Sustainable Grassland Management Research Articles

Environmental and management controls of soil carbon storage in grasslands of southwestern China

In order to predict the effects of climate change on the global carbon cycle, it is crucial to understand the environmental factors that affect soil carbon storage in grasslands. In the present study, we attempted to explain the relationships between the distribution of soil carbon storage with climate, soil types, soil properties and topographical factors across different types of grasslands with different grazing regimes. We measured soil organic carbon in 92 locations at different soil depth increments, from 0 to 100 cm in southwestern China. Among soil types, brown earth soils (Luvisols) had the highest carbon storage with 19.5 ± 2.5 kg m−2, while chernozem soils had the lowest with 6.8 ± 1.2 kg m−2. Mean annual temperature and precipitation, exerted a significant, but, contrasting effects on soil carbon storage. Soil carbon storage increased as mean annual temperature decreased and as mean annual precipitation increased. Across different grassland types, the mean carbon storage for the top 100 cm varied from 7.6 ± 1.3 kg m−2 for temperate desert to 17.3 ± 2.9 kg m−2 for alpine meadow. Grazing/cutting regimes significantly affected soil carbon storage with lowest value (7.9 ± 1.5 kg m−2) recorded for cutting grass, while seasonal (11.4 ± 1.3 kg m−2) and year-long (12.2 ± 1.9 kg m−2) grazing increased carbon storage. The highest carbon storage was found in the completely ungrazed areas (16.7 ± 2.9 kg m−2). Climatic factors, along with soil types and topographical factors, controlled soil carbon density along a soil depth in grasslands. Environmental factors alone explained about 60% of the total variation in soil carbon storage. The actual depth-wise distribution of soil carbon contents was significantly influenced by the grazing intensity and topographical factors. Overall, policy-makers should focus on reducing the grazing intensity and land conversion for the sustainable management of grasslands and C sequestration.

Looking to the future: key points for sustainable management of northern Great Plains grasslands

The grasslands of the northern Great Plains (NGP) region of North America are considered endangered ecosystems and priority conservation areas yet have great ecological and economic importance. Grasslands in the NGP are no longer self‐regulating adaptive systems. The challenges to these grasslands are widespread and serious (e.g. climate change, invasive species, fragmentation, altered disturbance regimes, and anthropogenic chemical loads). Because the challenges facing the region are dynamic, complex, and persistent, a paradigm shift in how we approach restoration and management of the grasslands in the NGP is imperative. The goal of this article is to highlight four key points for land managers and restoration practitioners to consider when planning management or restoration actions. First, we discuss the appropriateness of using historical fidelity as a restoration or management target because of changing climate, widespread pervasiveness of invasive species, the high level of fragmentation, and altered disturbance regimes. Second, we highlight ecosystem resilience and long‐term population persistence as alternative targets. Third, because the NGP is so heavily impacted with anthropogenic chemical loading, we discuss the risks of ecological traps and extinction debt. Finally, we highlight the importance of using adaptive management and having patience during restoration and management. Consideration of these four points will help management and restoration of grasslands move toward a more successful and sustainable future. Although we specifically focus on the NGP of North America, these same issues and considerations apply to grasslands and many other ecosystems globally.

Potential for organic conversion and energy efficiency of conventional livestock production in a humid tropical region of Mexico

