International audience | Land-use change is a major driver of biodiversity loss worldwide. Although biodiversity often shows a delayed response to land-use change, previous studies have typically focused on a narrow range of current landscape factors and have largely ignored the role of land-use history in shaping plant and animal communities and their functional characteristics. Here, we used a unique database of 220,000 land-use records to investigate how 20-y of land-use changes have affected functional diversity across multiple trophic groups (primary producers, mutualists, herbivores, invertebrate predators, and vertebrate predators) in 75 grassland fields with a broad range of land-use histories. The effects of land-use history on multitrophic trait diversity were as strong as other drivers known to impact biodiversity, e.g., grassland management and current landscape composition. The diversity of animal mobility and resource-acquisition traits was lower in landscapes where much of the land had been historically converted from grassland to crop. In contrast, functional biodiversity was higher in landscapes containing old permanent grasslands, most likely because they offer a stable and high-quality habitat refuge for species with low mobility and specialized feeding niches. Our study shows that grassland-to-crop conversion has long-lasting impacts on the functional biodiversity of agricultural ecosystems. Accordingly, land-use legacy effects must be considered in conservation programs aiming to protect agricultural biodiversity. In particular, the retention of permanent grassland sanctuaries within intensive landscapes may offset ecological debts.

Masters Degree. University of KwaZulu-Natal, Pietermaritzburg. | Twenty-five years after the Convention on Biological Diversity (CBD), much emphasis has been placed on the integration of biodiversity priorities and concerns into the development sectors. South Africa has made substantial progress in this regard. The understanding of threats to biodiversity, ecosystem services, sustainable development, and the link between ecosystem services and human well-being, in high levels of government, were fundamental factors in mainstreaming biodiversity in South Africa. The change in government and democratisation in 1994 has also facilitated the positive outcomes for integrating biodiversity into development. It has become a mandate for local government to address the socio-economic development needs of communities. Within the local land-use planning arena, the Integrated Development Plan (IDP) has been used as a comprehensive tool for guiding local development objectives. However, the promulgation of the Spatial Planning and Land Use Management Act (Act 16 of 2013) has elevated the status of the Spatial Development Framework (SDF) to guide other municipal plans. It has been suggested that integrating biodiversity priorities and conservation plans into comprehensive planning tools, such as the SDF, yields greater opportunity for biodiversity conservation to be prioritised in development planning and implementation. In contrast, the consideration of biodiversity priorities and conservation plans by local land-use planners during reactive post-hoc decision-making processes yields the least potential for biodiversity conservation. The main objective of this study was to assess the ability of local government to incorporate the principles of biodiversity conservation plans into their SDFs, and the implementation of these plans during their daily land use planning processes. I assess both suggestions in chapter 2 and chapter 3 of this thesis respectively. In chapter 2, I assess the review schedules, and the text making up the SDFs, and the integration of conservation plans into the Gert Sibande local municipalities SDFs, using geographic information systems (GIS) techniques. Biodiversity priorities were considered in the SDFs, and biodiversity conservation maps were integrated in the SDF. However, much of this integration can be credited to the outsourced service providers (consultants) who assist municipalities to develop the SDFs, as opposed to the land-use planners within government themselves. In chapter 3, I conducted interviews with the local municipality land-use planners, in order to gain insight into the extent to which they consider biodiversity priorities, and their use of conservation plans, during daily implementation/compliance processes. The consideration of biodiversity priorities, and the use of biodiversity conservation products, was largely inadequate during daily compliance processes. Another key finding was that there were still human capacity and financial constraints at the local level that prevented the proper and effective functioning of municipal government. Increased competency, and awareness about the importance of integrating biodiversity into local land-use planning, must be raised at local government, especially amongst local land-use planners. The findings of this study have implications for local level biodiversity conservation. A better understanding of the barriers to mainstreaming biodiversity into land-use planning is required by both land-use planners and conservation planners. Resolving these barriers could prevent biodiversity loss and improve biodiversity mainstreaming. At a broader scale, the insufficient use of conservation planning products in local government can have a major impact on efforts to achieve sustainable development goals, and the CBD objectives.

We here respond to Nunez et al. (Reg Environ Chang 20:39, 2020), recently published in Regional Environmental Change. Nunez et al. project biodiversity responses to land-use and climate change in Central Asia. Their projections are based on scenarios of changing socio-economic and environmental conditions for the years 2040, 2070, and 2100. We suggest that the predicted magnitude of biodiversity loss might be biased high, due to four shortfalls in the data used and the methods employed. These are (i) the use of an inadequate measure of “biodiversity intactness,” (ii) a failure to acknowledge for large spatial variation in land-use trends across the five considered Central Asian countries, (iii) the assumption of a strictly linear, negative relationship between livestock grazing intensity and the abundance of animals and plants, and (iv) the extrapolation of grazing-related biodiversity responses into areas of cropland. We conclude that future scenarios of biodiversity response to regional environmental change in Central Asia will benefit from using regional, not global, spatial data on livestock distribution and land-use patterns. The use of extra-regional data on the relationships between biodiversity and land-use or climate should be avoided.

