Guy F Midgley

Stellenbosch University | SUN · Department of Botany and Zoology

The ability to validate satellite observations with ground‐based data sets is vital for the spatiotemporal assessment of productivity trends in semi‐arid ecosystems. Modeling ecosystem scale parameters such as gross primary production (GPP) with the combination of satellite and ground‐based data however requires a comprehensive understanding of the...

We aim to explore what processes dominate community assembly of dragonflies (Odonata: Anisoptera) and damselflies (Odonata: Zygoptera) by differentiating the environmental and geographical drivers behind compositional turnover of narrow‐ranged versus widespread species. In this way, we further aim to describe patterns of species incidence and compo...

Biomes are regional to global vegetation formations characterised by their structure and functioning. These formations are thus valuable for both quantifying ecological status at sub-regional spatial scales and defining broad adaptive management strategies. Global changes are altering both the structure and the functioning of biomes globally, and w...

Ecosystems in southern Africa are threatened by numerous global change forces, with climate change being a major threat to the region. Many climate change impacts and environmental-based mitigation and adaptation options remain poorly researched in this globally important biodiversity hotspot. This book is a collection of chapters covering research...

The southern African subcontinent and its surrounding oceans accommodate globally unique ecoregions, characterized by exceptional biodiversity and endemism. This diversity is shaped by extended and steep physical gradients or environmental discontinuities found in both ocean and terrestrial biomes. The region’s biodiversity has historically been th...

Southern Africa is a climate change hotspot with projected warming and drying trends amplifying stresses in a naturally warm, dry and water-stressed region. Despite model-projected uncertainty in rainfall change over the eastern escarpment of South Africa, strong model agreement in projections indicates that southern African is likely to become gen...

In this chapter, we highlight the importance and value of key Environmental Research Infrastructures, and how these can act as anchor points for long-term environmental observations and facilitate interdisciplinary environmental research. We briefly summarize the development of these efforts in South and southern Africa over the last three decades...

The sustainability of southern Africa’s natural and managed marine and terrestrial ecosystems is threatened by overuse, mismanagement, population pressures, degradation, and climate change. Counteracting unsustainable development requires a deep understanding of earth system processes and how these are affected by ongoing and anticipated global cha...

Semiarid South African ecosystems are managed for livestock production with different practices and intensities. Many studies have found grazing to be an important driver of vegetation change; however, its impacts on carbon fluxes remain poorly studied. Unsustainable management over the past 200 years has led to an increase of degraded areas and a...

SDG goal 17 seeks to strengthen global partnerships, especially between Global North and South. However, in research and development, experiences indicate a mismatch in expectations with perceived power, funding and workload imbalances, a situation derogated as ‘parachute science’ or ‘helicopter research’. The research programme SPACES seeks to enh...

The sustainability of southern Africa’s natural and managed marine and terrestrial ecosystems is threatened by overuse, mismanagement, population pressures, degradation, and climate change. Counteracting unsustainable development requires a deep understanding of earth system processes and how these are affected by ongoing and anticipated global cha...

Livestock use in semi-arid South African ecosystems has not been extensively studied in relation to the Net Ecosystem Exchange (NEE) of carbon dioxide (CO2). We present four years of measurements from twinned eddy-covariance towers in Nama-Karoo, South Africa, to investigate the carbon fluxes and the impact of grazing intensity on NEE. The design c...

SIGNIFICANCE: Carbon dioxide removal (CDR) negative emissions interventions are needed to steer the planet to a safe climate by the end of the century. In this Commentary, we frame the rationale and likely challenges for a regionally focused and coordinated CDR-centred science-policy platform with a global reach to support the opportunities and min...

Global agreement on 30×30 means an unprecedented last push to define how much nature will be left on the planet. At the same time that space for nature is being defined, climate change will be moving nature around. Species now on the move track climate change both on land and in the oceans, a process that is accelerating under dramatic new extreme...

Earth’s biodiversity and human societies face pollution, overconsumption of natural resources,urbanization, demographic shifts, social and economic inequalities, and habitat loss, many of whichare exacerbated by climate change. Here, we review links among climate, biodiversity, and society anddevelop a roadmap toward sustainability. These includeli...

The African penguin Spheniscus demersus, endemic to the coast of southern Africa, has suffered anthropogenic-driven population declines since 1900 and is now listed as Endangered on the IUCN Red List. Conservation efforts currently underway are informed by the species’ adaptive response with respect to colonisation capacity and breeding success, vu...

Woody plant encroachment (WPE) has been found to alter ecosystem functioning and services in savannas. In rain-limited savannas, increasing woody cover can reduce streamflow and groundwater by altering evapotranspiration rates and rainfall partitioning , but the ecological relevance of this impact is not well known. This study quantified the altere...

The genus Vachellia (Fabaceae) has a pan-tropical distribution and numerous Vachellia species are currently observed to be expanding their indigenous ranges and/or are invasive. Most Vachellia species have the capacity to enhance nitrogen uptake via an N2-fixing rhizobial mutualism that manifests in specialized root nodule structures enabling the c...