Abstract Organic livestock production uses low levels of external inputs and less fossil fuel than does conventional livestock production, and therefore it is more energy efficient, reduces contamination, provides healthy food and ecosystem services, and contributes to reducing and adapting to climate change. This article characterizes livestock production and evaluates the potential and limitations of organic conversion and the energy efficiency of conventional dual purpose (milk and meat) cattle production in a humid tropical region of Chiapas, Mexico. Our analysis indicates that for the Livestock Production Units (LPU) of the study region, the greater the organic livestock conversion index (OLCI, 0–100%), the lower the values for herd size, stocking rate, total feed supplement, annual cost of feed purchased for cattle, and production cost per cow; by contrast, those LPU with greater OLCI have greater economic efficiency. Furthermore, the greater the OLCI, the greater the values of the following indicators: Feeding management, Sustainable grassland management, Ecological weed control in grasses and crops, Veterinary prevention and care, Food safety, and Ecological farm management. A direct relationship exists between the potential for organic conversion (>OLCI) and energy and economic efficiency. Meanwhile, an inverse relationship was found between OLCI and energy efficiency on the one hand, and - on the other - use of direct and indirect energy, total energy input, energy output, and number of people that could be fed with the energy from milk and meat produced. Converting LPU to organic production and increasing their energy efficiency depends on farmers further developing their abilities to manage sustainable agricultural systems through advisory, technical assistance, and permanent financial support.

Responses of soil organic carbon and nitrogen to land-use changes in a semiarid region of northwest China

Currently, we lack a clear understanding of how climate influences the responses of soil organic carbon (OC) and nitrogen (N) to land-use changes in semiarid regions. Thus, to clarify the mechanisms involved, we measured the soil OC and total N (TN) concentrations and stocks in the 0–100 cm soil layer in adjacent grassland, farmland, and woodland at five sites on the Loess Plateau in China, which varied in terms of the mean annual precipitation (MAP) and mean annual temperature (MAT). The farmland or woodland was converted from grassland at each site. Conversion of grassland to farmland significantly reduced the soil OC and TN, with greater decreases in sites with relatively lower MAP and MAT (–0.60 Mg OC ha−1 yr−1 and –0.22 Mg TN ha−1 yr−1, respectively) than sites with relatively higher MAP and MAT (–0.35 Mg OC ha−1 yr−1 and –0.04 Mg TN ha−1 yr−1). Conversion of grassland to woodland increased OC and TN at sites with higher MAP and MAT, but decreased them at sites with lower MAP and MAT. OC and TN increased to a depth of 100 cm with MAP and MAT after this land-use change. OC and TN decreased at relatively drier and colder sites, but increased at relatively wetter and warmer sites. These findings provide insights into the effects of land-use changes on the soil OC and TN under different climate conditions, thereby facilitating the sustainable management of grasslands in semiarid regions.

Dynamic forage-livestock balance analysis in alpine grasslands on the Northern Tibetan Plateau

Forage-livestock balance is important for sustainable management of alpine grasslands under global change, but the robustness of diverse algorithms for assessing forage-livestock balance is still unclear. This study compiled long-term (2009–2014) field observations of aboveground biomass (AGB). Using climate and remote sensing data, we evaluated the inter-annual dynamics of the forage-livestock balance on the Northern Tibetan Plateau (NTP). Here, we assumed that AGB dynamics in fenced grasslands (AGBF) is only driven by climate change; whereas AGB dynamics in open grasslands grazed by livestock (AGBG) is driven by a combination of climate change and human activities. Thus, human-induced change in AGB (AGBH) could be estimated via the difference between AGBF and AGBG. Furthermore, differences in the temporal trends between AGBF and AGBH could indicate the state of forage-livestock balance, overgrazed or not, in alpine grasslands. Our results showed that the overall status of the forage-livestock balance from 2000 to 2006 was overgrazed owing to poor climatic conditions. Ecological projects and economic policies for alpine grassland conservation had not been implemented at that time, which also resulted in local overgrazing. From 2006 to 2014, the alpine grasslands in some areas were in a less-grazed state. We suggest that the livestock number could potentially increase in northern NTP and should be reduced or strictly controlled to maintain the balance between livestock and forage in the southern and southeast areas. In conclusion, the results of this study suggest that the evaluation of the forage-livestock balance in the NTP should include the local climatic conditions and make better use of grassland resources while ensuring ecological security.