Biodiversity models make an important contribution to our understanding of global biodiversity changes. The effects of different land uses vary across ecosystem types, yet most broad-scale models have failed to account for this variation. The effects of land use may be different in systems characterized by low water availability because of the unusual conditions within these systems. Drylands are expanding, currently occupying over 40% of the terrestrial land, while Mediterranean systems are highly endangered biodiversity hotspots. However, the impact of land use on biodiversity in these biomes is yet to be assessed. Using a database of local biodiversity surveys, we assess the effects of land use on biodiversity in the world’s drylands and Mediterranean ecosystems. We compare the average species richness, total abundance, species diversity, ecological dominance, endemism rates, and compositional turnover across different land uses. In drylands, there was a strong turnover in species composition in disturbed land uses compared with undisturbed natural habitat (primary vegetation), but other measures of biodiversity did not respond significantly. However, it is important to note that the sample size for drylands was very low, a gap which should be filled promptly. Mediterranean environments showed a very high sensitivity of biodiversity to land uses. In this biome, even habitat recovering after past disturbance (secondary vegetation) had substantially reduced biodiversity and altered community composition compared with primary vegetation. In an effort to maintain original biodiversity and the ecosystem functions it supports within Mediterranean biomes, conservation measures should therefore prioritize the preservation of remaining primary vegetation.

Pressures on freshwater ecosystems are mainly human induced and driven by land use and climate change. We develop an empirical framework to estimate the impacts of land use (agriculture, forest, pasture, urban) and climate change on freshwater biodiversity, measured by a fish-based index, in France. Our estimation results reveal that rivers in areas with more intensive agriculture and steep pasture are associated with lower freshwater biodiversity compared with forest areas. Our simulations show that climate change will exacerbate these negative impacts through land use adaptation. We discuss how two command-and-control policies could help improving freshwater biodiversity and cope with the adverse effects of land use and climate change.

Human land use has caused substantial declines in global species richness. Evidence from different taxonomic groups and geographic regions suggests that land use does not equally impact all organisms within terrestrial ecological communities, and that different functional groups of species may respond differently. In particular, we expect large carnivores to decline more in disturbed land uses than other animal groups. We present the first global synthesis of responses to land use across functional groups using data from a wide set of animal species, including herbivores, omnivores, carnivores, fungivores and detritivores; and ranging in body mass from 2 × 10⁻⁶ g (an oribatid mite) to 3,825 kg (the African elephant). We show that the abundance of large endotherms, small ectotherms, carnivores and fungivores (although in the last case, not significantly) are reduced disproportionately in human land uses compared with the abundance of other functional groups. The results, suggesting that certain functional groups are consistently favoured over others in land used by humans, imply a substantial restructuring of ecological communities. Given that different functional groups make unique contributions to ecological processes, it is likely that there will be substantial impacts on the functioning of ecosystems. A free Plain Language Summary can be found within the Supporting Information of this article.

AIM: Climate and land‐use change, the greatest pressures on biodiversity, can directly influence each other. One key case is the impact land‐use change has on local climatic conditions: human‐altered areas are often warmer and drier than natural habitats. This can have multiple impacts on biodiversity and is a rapidly developing field of research. Here, we summarize the current state of understanding on the impact that local climatic changes have on biodiversity responses to land‐use change, in particular looking at whether human‐altered land uses favour species with certain climatic niches. LOCATION: Global. METHODS: We review studies that have identified links between species' climatic niches and the habitats/land‐use types they inhabit. We also critically discuss the methods used to explore this topic (such as the estimation of fundamental vs. realized climatic niches), identify key knowledge gaps by reference to related macroecological literature and make suggestions for further work. RESULTS: Assemblages of vertebrate and invertebrate species in numerous human‐dominated land uses have been found to have higher proportions of individuals affiliated with higher temperatures and lower precipitation levels than assemblages within natural habitats. However, uncertainty surrounds the mechanisms that underlie these observed differences between communities across land‐use types, and it remains unexplored as to whether these trends differ geographically or taxonomically. MAIN CONCLUSION: Shifts are being observed within human‐altered land uses to communities with, on average, warmer and drier climatic niches. A better understanding of the effects of local climatic changes associated with land‐use change will enhance our ability to predict future impacts on biodiversity, identify the species most at risk from interactions between climate and land‐use change and set up suitable management and conservation plans.

