revealed significant differences among genotypes, environments, and genotype-by-environment interaction (G × E) for most traits, including days to maturity, 100-seed weight, and grain yield. The genotype and genotype-by-environment interaction (GGE) biplot showed G21 (IT14K-2111-2) and G25 (IT15K-2386-1) as the most stable genotypes across the five environments, G41 (IT11K-61-82) was best adapted to Ibadan and Shika, G5 (245-1) was best adapted to Bagauda and Gumel, and G30 (IT16K-2365-1) was best adapted to Bauchi. G21 (IT14K-2111-2) and G25 (IT15K-2386-1) could be recommended across the five test environments, whereas G41 (IT11K-61-82), G30 (IT16K-2365-1), and G5 (245-1) were specific to the adapted environments. [ABSTRACT FROM AUTHOR]

Allometric equations are the most common way of assessing Aboveground biomass (AGB) but few exist for savanna ecosystems. The need for the accurate estimation of AGB has triggered an increase in the amount of research towards the 3D quantification of tree architecture through Terrestrial Laser Scanning (TLS). Quantitative Structure Models (QSMs) of trees have been described as the most accurate way. However, the accuracy of using QSMs has yet to be established for the savanna. We implemented a non-destructive method based on TLS and QSMs. Leaf-off multi scan TLS point clouds were acquired in 2015 in Kruger National Park, South Africa using a Riegl VZ1000. The 3D data covered 80.8 ha with an average point density of 315.3 points/m2. Individual tree segmentation was applied using the comparative shortest-path algorithm, resulting in 1000 trees. As 31 trees failed to be reconstructed, we reconstructed optimized QSMs for 969 trees and the computed tree volume was converted to AGB using a wood density of 0.9. The TLS-derived AGB was compared with AGB from three allometric equations. The best modelling results had an RMSE of 348.75 kg (mean = 416.4 kg) and a Concordance Correlation Coefficient (CCC) of 0.91. Optimized QSMs and model repetition gave robust estimates as given by the low coefficient of variation (CoV = 19.9% to 27.5%). The limitations of allometric equations can be addressed by the application of QSMs on high-density TLS data. Our study shows that the AGB of savanna vegetation can be modelled using QSMs and TLS point clouds. The results of this study are key in understanding savanna ecology, given its complex and dynamic nature. [ABSTRACT FROM AUTHOR]

In this study, we assessed the co-occurrence influence of Hyptis suaveolens and Urena lobata on native plant species and soil properties in a guinea savanna vegetation in Nigeria. We sampled 120 plots of 10 x 10 m² with 30 plots each in sites invaded by H. suaveolens, U. lobata, mixed site and in sites with none of the species (control). A sparse partial least square discriminant analysis was used to assess the effect of invasive plant treatments on the plant diversity and soil properties, whereas the relationships between the soil properties, plant diversity and invasive species treatments were assessed using the canonical correspondence analysis. The indices of diversity of the control were significantly higher than all the other treatments (p < 0.001) with the mixed site having the lowest. There were significant differences in phosphorus, calcium, aluminium, soil alkalinity and diversity indices among the treatments. The results also indicated that the diversity indices and some soil properties were negatively associated with the mixed site. The negative impacts on the native diversity and change in the soil properties caused by the co-invasion of these two plants are more additive than non-additive. Therefore, priority should be placed on the management of co-invaded sites. [ABSTRACT FROM AUTHOR]

The national food security policy attained through food self-sufficiency is artificial because it does not reflect the actual situation. This policy cannot consolidate various local food resources to serve as the foundation of inclusive national and regional food security. Instead, it tends to rely on exclusive and uniform food security, specifically rice. This contrasts with the geographical reality of Indonesia, which is ecologically endowed with abundant local food resources. This study seeks to explain why local food is neglected in national and regional food security policy frameworks and strategies, although it is acknowledged at the level of ideas and regulations but difficult to implement at the level of practice. This case study was conducted through a series of observations and in-depth interviews with regional policymakers and agricultural communities based on generational differences between those aged 60 and older and those aged 60 and younger. Using the Habitus-Bourdieu analysis, this study discovered that the green revolution policy led to the formation of a collective habitus at the state level, which was then institutionalized in various structural policies of the central and local government, resulting in the formation of an individual habitus at the community level. This habitus that transforms cultivation and food consumption patterns to prioritize rice and marginalizes local foods has created food insecurity, particularly in Savanna ecological regions like Sumba.