Distribution of soil organic carbon and potential carbon sequestration in an alpine meadow grazed by domesticated yak in Zeku, Qinghai-Tibetan Plateau, China

The effects of grazing on the soil carbon of an alpine meadow on the Qinghai-Tibetan Plateau were studied. The aims were to estimate the effects of grazing on the spatial and vertical distribution of soil organic carbon, estimate the potential carbon sink and provide suggestions for sustainable grassland management. Biomass and soil characteristics of the topmost 1 m soil layer in plots under three different grazing intensities were investigated. Soil organic carbon density (SOCD) and stocks (SOCS) were calculated as weighted averages. Soil organic carbon content (SOCC) decreased with increasing grazing intensity and soil depth, with the highest values observed in the top 30 cm of the soil layer at light grazing (LG) sites. Soil water content, total carbon, and biomass had a positive relationship with SOCC. However, bulk density was negatively correlated with SOCC. The lowest SOCD and SOCS were in the 30–100 cm soil layer at heavy grazing (HG) sites, indicating that HG could have significant negative effects on SOC. It could take at least ∼60 years for C stocks at HG sites to reach a steady state. A regime of low grazing is recommended for combining C sequestration with sustainable development.

A multitiered approach for grassland ecosystem services mapping and assessment: The Viva Grass tool

Throughout the second half of the 20th Century, the area of semi-natural grasslands in the Baltic States decreased substantially, due to agricultural abandonment in some areas and intensification in more productive soil types. In order to halt the loss of biodiversity and ecosystem services provided by grasslands, the LIFE+ programme funded project, LIFE Viva Grass, aims at developing an integrated planning tool that will support ecosystem-based planning and sustainable grassland management. LIFE Viva Grass integrated planning tool is spatially explicit and allows the user to assess the provision and trade-offs of grassland ecosystem services within eight project case study areas in Estonia, Latvia and Lithuania. In order to ensure methodological adaptability, the structure of the LIFE Viva Grass integrated planning tool follows the framework of the tiered approach. In a multi-tier system, each consecutive tier entails an increase in data requirements, methodological complexity or both. The present paper outlines the adaptation of the tiered approach for mapping and assessing ecosystem services provided by grasslands in the Baltic States. The first tier corresponds to a deliberative decision process: The matrix approach is used to assess the potential supply of grassland ecosystem services based on expert estimations. Expert values are subsequently transferred to grassland units and therefore made spatially explicit. The data collected in the first tier was further enhanced through a Principal Components Analysis (PCA) in order to explore ES bundles in tier 2. In the third tier, Multi-Criteria Decision Analysis is used to target specific policy questions.

Divergrass – a cross border project to promote sustainable management of grasslands

Divergrass – a cross border project to promote sustainable management of grasslands

Interactive effects of wind speed, vegetation coverage and soil moisture in controlling wind erosion in a temperate desert steppe, Inner Mongolia of China

The rapid desertification of grasslands in Inner Mongolia of China poses a significant ecological threaten to northern China. The combined effects of anthropogenic disturbances (e.g., overgrazing) and biophysical processes (e.g., soil erosion) have led to vegetation degradation and the consequent acceleration of regional desertification. Thus, mitigating the accelerated wind erosion, a cause and effect of grassland desertification, is critical for the sustainable management of grasslands. Here, a combination of mobile wind tunnel experiments and wind erosion model was used to explore the effects of different levels of vegetation coverage, soil moisture and wind speed on wind erosion at different positions of a slope inside an enclosed desert steppe in the Xilamuren grassland of Inner Mongolia. The results indicated a significant spatial difference in wind erosion intensities depending on the vegetation coverage, with a strong decreasing trend from the top to the base of the slope. Increasing vegetation coverage resulted in a rapid decrease in wind erosion as explained by a power function correlation. Vegetation coverage was found to be a dominant control on wind erosion by increasing the surface roughness and by lowering the threshold wind velocity for erosion. The critical vegetation coverage required for effectively controlling wind erosion was found to be higher than 60%. Further, the wind erosion rates were negatively correlated with surface soil moisture and the mass flux in aeolian sand transport increased with increasing wind speed. We developed a mathematical model of wind erosion based on the results of an orthogonal array design. The results from the model simulation indicated that the standardized regression coefficients of the main effects of the three factors (vegetation coverage, soil moisture and wind speed) on the mass flux in aeolian sand transport were in the following order: wind speed>vegetation coverage>soil moisture. These three factors had different levels of interactive effects on the mass flux in aeolian sand transport. Our results will improve the understanding of the interactive effects of wind speed, vegetation coverage and soil moisture in controlling wind erosion in desert steppes, and will be helpful for the design of desertification control programs in future.