The achievement of adaptation objectives will require increased investment with the increasing warming, but adaptation cost curves are not yet well quantified. We propose here that tipping points (sharp increases) in adaptation costs may emerge as key warming levels are exceeded, with important implications for policymakers and planners. We explore...

If trees minimize self‐shading, new foliage in shaded parts of the crown should remain minimal. However, many species have abundant foliage on short shoots inside their crown. In this paper, we test the hypothesis that short shoots allow trees to densify their foliage in self‐shaded parts of the crown thanks to reduced costs. Using 30 woody species...

South Africa is a mega-diverse country situated at the southern tip of Africa flanked by two unique marine systems, one cool and one warm. Species introductions to the region have also been diverse. Given the major and growing threat to biodiversity and ecosystem functioning from biological invasions, there has been significant research on this top...

CO2‐fertilisation is implicated in the widespread and significant woody encroachment of savannas due to CO2‐stimulated increases in below‐ground reserves that enhance sapling regrowth after fire. However, the effect of CO2 concentration ([CO2]) on tree responses to the other major disturbance in savannas, herbivory, is poorly understood. Herbivory...

Africa's protected areas (PAs) are the last stronghold of the continent's unique biodiversity, but they appear increasingly threatened by climate change, substantial human population growth, and land‐use change. Conservation planning is challenged by uncertainty about how strongly and where these drivers will interact over the next few decades. We...

The world is firmly cemented in a notitian age (Latin: notitia, meaning data) – drowning in data, yet thirsty for information and the synthesis of knowledge into understanding. As concerns over biodiversity declines escalate, the volume, diversity and speed at which new environmental and ecological data are generated has increased exponentially. Da...

South Africa is wrestling with increasing climate change impacts and how to respond. The 2022 IPCC Working Group II Report synthesises the latest evidence on climate change impacts, vulnerability and adaptation, and what this means for climate-resilient development. In this commentary, South African authors on the Report reflect on its key findings...

Conservation approaches to social-ecological systems have largely been informed by a framing of preserving nature for its instrumental societal benefits, often ignoring the complex relationship of humans and nature and how climate change might impact these. The Nature Futures Framework (NFF) was developed by the Task Force on scenarios and models o...

Aloidendron dichotomum appears to be undergoing the early stages of a range shift in response to anthropogenic climate change in south-western Africa. High mortality has been recorded in warmer populations, while population expansions have been recorded in cooler poleward parts of its range. This study aimed to determine the key environmental contr...

The Working Group II contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive assessment of the scientific literature relevant to climate change impacts, adaptation and vulnerability. The report recognizes the interactions of climate, ecosystems and biodiversity, and human societie...

Increases in the frequency and magnitudes of extreme events, attributed to anthropogenic climate change by WGI (IPCC, 2021a), are now causing profound negative effects across all realms of the world (marine, terrestrial, freshwater and polar) (medium confidence) (Fox-Kemper et al., 2021; Seneviratne et al., 2021) (Sections 2.3.1, 2.3.2, 2.3.3.5, 2....

Extreme changes in temperature, rainfall and wind regimes have been correlated with plant species range expansion upslope on sub‐Antarctic islands. Ongoing climatic changes are expected to continue driving changes in species distributions globally, but niche specialisations may limit the capacity for range shifts. We hypothesised that non‐climatic...

There is a lack of long-term greenhouse gas (GHG) measurement infrastructures in Africa. This limits our understanding of the temporal dynamics of the biosphere-atmosphere exchange of carbon in response to climate change. Where relevant infrastructures have been established in externally funded research projects, they have often not been successful...

Climate change is challenging the ability of protected areas (PAs) to meet their objectives. To improve PA planning, we developed a framework for assessing PA vulnerability to climate change based on consideration of potential climate change impacts on species and their habitats and resource use. Furthermore, the capacity of PAs to adapt to these c...

Rainfall-runoff models are frequently used for assessing climate risks by predicting changes in streamflow and other hydrological processes due to anticipated anthropogenic climate change, climate variability, and land management. Historical observations are commonly used to calibrate empirically the performance of conceptual hydrological mechanism...

The two most urgent and interlinked environmental challenges humanity faces are climate change and biodiversity loss. We are entering a pivotal decade for both the international biodiversity and climate change agendas with the sharpening of ambitious strategies and targets by the Convention on Biological Diversity and the United Nations Framework C...

A globally rare climatic regime with seasonally predictable winter rainfall and summer dryness, relatively stable for millennia, characterises the Succulent Karoo Biome of southwestern Africa. This regime is likely facilitated extraordinary species richness and endemism across multiple taxa in plant and animal kingdoms. Endemism in leaf-succulent f...

Understanding the impacts of climate change requires the development of hydrological modelling tools. However, data scarcity hinders model application, performance, process simulation and uncertainty, especially for Sub-Saharan Africa. In this study, a multi-catchment approach was used to assess hydrological process variability in the Western Cape...

Using soil-moisture drought indices to determine agricultural droughts for semi-arid Mediterranean Southern Africa

Aim Climate change is expected to cause large shifts in species assemblages such as dragonflies and damselflies (Insecta: Odonata). Here, we assess the influence of environmental drivers of turnover on Odonata assemblages. Secondly, we map the predicted spatial variation in species composition, first as a gradient of assemblage similarity, and then...