Abstract Striga hermonthica is fast spreading in the Nigerian savanna and is predicted to encroach into the rainforest part of the country soon. S. hermonthica seedbanks in savanna soils have continued to rise due to poor agronomic practices by smallholder farmers. Considering differences in soil, climate, and agronomic practices within the savanna endemic agroecology, the severity of the infestation of S. hermonthica has varied from one location to another. Hence, there is a need to model a site-specific management approach for S. hermonthica in Nigeria. This review aims to understand the state-of-the-art management of S. hermonthica in Nigeria’s upland rice fields and further harmonize potential management approaches. Based on studies conducted in Nigeria, reducing S. hermonthica parasitism over a long-term period in the Savanna ecology of Nigeria implies the rotation of upland rice with trap crops, and enhancement of nitrogen fertility in farmers’ fields, combined with the use of seed-treated resistant or tolerant cultivars. In practical terms, farmer’s-research engagement in the long term is pertinent to reduce the severity of S. hermonthica in threatened areas. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Less than half of the original two million km2 of the Brazilian Savanna natural vegetation, called the Cerrado Biome, remains standing. Given its climate and socio-biodiversity importance, more effective public policies are needed to protect the remaining natural areas. In this paper, we present the methodology and results of the DETER Cerrado, an early warning deforestation system within the Cerrado region. The findings support that DETER is effective in detecting a wider range of deforestation patch sizes, from the larger patches, heavily associated with agricultural expansion, to the smaller areas (>1 ha <10 ha). Nevertheless, 80% of the deforestation is concentrated in the 10-km radius zone from the DETER Alerts. This area was later detected by the Cerrado Deforestation Monitoring Project (PRODES), the system that accounts for the annual deforestation rate assessment, which highlights the capability of the DETER system to provide support to the surveillance of deforestation in the Cerrado. [ABSTRACT FROM AUTHOR]

The longleaf pine (Pinus palustris Mill.) and related ecosystem is an icon of the southeastern United States (US). Once covering an estimated 37 million ha from Texas to Florida to Virginia, the near-extirpation of, and subsequent restoration efforts for, the species has been well-documented over the past ca. 100 years. Although longleaf pine is one of the longest-lived tree species in the southeastern US—with documented ages of over 400 years—its use has not been reviewed in the field of dendrochronology. In this paper, we review the utility of longleaf pine tree-ring data within the applications of four primary, topical research areas: climatology and paleoclimate reconstruction, fire history, ecology, and archeology/cultural studies. Further, we highlight knowledge gaps in these topical areas, for which we introduce the Longleaf Tree-Ring Network (LTRN). The overarching purpose of the LTRN is to coalesce partners and data to expand the scientific use of longleaf pine tree-ring data across the southeastern US. As a first example of LTRN analytics, we show that the development of seasonwood chronologies (earlywood width, latewood width, and total width) enhances the utility of longleaf pine tree-ring data, indicating the value of these seasonwood metrics for future studies. We find that at 21 sites distributed across the species' range, latewood width chronologies outperform both their earlywood and total width counterparts in mean correlation coefficient (RBAR = 0.55, 0.46, 0.52, respectively). Strategic plans for increasing the utility of longleaf pine dendrochronology in the southeastern US include [1] saving remnant material (e.g., stumps, logs, and building construction timbers) from decay, extraction, and fire consumption to help extend tree-ring records, and [2] developing new chronologies in LTRN spatial gaps to facilitate broad-scale analyses of longleaf pine ecosystems within the context of the topical groups presented. [ABSTRACT FROM AUTHOR]

Megaherbivores play a critical role in the ecology of African savannas and grasslands. In addition, these systems are forecast to experience more frequent and severe droughts as a product of changes in the global climate. Thus, the continued conservation of megaherbivores and their associated ecosystems will require a better understanding of how megaherbivores respond to drought by shifting their movement, diet and social behaviour. We address this need by investigating the factors affecting changes in the abundance of common hippopotamus (Hippopotamus amphibius; hereafter: 'hippos') throughout the six major rivers of Kruger National Park, South Africa, during and following the severe drought of 2015/2016. Specifically, we aimed to understand the role of two environmental characteristics that have relevance to hippos and that changed in response to drought: vegetation condition and the extent of pooled surface water. In addition, we investigated the extent to which pre‐drought density affected changes in hippo abundance. Although vegetation and daytime refugia both appeared to influence pre‐drought hippo abundance, these factors were less important to the change in hippo abundance related to the drought. Instead, the response to drought was most strongly related to the pre‐drought abundance of hippos, where river segments supporting more than 50 individuals prior to the drought in 2015 decreased by more than half on average. Furthermore, we show that the degree of aggregation decreased from 2015 to 2016 because of the drought, but then began to increase again as the rains returned in 2017. Our results suggest that in addition to the large pools that support large aggregations of hippos in typical years, additional smaller pools are likely important for accommodating this drought‐induced dispersion. However, maintaining this distribution of pools will likely become more challenging as southern Africa's population and water demands increase. [ABSTRACT FROM AUTHOR]

The flexibility of UAV‐lidar remote sensing offers a myriad of new opportunities for savanna ecology, enabling researchers to measure vegetation structure at a variety of temporal and spatial scales. However, this flexibility also increases the number of customizable variables, such as flight altitude, pattern, and sensor parameters, that, when adjusted, can impact data quality as well as the applicability of a dataset to a specific research interest.To better understand the impacts that UAV flight patterns and sensor parameters have on vegetation metrics, we compared 7 lidar point clouds collected with a Riegl VUX − 1LR over a 300 × 300 m area in the Kruger National Park, South Africa. We varied the altitude (60 m above ground, 100 m, 180 m, and 300 m) and sampling pattern (slowing the flight speed, increasing the overlap between flightlines and flying a crosshatch pattern), and compared a variety of vertical vegetation metrics related to height and fractional cover.Comparing vegetation metrics from acquisitions with different flight patterns and sensor parameters, we found that both flight altitude and pattern had significant impacts on derived structure metrics, with variation in altitude causing the largest impacts. Flying higher resulted in lower point cloud heights, leading to a consistent downward trend in percentile height metrics and fractional cover. The magnitude and direction of these trends also varied depending on the vegetation type sampled (trees, shrubs or grasses), showing that the structure and composition of savanna vegetation can interact with the lidar signal and alter derived metrics. While there were statistically significant differences in metrics among acquisitions, the average differences were often on the order of a few centimetres or less, which shows great promise for future comparison studies.We discuss how these results apply in practice, explaining the potential trade‐offs of flying at higher altitudes and with alternate patterns. We highlight how flight and sensor parameters can be geared toward specific ecological applications and vegetation types, and we explore future opportunities for optimizing UAV‐lidar sampling designs in savannas. [ABSTRACT FROM AUTHOR]