The challenge of abandonment for the sustainable management of Palaearctic natural and semi-natural grasslands

AbstractDisturbance by biomass removal is a crucial mechanism maintaining the diversity of Palaearctic grasslands, which are unique biodiversity hotspots. The century-long traditional land use of mowing, grazing and burning, has been fundamentally changed in many parts of the Palaearctic. Due to socio-economic changes, large areas of former pastures and meadows have been abandoned, leading to a succession towards secondary scrublands or forest and the encroachment of competitor grass species, all leading to a decrease in biodiversity. Here we report the causes and consequences of the cessation of traditional grassland management regimes, provide strategies for reducing the impact of abandonment and consider these from the perspective of sustainability. We consider the possibilities for initiating sustainable management regimes in the contemporary socio-economic environment, and discuss the prospects and limitation of alternative management regimes in the conservation of grassland biodiversity. These themes are also the core topics of this Special Feature, edited by the EDGG. We hope that this Special Feature will encourage steps towards more sustainable strategies for the conservation of Palaearctic grasslands and the integration of the sustainability perspective into their conservation.

Sustainable management of Chinese grasslands—issues and knowledge

Sustainable management of Chinese grasslands—issues and knowledge

Using balance of seasonal herbage supply and demand to inform sustainable grassland management on the Qinghai–Tibetan Plateau

To mitigate the impacts of grassland degradation on the Qinghai–Tibetan Plateau (QTP), in recent decades China has been implementing large-scale conservation programs and has invested about 42 billion CNY (7 billion USD). However, these programs are faced with major challenges involving trade-offs between ecological function, livestock production and income of pastoralists. Scientific assessments, as well as technical and policy issues, have not fully captured the complex ecological, social and economic dynamics of the challenges facing grassland management on the QTP. Pastoral livestock production on the QTP is characterized by imbalance in both quality and quantity between livestock seasonal nutrient requirements and herbage production, which forces pastoralists to keep larger numbers of livestock for longer periods, leading to overgrazing. To solve these problems, an integrated crop-livestock system is promoted to improve the efficiency of livestock production and conserve natural grassland as well for a sustainable system for the QTP.

Carbon storage potential increases with increasing ratio of C4 to C3 grass cover and soil productivity in restored tallgrass prairies.

Long-term soil carbon (C) storage is essential for reducing CO2 in the atmosphere. Converting unproductive and environmentally sensitive agricultural lands to grasslands for bioenergy production may enhance C storage. However, a better understanding of the interacting effects of grass functional composition (i.e., relative abundance of C4 and C3 grass cover) and soil productivity on C storage will help guide sustainable grassland management. Our objective was to examine the relationship between grass functional composition and potential C storage and how it varies with potential soil productivity. We estimated C inputs from above- and belowground net primary productivity (ANPP and BNPP), and heterotrophic respiration (R H) to calculate net ecosystem production (NEP), a measure of potential soil C storage, in grassland plots of relatively high- and low-productivity soils spanning a gradient in the ratio of C4 to C3 grass cover (C4:C3). NEP increased with increasing C4:C3, but only in potentially productive soils. The positive relationship likely stemmed from increased ANPP, rather than BNPP, which was possibly related to efficient resource-use and physiological/anatomical advantages of C4 plants. R H was negatively correlated with C4:C3, possibly because of changes in microclimate or plant-microbe interactions. It is possible that in potentially productive soils, C storage can be enhanced by favoring C4 over C3 grasses through increased ANPP and BNPP and reduced R H. Results also suggest that potential C storage gains from C4 productivity would not be undermined by a corresponding increase in R H.