Land-use change is currently the main driver of biodiversity loss. Projections of land-use change are often used to estimate potential impacts on biodiversity of future pathways of human development. However, such analyses frequently neglect that species can persist in human-modified habitats. Our aim was to estimate changes in biodiversity, considering affinities for multiple habitats, for three different land-use scenarios. Two scenarios focused on more sustainable trajectories of land-use change, based on either technological improvements (Pathway A) or societal changes (Pathway B), and the third reflected the historical or business-as-usual trends (Pathway 0). Using Portugal as a case study, we produced spatially-explicit projections of land-use change based on these pathways, and then we assessed the resulting changes in bird species richness and composition projected to occur by 2050 in each of the scenarios. By 2050, alpha and gamma diversity were projected to decrease, relative to 2010, in Pathway 0 and increase in Pathways A and B. However, different pathways favored different species groups, and presented strong regional differences. In the technological improvement pathway, loss of extensive agricultural areas led to an increase in both natural and extensive forest areas. In this pathway, forest species increase at the expense of farmland species, while in the societal change pathway the reverse occurs, as extensive agricultural areas were projected to increase. We show that while multiple positive pathways (A and B) for biodiversity can be envisioned, they will lead to differential impacts on biodiversity depending on the transformational changes in place and the regional socio-economic context. Our results suggest that considering compositional aspects of biodiversity can be critical in choosing the appropriate regional land-use policies.

Human‐induced global change dramatically alters individual aspects of river biodiversity, such as taxonomic, phylogenetic or functional diversity, and is predicted to lead to losses of associated ecosystem functions. Understanding these losses and dependencies are critical to human well‐being. Until now, however, most studies have only looked either at individual organismal groups or single functions, and little is known on the effect of human activities on multitrophic biodiversity and on ecosystem multifunctionality in riverine ecosystem. Here we profiled biodiversity from bacteria to invertebrates based on environmental DNA (hereafter, ‘eDNA’) samples across a major river catchment in China, and analysed their dependencies with multiple ecosystem functions, especially linked to C/N/P‐cycling. Firstly, we found a spatial cross‐taxon congruence pattern of communities' structure in the network of the Shaying river, which was related to strong environmental filtering due to human land use. Secondly, human land use explained the decline of multitrophic and multifaceted biodiversity and ecosystem functions, but increased functional redundancy in the riverine ecosystem. Thirdly, biodiversity and ecosystem function relationships at an integrative level showed a concave‐up (non‐saturating) shape. Finally, structural equation modeling suggested that land use affects ecosystem functions through biodiversity‐mediated pathways, including biodiversity loss and altered community interdependence in multitrophic groups. Our study highlights the value of a complete and inclusive assessment of biodiversity and ecosystem functions for an integrated land‐use management of riverine ecosystems.

The Paris Agreement to keep global temperature increase to well-below 2 °C and to pursue efforts to limit it to 1.5 °C requires to formulate ambitious climate-change mitigation scenarios to reduce CO2 emissions and to enhance carbon sequestration. These scenarios likely require significant land-use change. Failing to mitigate climate change will result in an unprecedented warming with significant biodiversity loss. The mitigation potential on land is high. However, how land-based mitigation options potentially affect biodiversity is poorly understood. Some land-based mitigation options could also counter the biodiversity loss. Here we reviewed the recently scientific literature to assess twenty land-based mitigation options that are implemented in different mitigation pathways to comply with the Paris Agreement for their biodiversity impacts by using the Mean Species Abundance (MSALU) indicator for land use. We showed the likely land-use transition and potential MSALU changes for each option, compared their carbon sequestration opportunities (tC per ha) and assessed the resulting biodiversity change in two case scenarios. Our results showed that most options benefit biodiversity. Reforestation of cultivated and managed areas together with restoration of wetlands deliver the largest MSALU increases, if land is allowed to reach a mature state over time. A quarter of the assessed options, including intensification of agricultural areas and bioenergy with carbon capture and storage, decreased MSALU. Options, such as afforestation and reduced deforestation, either positively or negatively affected MSALU. This depends on their local implementation and adopted forest-conservation schemes. Comparing the different options showed that avoiding deforestation by implementing agroforestry at the expense of pastures delivered both the largest MSALU increases and the highest carbon sequestration opportunities. However, agroforestry that leads to deforestation, enhanced carbon sequestration slightly but with a marginal MSALU increase. This stresses the importance of avoiding forest conversion. Our study advances the understanding on current and future benefits and adverse effects of land-based mitigation options on biodiversity. This certainly helps biodiversity conservation and determines the regions with large land-based mitigation potential.