Mitigating climate change requires us to constrain combustion in a double sense: decreasing both the use of fossil fuels and the flammability of the biosphere. Fire management by Indigenous peoples in Australia's northern savannas has been presented as a solution to offset the former and assist with the latter, leading to the foundation of a regional economy of projects generating 'premium' carbon credits on Indigenous lands. This article attends to the translational zone – predominantly made up of non‐Indigenous white professionals – that functions to configure the 'right story' of these credits across diverse epistemes and contexts. Following such commodities' interscalar connections, I suggest, helps illustrate the contingencies and contradictions produced by tradeable carbon, as individuals and organizations seek to maintain a niche within a changing climate and shifting global atmospheric relations. [ABSTRACT FROM AUTHOR]

The use of lime in reducing acidity, increasing nodulation and grain yield of field cowpea in Nigeria had not been determined. Hence, field experiments were conducted in 2020 and 2021 cropping seasons at the Landmark University, Omu-Aran, Nigeria. The study was undertaken to evaluate the effects of lime on soil chemical characteristics, growth, nodulation, and yield of cowpea on tropical-derived savanna. The treatments in each year consisted of five levels (0, 2.5, 5.0, 7.5 and 10 t/ha) of lime (CaCO3). The treatments were arranged in a RCBD and replicated three times. Findings showed that the application of lime improved soil chemical characteristics (pH, N, P, K, Ca, Na, Mg and CEC), growth, nodulation and yield of cowpea compared to the control. Lime application reduced acidity (H+Al3+) relative to the control. Lime increased the yield of cowpea from 0 to 2.5 t/ha after which there was a decrease. 2.5 t/ha lime increased pod weight of cowpea relative to the control by 51.2% in 2020 and 48.2% in 2021. 10 t/ha lime reduced pod weight of cowpea relative to the 2.5 t/ha by 237.62% in 2020 and 257.1% in 2021, the reduction in the yield of cowpea can best be explained by the presence of unfavourable soil pH conditions. Therefore, the optimum yield of the cowpea crop was achieved at 2.5 t/ha of lime for the agro ecological zone. [ABSTRACT FROM AUTHOR]

In Ghana’s Guinea savanna ecological zone, fuelwood is the primary source of energy for cooking and heating, but not much is known about the cultural importance of woody species as fuelwood. This study aimed to identify the plant species used as fuelwood and determine their cultural importance in Navrongo Forest District. Totally 246 households that rely on fuelwood as their primary energy source for heating and cooking were selected and interviewed using the free listing technique. The cultural importance index and relative importance index were used to determine the most culturally important species for fuelwood and preferences based on fuel attributes. A total of 32 plant species were identified to be used for fuelwood purposes; Anogeissus leiocarpa was identified to have the highest cultural importance index. The relative importance index revealed that Khaya senegalensis and Vitellaria paradoxa were the most important species based on their fuel attributes. Four species of conservation and economic importance (Khaya senegalensis, Parkia biglobosa, Pterocarpus erinaceus, and Vitellaria paradoxa) were identified as having high cultural importance and relative importance index for fuelwood purposes. It is recommended that species of conservation and economic importance should be evaluated due to the potential impact of their use as fuelwood on biodiversity and local economic development. [ABSTRACT FROM AUTHOR]

The study focused on the geospatial assessment of the physicochemical properties of soils at the Institute of Agricultural Research and Training, Ilora, Oyo State, Nigeria. Using the random survey method, 100 surfaces (0 to 20 cm) samples were collected and subjected to standard soil laboratory analyses. The variability of soil nutrients was examined using descriptive statistics, while spatial investigation and interpolation were achieved using the Ordinary krigging (OK) method. Crossvalidation accuracy with exponential and spherical models was used as a precision tool for the analyzed soil nutrients. Soil nutrient spatial trends were exponentially distributed across the area. Temporal predicted land surface temperature (LST), and soil-adjusted vegetation index (SAVI) were estimated through Landsat images of the years 2000 and 2020 using ArcGIS 10 software. The spectral variables - LST and SAVI were merged with soil nutrients to assess the maize suitability evaluation of the area. The LST and SAVI results revealed the qualitative differences in the studied area. The maize suitability showed that the studied soils ranged from moderately (85%), marginally (60%), and not suitable (< 40%). To increase the suitability of the soils for optimum maize production there is a need to enhance the limiting dominant factors such as undulating topography, rainfall, and erosion hazard. Hence, the study recommends the integration of geospatial techniques such as remote sensing covariate variables and exponential models as indispensable methods to assist farmers and policymakers in sustainable and precision agriculture. [ABSTRACT FROM AUTHOR]