Plant diversity in a water-meadow landscape: the role of irrigation ditches

Species-rich, extensively managed grasslands are among the most threatened ecosystems in Europe. The traditional technique of meadow irrigation, formerly practised in large parts of Europe, may be a viable management option that meets both ecological and economical objectives. While studies on plant diversity of the meadow matrix exist, the role of other landscape components for biodiversity conservation is unknown. We quantify the role of irrigation and drainage ditches compared with field paths, and analysed the local and landscape plant species composition and diversity in a water-meadow landscape. The meadows are located in the river Queich catchment (Upper Rhine valley, Germany). We recorded plant species cover on 18 meadows, adjacent ditches and field paths and analysed alpha, beta and gamma diversity within and among these landscape components. Irrigation and drainage ditches were more species rich than meadows and more heterogeneous in their species composition compared with meadows and paths. Ditches contributed one-third of the landscape’s plant species numbers, habitat for wetland species and refuges for high nature value grassland species. Fertilization of the adjacent meadow had no negative impact on the ditch diversity, while well-maintained ditches were more plant species rich than ditches filled with sediments. Traditional flood meadow irrigation should be taken into account when sustainable grassland management techniques are discussed that meet economical and ecological needs. A major contribution to landscape richness arises from the ditch structures as crucial part of the traditional irrigation technique.

Contrasting processes drive alpha and beta taxonomic, functional and phylogenetic diversity of orthopteran communities in grasslands

Taxonomic, functional and phylogenetic diversities can respond differently to biotic and abiotic filters. However, biodiversity management tends to focus on a single index, generally taxonomic diversity, assuming a strong positive correlation among biodiversity components across scales. This can result in a mismanagement of functional and phylogenetic diversities with negative consequences for ecosystem functioning and long-term maintenance of services. Understanding the relationships among biodiversity components, how they change across scales and which their main drivers are can lead to more sustainable management of biodiversity and its associated ecosystem services and functions.We used an integrative approach of biodiversity where we investigated alpha and beta taxonomic (TD), functional (FD) and phylogenetic (PD) diversity of orthopteran communities as well as species and functional traits composition and their associated drivers at the local and landscape scales in permanent mesic grasslands of the French Jura Mountains. We assessed whether orthopteran TD, FD and PD were positively correlated. We also determined the drivers of TD, FD and PD and their changes across scales and among indices using data related to soil, agricultural practices, elevation, and biotic interactions with plants.Our results showed that (i) elevation was a strong driver of orthopteran community trait composition, (ii) orthopteran alpha TD, FD and PD were correlated among themselves and increased with plant species richness, and (iii) local beta diversity was not correlated with alpha diversity. Beta diversity had different drivers at local and landscape scale: it was influenced by soil chemistry and texture at the local scale and increased with the difference in elevation among plots at the landscape scale.This study evidences distinct processes driving alpha and beta diversity of orthopteran communities at both the local and landscape scales. It supports the hypothesis that less intensive agricultural practices enhance orthopteran diversity and highlights the importance to consider beta diversity at both local and landscape scale when designing and assessing the management regimes of grassland ecosystems. Prioritizing the importance of the different biodiversity components and spatial scales constitutes an important challenge for sustainable grassland management.