In Oregon, an estimated 3% of the original Quercus garryana savanna remains seven generations after pioneer settlement. Consequently, the US Fish and Wildlife Service (USFWS), non-profit wildlife organizations, and Oregon state agencies and policy makers have put oak habitat, especially oak savanna restoration, among their highest priorities. "Oak savanna" is commonly defined as an area of large, open-growing oaks at a density of 4-5 trees per acre. Twenty-one years ago, Jolly Krautmann and I purchased a 400-acre farm that had an 85-acre oak savanna along the farm hillsides. Long neglected, it had become infested with many kinds of tall invasive weeds and vines. This paper summarizes specific measures that we have tried in oak savanna restoration. Despite initial failures, we feel we've succeeded in establishment of a stand of predominantly (65-85%) native grasses and wildflowers among the scattered open -growing oaks. Herein, we aim to offer insight and inspire others to engage in oak savanna restoration. [ABSTRACT FROM AUTHOR]

To assess the agronomic effects of sustainable okra production as impacted by goat manure (GM) and rice husk ash (RHA) on a community-based demonstration farm in Gombe State, field trials were carried out during the wet seasons of 2017 and 2018. The trails consisted of four levels of GM and RHA, each measuring 0.0, 5.0, 7.5, and 10.0 t ha-1 which were used on Kwadon's local cultivar of okra in a Randomized complete block design (RCBD) replicated four times. Findings revealed that days to 50% emergence and establishment count were not significantly (P>0.05) influenced by the application of GM and RHA, regardless of rates of application. Other growth-related indices were significantly (P<0.05) higher due to GM, such as plant height at 4, 5, and 6 WAS, number of leaves plant-1 at 4 WAS, and pod diameter. On the other hand, RHA significantly (P<0.05) increased plant height, the number of leaves plant-1 at 5 and 6 WAS, leaf area, shortened days to 50% flowering, and the number of pods plant-1 across the sampling periods and seasons. Similar to this, due to adequate mineralization of organic material through time and space, fresh okra's marketable weight increased in the 2018 season compared to the previous year. Thus, the application of 10.0 t ha-1 of both GM and RHA can be adopted in the production of okra in the study area to reduce greenhouse gas emissions resulting from the use of inorganic agrochemical inputs. [ABSTRACT FROM AUTHOR]

For over a century, deep roots have been assumed to allow trees to avoid competition with grasses (i.e., the two‐layer hypothesis). Yet, in part because it remains difficult to measure water uptake in the field, there has been a shift in savanna ecology away from the two‐layer hypothesis and towards alternative explanations of tree‐grass coexistence. Here, we combine hydrologic tracer experiments and soil water flow models to demonstrate how the distribution of active roots affects water uptake across a range of savanna conditions. Grass roots were shallower and provided pre‐emptive access to enough soil water to allow nearly continuous grass cover, but slightly deeper roots provided trees with more total water under most conditions. This 'some water now or more water later' tradeoff varied with precipitation amount, soil texture, and tree and grass relative root abundance in ways that helped explain tree and grass landscape abundance. [ABSTRACT FROM AUTHOR]

Bush encroachment is a habitat change phenomenon that threatens savanna and grassland ecosystems worldwide. In Africa, large carnivores in bush encroached landscapes must adjust to increasing woody plant cover and biomass, which could affect predation success at multiple stages through complex and context-dependent pathways. We highlight, interpret, and compare studies that assessed how bush encroachment or related habitat parameters affect the predation stages of large African carnivores. Bush encroachment may directly or indirectly affect predation success in various ways, including by: (1) altering habitat structure, which may affect hunting efficiency and prey accessibility; (2) changing prey abundance/distribution, with smaller species and browsers being potentially favoured; (3) influencing interference competition within the carnivore guild. For habitat or dietary specialists, and subordinate predators that are vulnerable to both top-down and bottom-up ecosystem effects, these alterations may be detrimental and eventually incur population fitness costs. As the threat of bush encroachment continues, future studies are required to assess indirect effects on competitive interactions within the large African carnivore guild to ensure that conservation efforts are focused. Additionally, to better understand the effects of bush encroachment across Africa, further research is necessary in affected areas as overall little attention has been devoted to the topic. [ABSTRACT FROM AUTHOR]

The rangelands of Africa have been subject to substantial changes. The changes in the savanna rangelands ecology were from different points of view. This study constructs the perceptions of Boorana pastoralists on historic changes in rangelands post-1992 based on the Gadaa timelines. The construction of pastoralist perceptions can make an immense contribution to comprehending the rate, trends, indicators, and impacts of rangeland degradation in Boorana rangelands. This study thus points out that pastoralists can better understand and describe rangeland conditions and factors associated with such changes in the Gadaa periods. The study was based on the data collected from 332 pastoralists using a survey questionnaire and qualitative data, and the results were analyzed using descriptions of responses and narrations of cases. The study revealed that the conditions of the Boorana rangelands have been deteriorating over time and rangeland degradation showed unprecedented growth trends, mainly attributed to vegetation, rangeland production, human, environmental, and climate change-related factors. The study also shows that the progressive degradation of rangeland resources has jeopardized rangeland production, livestock productivity, and human well-being in the Boorana rangeland system. The study suggests that the recognition and promotion of indigenous ecological knowledge of pastoralists could sustain the pastoralist community in arid and semiarid rangelands. It is, therefore, imperative to understand pastoralists' knowledge of rangeland ecology for sustainable management of rangeland resources. [ABSTRACT FROM AUTHOR]