Modelling biomass of mountainous grasslands by including a species composition map

High mountain grasslands offer multiple goods and services to society but are severely threatened by improper land use practices such as abandonment or rapid intensification. In order to reduce abandonment and strengthen the common extensive agricultural practice a sustainable land use management of high mountain grasslands is needed. A spatially detailed yield assessment helps to identify possible meadows or, on the contrary, areas with a low carrying capacity in a region, making it easier to manage these sites. Such assessments are rarely available for remote and inaccessible areas. Remotely sensed vegetation indices are able to provide valuable information on grassland properties. These indices tend, however, to saturate for high biomass. This affects their applicability to assessments of high-yield grasslands.The main aim of this study was to model a spatially explicit grassland yield map and to test whether saturation issues can be tackled by consideration of plant species composition in the modelling process. The high mountain grassland of the subalpine belt (1800 – 2500m a.s.l.) in the Kazbegi region, Greater Caucasus, Georgia, was chosen as test site for its strong species composition and yield gradients.We first modelled the species composition of the grassland described as metrically scaled gradients in the form of ordination axes by random forest regression. We then derived vegetation indices from Rapid Eye imagery, and topographic variables from a digital elevation model, which we used together with the multispectral bands as predictive variables. For comparison, we performed two yield models, one excluding the species composition maps and one including the species composition map as predictors. Moreover, we performed a third individual model, with species composition as predictors and a split dataset, to produce the final yield map.Three main grassland types were found in the vegetation analysis: Hordeum violaceum-meadows, Gentianella caucasea-grassland and Astragalus captiosus-grassland. The three random forest regression models for the ordination axes explained 64%, 33% and 46% of the variance in species composition. Independent validation of modelled ordination scores against a validation data set resulted in an R2 of 0.64, 0.32 and 0.46 for the first, second and third axes, respectively. The model based on species composition resulted in a R2=0.55, whereas the benchmark model showed weaker relationships between yield and the multispectral reflectance, vegetation indices, and topographical parameters (R2=0.42). The final random forest yield model used to derive the yield map resulted in 62% variance explained and an R2=0.64 between predicted and observed biomass. The results further indicate that high yields are generally difficult to predict with both models.The benefit of including a species composition map as a predictor variable for grassland yield lies in the preservation of ecologically meaningful features, especially the occurrence of high yielding vegetation type of Hordeum violaceum meadows is depicted accurately in the map. Even though we used a gradient based design, sharp boundaries or immediate changes in productivity were visible, especially in small structures such as arable fields or roads (Fig. 6b), making it a valuable tool for sustainable land use management. The saturation effect however, was mitigated by using species composition as predictor variables but is still present at high yields.

Interactions between ecosystem properties and land use clarify spatial strategies to optimize trade-offs between agriculture and species conservation

ABSTRACTSpecies conservation and forage production are both important, yet conflicting components of sustainable grassland management. We modeled forage production and conservation value as dependents in a chain of responses and effects, starting with abiotic environmental conditions that affect the spatial distribution of land uses and biotic ecosystem properties. We asked which relationships in this causal chain determine trade-offs between forage production and conservation value. Abiotic and biotic ecosystem properties were recorded on 46 plots in the coastal marshes of Northwest Germany. Plant and bird conservation values were calculated using Red Lists, and sales of forage-based agricultural products were assessed by interviewing farmers. We used a structural equation model to determine responses and effects. Groundwater depth and salinity represent the ultimate causes for the spatial variation in sales and conservation value. The water gradient translated into more proximate causes, such as land-use intensity affecting aboveground net primary productivity, forage quality, and species richness. Plant species conservation and forage production were segregated along the water gradient, and both bird conservation and forage production depended on grassland management, albeit at different fertilization levels. Our study points to segregation and integration as two spatial strategies to react to trade-offs between services.EDITED BY Christine Fürst

Quantification of dead vegetation fraction in mixed pastures using AisaFENIX imaging spectroscopy data