African savannas are the last stronghold of diverse large-mammal communities, and a major focus of savanna ecology is to understand how these animals affect the relative abundance of trees and grasses. However, savannas support diverse plant life-forms, and human-induced changes in large-herbivore assemblages--declining wildlife populations and their displacement by livestock--may cause unexpected shifts in plant community composition. We investigated how herbivory affects the prevalence of lianas (woody vines) and their impact on trees in an East African savanna. Although scarce (<2% of tree canopy area) and defended by toxic latex, the dominant liana, Cynanchum viminale (Apocynaceae), was eaten by 15 wild large-herbivore species and was consumed in bulk by native browsers during experimental cafeteria trials. In contrast, domesticated ungulates rarely ate lianas. When we experimentally excluded all large herbivores for periods of 8 to 17 y (simulating extirpation), liana abundance increased dramatically, with up to 75% of trees infested. Piecewise exclusion of different-sized herbivores revealed functional complementarity among size classes in suppressing lianas. Liana infestation reduced tree growth and reproduction, but herbivores quickly cleared lianas from trees after the removal of 18-y-old exclosure fences (simulating rewilding). A simple model of liana contagion showed that, without herbivores, the long-term equilibrium could be either endemic (liana-tree coexistence) or an all-liana alternative stable state. We conclude that ongoing declines of wild large-herbivore populations will disrupt the structure and functioning of many African savannas in ways that have received little attention and that may not be mitigated by replacing wildlife with livestock. [ABSTRACT FROM AUTHOR]

Abstract Shrub encroachment has far‐reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning. We document the compositional change and potential drivers for a northern Namibian Combretum woodland transitioning into a Terminalia shrubland. We use a multiproxy record (pollen, sedimentary ancient DNA, biomarkers, compound‐specific carbon (δ13C) and deuterium (δD) isotopes, bulk carbon isotopes (δ13Corg), grain size, geochemical properties) from Lake Otjikoto at high taxonomical and temporal resolution. We provide evidence that state changes in semiarid environments may occur on a scale of one century and that transitions between stable states can span around 80 years and are characterized by a unique vegetation composition. We demonstrate that the current grass/woody ratio is exceptional for the last 170 years, as supported by n‐alkane distributions and the δ13C and δ13Corg records. Comparing vegetation records to environmental proxy data and census data, we infer a complex network of global and local drivers of vegetation change. While our δD record suggests physiological adaptations of woody species to higher atmospheric pCO2 concentration and drought, our vegetation records reflect the impact of broad‐scale logging for the mining industry, and the macrocharcoal record suggests a decrease in fire activity associated with the intensification of farming. Impact of selective grazing is reflected by changes in abundance and taxonomical composition of grasses and by an increase of nonpalatable and trampling‐resistant taxa. In addition, grain‐size and spore records suggest changes in the erodibility of soils because of reduced grass cover. Synthesis. We conclude that transitions to an encroached savanna state are supported by gradual environmental changes induced by management strategies, which affected the resilience of savanna ecosystems. In addition, feedback mechanisms that reflect the interplay between management legacies and climate change maintain the encroached state.

The late Pleistocene settlement of highland settings in mainland Southeast Asia by Homo sapiens has challenged our species's ability to occupy mountainous landscapes that acted as physical barriers to the expansion into lower-latitude Sunda islands during sea-level lowstands. Tham Lod Rockshelter in highland Pang Mapha (northwestern Thailand), dated between 34,000 and 12,000 years ago, has yielded evidence of Hoabinhian lithic assemblages and natural resource use by hunter-gatherer societies. To understand the process of early settlements of highland areas, we measured stable carbon and oxygen isotope compositions of Tham Lod human and faunal tooth enamel. Our assessment of the stable carbon isotope results suggests long-term opportunistic behavior among hunter-gatherers in foraging on a variety of food items in a mosaic environment and/or inhabiting an open forest edge during the terminal Pleistocene. This study reinforces the higher-latitude and -altitude extension of a forest-grassland mosaic ecosystem or savanna corridor (farther north into northwestern Thailand), which facilitated the dispersal of hunter-gatherers across mountainous areas and possibly allowed for consistency in a human subsistence strategy and Hoabinhian technology in the highlands of mainland Southeast Asia over a 20,000-year span near the end of the Pleistocene. [ABSTRACT FROM AUTHOR]

Vegetation dynamics in savannas are largely determined by water availability as well as soil nutrient dynamics. Species composition differs significantly from nutrient-rich soils to nutrient-poor soils, where the former is dominated by fine-leafed palatable woody species and the latter by broad-leafed and less palatable ones. Whilst this typically occurs at a landscape or catena scale, it is also interestingly observed at a localised and micro scale in areas such as wetlands and termite mounds. Wetlands are important edaphic contrasts in savannas and are paradoxically prevalent in the semi-arid to arid regions. In Southern Africa endorheic (inward draining) wetlands, known as pans, are particularly ubiquitous in arid regions but are not well studied compared to other wetland types. These wetlands were the focus of this study, which took place in the semi-arid savanna of the Limpopo plains, South Africa. The key research aims of this study were to determine how the pans differed from the surrounding terrestrial savanna landscape with respect to soil texture and chemistry, woody plant density and vegetation species composition. Top and sub soil samples were analysed to a depth of 30 and 60 cm and vegetation transects were carried out across three identified 'hydro-ecological' zones, i.e. the pan centre, the wooded wetland zone around the pan and representative terrestrial savanna habitat. In addition, drone aerial imagery was utilised to accurately determine woody species density and visually understand habitat changes. As hypothesised, the physiochemical properties of the soils differed along the study gradient from terrestrial to wetland, where in general the soil fertility, clay content and water holding capacity increased. The high clay content of the pans facilitates the surface pooling of rainwater and the possible maintenance of wetland conditions in these depressions which were found to be localised soil nutrient hotspots. The wooded wetland and terrestrial areas differed from each other in woody species composition where the terrestrial areas were largely dominated by broad leafed tree and shrub species and the wooded wetland areas had few to no broad-leafed species present but rather a dominance of fine-leafed Senegalia/Vachelia species. In addition, the Senegalia/Vachelia dominated habitat had a higher tree density than the surrounding bushveld, forming closed canopy patches in some areas. This change in vegetation and soil dynamics are important in savanna ecology as these habitats function quite differently from each other with respect to nutrient cycling, herbivore behaviour and biodiversity. It was concluded that these pans are nutrient-rich hotspots, likely playing an important ecological role in the savanna landscape. Furthermore, as they are likely to be key water sources and preferential forage sites, they could be the first to show signs of degradation and be useful indicators for land managers. These pans should be highlighted as sensitive habitats with regional conservation significance, which are deserving of adequate protection from surrounding threats such as mining. [ABSTRACT FROM AUTHOR]

Reconstructing the historical interplay of wildlife and pastoralists in the African savannas is clouded in contemporary studies by the transformation of subsistence societies and land use changes. We draw on five decades of monitoring by the Amboseli Conservation Program to illustrate the rainfall–plant–herbivore linkages in a free‐ranging wildlife–livestock system transitioning to contemporary savanna landscapes. In half a century, the coupled interactions of wildlife and livestock in the Amboseli ecosystem driven by rainfall and water sources have been severed and reshaped by farming, land subdivision, sedentism, poaching, and intensified herbivory. Livestock ranges have expanded, wildlife ranges have contracted, and overlapping spatial use has fluctuated with population sizes. In contrast, wildlife and livestock herds have been sustained where the rangelands remain open. A decrease in the mean body size reflecting a shift to small stock among pastoralists has increased species dominance, decreased diversity, and elevated biomass turnover and the probability of extreme shortfalls. In recent droughts, pastoralists have been importing food supplements to reduce drought risk and purchased livestock to restock herds, further uncoupling the rainfall‐herbivore link. Our study reinforces the view that biomes worldwide are shaped at an accelerating pace by human agencies rather than endogenous environmental factors. Disputes over models of rangeland systems echo the wider debate over using natural ecosystems as benchmarks for conservation verses "gardening" nature. We argue that models of natural ecosystems fail to account for the dominant role of humans in contemporary ecosystem yet that it is possible to monitor the complex interplay of human and natural systems and interpret the changes in terms of ecological function using macroecological analysis. The key finding for conservation is the importance of space, landscape heterogeneity, social networks, and mobility in sustaining the large herbivore populations. [ABSTRACT FROM AUTHOR]

Background: Studies of the African savannas have used national parks to test ecological theories of natural ecosystems, including equilibrium, non-equilibrium, complex adaptive systems, and the role of top-down and bottom-up physical and biotic forces. Most such studies have excluded the impact of pastoralists in shaping grassland ecosystems and, over the last half century, the growing human impact on the world's rangelands. The mounting human impact calls for selecting indicators and integrated monitoring methods able to track ecosystem changes and the role of natural and human agencies. Our study draws on five decades of monitoring the Amboseli landscape in southern Kenya to document the declining role of natural agencies in shaping plant ecology with rising human impact. Results: We show that plant diversity and productivity have declined, biomass turnover has increased in response to a downsizing of mean plant size, and that ecological resilience has declined with the rising probability of extreme shortfalls in pasture production. The signature of rainfall and physical agencies in driving ecosystem properties has decreased sharply with growing human impact. We compare the Amboseli findings to the long-term studies of Kruger and Serengeti national parks to show that the human influence, whether by design or default, is increasingly shaping the ecology of savanna ecosystems. We look at the findings in the larger perspective of human impact on African grasslands and the world rangelands, in general, and discuss the implications for ecosystem theory and conservation policy and management. Conclusions: The Amboseli study shows the value of using long-term integrated ecological monitoring to track the spatial and temporal changes in the species composition, structure, and function of rangeland ecosystems and the role of natural and human agencies in the process of change. The study echoes the widespread changes underway across African savannas and world's rangelands, concluding that some level of ecosystem management is needed to prevent land degradation and the erosion of ecological function, services, and resilience. Despite the weak application of ecological theory to conservation management, a plant trait-based approach is shown to be useful in explaining the macroecological changes underway. [ABSTRACT FROM AUTHOR]