New Zealand farming relies heavily on grazed pasture for feeding livestock; therefore it is important to provide high quality palatable grass in order to maintain profitable and sustainable grassland management. The presence of non-photosynthetic vegetation (NPV) such as dead vegetation in pastures severely limits the quality and productivity of pastures. Quantifying the fraction of dead vegetation in mixed pastures is a great challenge even with remote sensing approaches. In this study, a high spatial resolution with pixel resolution of 1m and spectral resolution of 3.5–5.6nm imaging spectroscopy data from AisaFENIX (380–2500nm) was used to assess the fraction of dead vegetation component in mixed pastures on a hill country farm in New Zealand. We used different methods to retrieve dead vegetation fraction from the spectra; narrow band vegetation indices, full spectrum based partial least squares (PLS) regression and feature selection based PLS regression. Among all approaches, feature selection based PLS model exhibited better performance in terms of prediction accuracy (R2CV=0.73, RMSECV=6.05, RPDCV=2.25). The results were consistent with validation data, and also performed well on the external test data (R2=0.62, RMSE=8.06, RPD=2.06). In addition, statistical tests were conducted to ascertain the effect of topographical variables such as slope and aspect on the accumulation of the dead vegetation fraction. Steep slopes (>25°) had a significantly (p<0.05) higher amount of dead vegetation. In contrast, aspect showed non-significant impact on dead vegetation accumulation. The results from the study indicate that AisaFENIX imaging spectroscopy data could be a useful tool for mapping the dead vegetation fraction accurately.

Estimating Biomass of Native Grass Grown under Complex Management Treatments Using WorldView-3 Spectral Derivatives

The ability of texture models and red-edge to facilitate the detection of subtle structural vegetation traits could aid in discriminating and mapping grass quantity, a challenge that has been longstanding in the management of grasslands in southern Africa. Subsequently, this work sought to explore the robustness of integrating texture metrics and red-edge in predicting the above-ground biomass of grass growing under different levels of mowing and burning in grassland management treatments. Based on the sparse partial least squares regression algorithm, the results of this study showed that red-edge vegetation indices improved above-ground grass biomass from a root mean square error of perdition (RMSEP) of 0.83 kg/m2 to an RMSEP of 0.55 kg/m2. Texture models further improved the accuracy of grass biomass estimation to an RMSEP of 0.35 kg/m2. The combination of texture models and red-edge derivatives (red-edge-derived vegetation indices) resulted in an optimal prediction accuracy of RMSEP 0.2 kg/m2 across all grassland management treatments. These results illustrate the prospect of combining texture metrics with the red-edge in predicting grass biomass across complex grassland management treatments. This offers the detailed spatial information required for grassland policy-making and sustainable grassland management in data-scarce regions such as southern Africa.

Testing the capabilities of the new WorldView-3 space-borne sensor’s red-edge spectral band in discriminating and mapping complex grassland management treatments

ABSTRACTThe majority of grasslands are overused and poorly managed, globally. The overuse of these grasslands has resulted in the adoption of numerous management treatments as interventions for optimizing their productivity. However, there are limited comprehensive frameworks and objective precedents for monitoring these grasslands and rangelands. In that regard, understanding the effect of such rangeland management treatments on grassland productivity is, therefore, a critical step towards their effective conservation and sustainable management. This study sought to test the capabilities of the WorldView-3 (WV-3) satellite data derivatives in characterizing grasslands administered with different rangeland management treatments (i.e. mowing, grazing, burning, fertilizer application, and control: no-treatment), using discriminant analysis. We compared the accuracies obtained based on WV-3 standard visible and near-infrared bands and vegetation indices (VIs), excluding and including the red-edge. Results illustrate that incorporating the strategically positioned red-edge band improves the classification accuracy of the four different rangeland management treatments from 65% to 70%. Furthermore, the overall accuracy was 73% when standard VIs were used and it increased to 78% when the red-edge VIs were added to standard VIs. Other than the red-edge derivatives, the results of this study showed that the yellow, red, NIR-1, and NIR-2 bands were the most influential. The utility of fine spatial resolution sensors such as the newly launched WV-3, with strategically positioned bands (red-edge), could offer detailed information essential for the sustainable management of grasslands.