Millions of hectares devoted to cereal production in Africa were affected by Striga infestation across locations and time. A study was conducted in 2012 and 2013 rainy seasons at the Teaching and Research Farms of Niger State College of Agriculture, Mokwa and the Teaching and Research Farms of Federal University of Technology, Minna, in the Southern Guinea Savanna ecology of Nigeria to determine cereal / legume intercropping and N fertilization effects on Striga infestation, Soil C and N and grain yield of maize. The treatments consisted of four inorganic N fertilizer levels (0, 60, 90, 120 kg ha-1), alternate hill and same hill intercropping of Aeschynomene histrix. Intercropping maize with A. histrix has the potential of reducing Striga parasitism with about 33-47% with respect to Striga shoots per m-2 and Striga shoots per plot thus, enhancing maize grain yield. The use of herbaceous legumes in intercropping contributed about 58% SOC and 52-57% reduction in number of S. hermonthica due to application of N using urea, thereby helping to control Striga infestation. Intercropping maize with A. histrix improved the soil organic matter and hence, the physical, chemical and biological properties of the soil for good crop growth. Incorporation of the A. histrix residues substantially increased the soil N content. There was response to inorganic N fertilizer application, suggesting the need for N application to maize for optimum grain yield. Nitrogen rate of 60 kg ha-1 was optimum for maize yield in the study area. [ABSTRACT FROM AUTHOR]

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Plinthite occurs in most parts of savannah soil at varying depths, thus limiting the productivity of the soil for crop production. However, plinthic soils are not well defined in the USDA classification. Therefore, we surveyed nine plinthites bearing pedons, to characterize their suitability, quality and sustainability over the basement complex formation in southwestern Nigeria; and to suggest new classification based on USDA and FAO classification systems. In the entire land area, two types of hardened plinthites were identified: 41% with petroferric contact and 59% with petroplinthite. The percentage of aggregate soil quality indices of both petroferric contact and petroplinthite was low to moderate, ranging from 32% to 56%. Sustainability indices of the soils ranged from 20 to 37 with petroferric contact have the lowest index while soils with petroplinthite have the moderate index. Setting up an integrated conservation structure with soil amendments is essential for the sustainability of petroplinthite soils but petroferric contact, even with high inputs, cannot sustain intensive cropping, and therefore, recommended for pasture and forestry. The inclusion of hyperplinthic and orthoplinthic in USDA and FAO-WRSB classification systems as classes of petroplinthite is hereby suggested. [ABSTRACT FROM AUTHOR]

The article discusses the "mismatch" between evolved human physiology and Western lifestyles has thought to explain the epidemic of cardiovascular disease in industrialized societies. Topics include attempts to test the evolutionary mismatch hypothesis have focused on comparing cardiometabolic health outcomes between industrialized nations and small-scale; and the "mismatch" between human physiology evolved to cope with a mixed plant- and meat-based diet.

The article offers information on Seasonal dietary changes which increase the abundances of savanna herbivore species. It mentions clear mixed-feeder dominance may reflect a historical pattern or may instead mirror a general global decline in specialists; and mixed feeders dominate the savannas of the present and future.

Summary: Dimensions of tree root systems in savannas are poorly understood, despite being essential in resource acquisition and post‐disturbance recovery. We studied tree rooting patterns in Southern African savannas to ask: how tree rooting strategies affected species responses to severe drought; and how potential rooting depths varied across gradients in soil texture and rainfall.First, detailed excavations of eight species in Kruger National Park suggest that the ratio of deep to shallow taproot diameters provides a reasonable proxy for potential rooting depth, facilitating extensive interspecific comparison. Detailed excavations also suggest that allocation to deep roots traded off with shallow lateral root investment, and that drought‐sensitive species rooted more shallowly than drought‐resistant ones.More broadly across 57 species in Southern Africa, potential rooting depths were phylogenetically constrained, with investment to deep roots evident among miombo Detarioids, consistent with results suggesting they green up before onset of seasonal rains. Soil substrate explained variation, with deeper roots on sandy, nutrient‐poor soils relative to clayey, nutrient‐rich ones. Although potential rooting depth decreased with increasing wet season length, mean annual rainfall had no systematic effect on rooting depth.Overall, our results suggest that rooting depth systematically structures the ecology of savanna trees. Further work examining other anatomical and physiological root traits should be a priority for understanding savanna responses to changing climate and disturbances. [ABSTRACT FROM AUTHOR]

African termites are classified into five distinct families, Termitidae, Rhinotermitidae, Hodotermitidae, Termopsidae and Kalotermitidae. Termites are undoubtedly one of the key ecosystem engineers. Because they harbour more nutritive plants, herbivory by large herbivores is biased towards mounds. Their engineering role is visible through construction of conspicuous termite mounds, which often harbour some unique species compared with the expansive ecosystem in which they occur. To understand the cascading effects of termite mounds on ecosystem functioning, we present a review on how termites create ecosystem heterogeneity, and how this heterogeneity in terms of soil physical and chemical characteristics, particularly nutrients, further influences vegetation production, diversity and palatability to large herbivores. Here we review literature mainly focusing on: (i) Phylogeny (evolutionary history) of African termites, (ii) mound construction, (iii) mound spatial distribution, (iv) termite foraging (v) termite nutrient cycling, (vi) termite influence on hydrology, (vii) termite mound influence on plant species diversity and (viii) termite mound influence on large herbivores. Our review showed that African termites are diverse, with the potential to influence ecosystems heterogeneity through soil nutrients enrichment, which in turn influences forage abundance (thicket clumps), diversity and quality. High forage quality occurring on termite mounds influences herbivory patterns in the savanna ecosystem. Herbivory is reported to be higher on termite mounds compared to the expansive savanna landscape. The most common plant family occurring on termite mounds is Capparaceae. We suggest that future studies focus more on: (1) the influence of termite mounds on plant functional traits, (2) the importance of termite mounds in dryland savanna cropping/rangeland systems, and (3) on ways to support establishment of mound building termite species. [ABSTRACT FROM AUTHOR]

Managing fire, water, biodiversity and carbon stocks can greatly benefit from early warning of changes in the state of vegetation. While near-real time tools to detect forest change based on satellite remote sensing exist, these ecosystems have relatively stable natural vegetation dynamics. Open (i.e. non-forest) ecosystems like grasslands, savannas and shrublands are more challenging as they show complex natural dynamics due to factors such as fire, postfire recovery, greater contribution of bare soil to observed vegetation indices, as well as high sensitivity to rainfall and strong seasonality. Tools to aid the management of open ecosystems are desperately required as they dominate much of the globe and harbour substantial biodiversity and carbon. We present an innovative approach that overcomes the difficulties posed by open ecosystems by using a spatio-temporal hierarchical Bayesian model that uses data on climate, topography, soils and fire history to generate ecological forecasts of the expected land surface signal under natural conditions. This allows us to monitor and detect abrupt or gradual changes in the state of an ecosystem in near-real time by identifying areas where the observed vegetation signal has deviated from the expected natural variation. We apply our approach to a case study from the hyperdiverse fire-dependent African shrubland, the fynbos of the Cape Floristic Region, a Global Biodiversity Hotspot and UNESCO World Heritage Site that faces a number of threats to vegetation health and ecosystem function. The case study demonstrates that our approach is useful for identifying a range of change agents such as fire, alien plant species invasions, drought, pathogen outbreaks and clearing of vegetation. We describe and provide our full workflow, including an interactive web application. Our approach is highly versatile, allowing us to collect data on the impacts of change agents for research in ecology and earth system science, and to predict aspects of ecosystem structure and function such as biomass, fire return interval and the influence of vegetation on hydrology. [ABSTRACT FROM AUTHOR]

In livestock-based livelihoods of the developing world, determination of the nutritive value of browse species is mainly associated with farmer perceptions. Additionally, little is known on seasonal variation in nutritive value of these species in some areas. Therefore, chemical analysis is necessary to validate farmer nutritive value ranking, because this has implications on rangeland management. We compared farmer perceptions with chemically quantified crude protein, dry matter, acid detergent fibre (ADF), and dry organic matter digestibility (DOMD) of seven browse species. Crude protein and DOMD were higher in the wet season compared to the dry season. However, ADF was higher in the dry season. There was a strong negative correlation between acid detergent fibre and DOMD during the wet season (r = −0.631, p < 0.05). Positive, though non-significant correlations were observed between farmer perceptions of 'most nutritious according to herder' and CP (r = 0.29, p = 0.54), farmer perception of 'most abundant species' and DM (r = 0.13, p = 0.78), and between farmer perception of 'highly preferred species by livestock' and DOMD (r = 0.32, p = 0.48). Therefore, although farmer perceptions of nutritive value of browse species are important in strategic utilisation of rangelands, they should not replace chemical analysis, but should complement each other. [ABSTRACT FROM AUTHOR]

A study on the effect of bush control methods on encroaching woody species, namely Acacia drepanolobium, Acacia mellifera and Acacia reficiens was conducted for a 2 years' time. A 3 ha of land was divided into two plots. Each replication with an area of 300 m × 50 m was again sub-divided into six plots (each 50 m × 50 m) to accommodate six treatments. Bush control treatments were assigned randomly to the plots and replicated two times across sites of similar topography. During the post-treatment period, responses of woody species to different treatments in terms of mortality and coppicing were monitored. Data was analysed using R software and Tukey's studentized range tests for comparisons of means. The applied treatments significantly influenced (P < 0.05) encroaching woody species. The finding showed that five out of the six bush control treatments greatly promoted woody mortality, however with species-specific differences. The stem-burning, tree cutting with fire–browse combination, cutting and fire, cutting and browsing, and cutting treatments greatly increased species mortality compared to the control treatment. Responses due to treatment effect also varied significantly (P < 0.05) among encroaching woody species. Accordingly, mortality was higher in A. reficiens than in the other two species, indicating that A. reficiens is greatly susceptible to the applied treatments. The significant finding was that woody species exhibited greater mortality in response to selective cutting/thinning and post-management techniques. Post-thinning management measures would sustain savanna ecology, if implemented at certain intervals. [ABSTRACT FROM AUTHOR]