Concerns have been raised about attribution of species range shifts to anthropogenic climate change. Species paleo-range projections are emerging as a means to broaden understanding of range shifts and could be applied to assist in attribution. Apparent recent range contraction in the Quiver Tree (Aloidendron dichotomum (Masson) Klopper and Gideon...

In the context of ongoing climate change and increasing population, there is an urgent need to optimize the water consumption of surface and groundwater in agricultural production. In recent years, intensive irrigated viticulture and horticulture have faced increasing demand pressure in many water-limited areas including the Western Cape Province i...

Planning for future water resource management in a warming climate is confounded when an expectation of increasing evaporation from open water surfaces with global warming is contradicted by observations of secular declines of pan evaporation. Decreasing pan evaporation has been observed globally – a trend which has been attributed variously to dec...

This policy brief explores the potential of the Future Climate For Africa (FCFA) research programme to support work on climate change, impacts and adaptation in tropical and sub-tropical sub-Saharan Africa. It points out insights developed from advances made by FCFA-sponsored climate science on what stimulates climate processes over tropical and...

The Scientific Outcome was produced by participants in the first-ever IPCC-IPBES co-sponsored workshop which took place in December 2020. This workshop is placed in the context of recent international agreements including the Paris Agreement, the Strategic Plan for Biodiversity 2011-2020 and ongoing preparation for the post-2020 global biodiversi...

Species in the genus Vachellia (Fabaceae) have a global tropical and sub-tropical distribution. Numerous Vachellia species are currently observed to be expanding their indigenous ranges and increasing in dominance globally, suggesting an overarching driver. Most Vachellia species enhance nitrogen uptake mutualistically via specialized root nodule s...

Climate change affects life at global scales and across systems but is of special concern in areas that are disproportionately rich in biological diversity and uniqueness. Using a meta-analytical approach, we analysed >8000 risk projections of the projected impact of climate change on 273 areas of exceptional biodiversity, including terrestrial and...

A flexible use of the crassulacean acid metabolism (CAM) has been hypothesised to represent an intermediate stage along a C3 to full CAM evolutionary continuum, when relative contributions of C3 vs CAM metabolism are co‐determined by evolutionary history and prevailing environmental constraints. However, evidence for such eco‐evolutionary interdepe...

Community and invasion ecology have mostly grown independently. There is substantial overlap in the processes captured by different models in the two fields, and various frameworks have been developed to reduce this redundancy and synthesize information content. Despite broad recognition that community and invasion ecology are interconnected, a pro...

Climate change is causing species’ ranges to shift, many at unprecedented rates, all across the planet. This poses a challenge for planning and management of biodiversity conservation through area-based conservation, as conserved areas are fixed in place. However, nearly a decade of research shows that strategic planning for new conserved areas can...

Recent assessment reports by the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services IPBES) have highlighted the risks to humanity arising from the unsustainable use of natural resources. Thus far, land, freshwater, and ocean exploitation have been the chief caus...

Anthropogenic climate change is expected to impact ecosystem structure, biodiversity and ecosystem services in Africa profoundly. We used the adaptive Dynamic Global Vegetation Model (aDGVM), which was originally developed and tested for Africa, to quantify sources of uncertainties in simulated African potential natural vegetation towards the end o...

Biomes are constructs for organising knowledge on the structure and functioning of the world’s ecosystems, and serve as useful units for monitoring how the biosphere responds to anthropogenic drivers, including climate change. The current practice of delimiting biomes relies on expert knowledge. Recent studies have questioned the value of such biom...

Plants and vegetation play a critical—but largely unpredictable—role in global environmental changes due to the multitude of contributing processes at widely different spatial and temporal scales. In this Perspective, we explore approaches to master this complexity and improve our ability to predict vegetation dynamics by explicitly taking account...

Background and aims: Global plant trait datasets commonly identify trait relationships that are interpreted to reflect fundamental trade-offs associated with plant strategies, but often these trait relationships are not identified when evaluating them at smaller taxonomic and spatial scales. In this study we evaluate trait relationships measured o...

In this chapter, we assess how much research in South Africa has been directed towards biological invasions relative to other elements of global change. Using Web of Science, we systematically reviewed literature relevant to South African ecosystems published between 2000 and 2018 and relating to biological invasions, climate change, overharvesting...

The structure and function of vegetation in savannas is shaped by interactions between climate and disturbances like fire and herbivory. These disturbances can act as environmental filter on the species in an area, and can shape community composition and trait selection; therefore any change in disturbances can alter the future success of a species...

Limiting climate change to less than 2°C is the focus of international policy under the climate convention (UNFCCC), and is essential to preventing extinctions, a focus of the Convention on Biological Diversity (CBD). The post‐2020 biodiversity framework drafted by the CBD proposes conserving 30% of both land and oceans by 2030. However, the combin...

The time is now For decades, scientists have been raising calls for societal changes that will reduce our impacts on nature. Though much conservation has occurred, our natural environment continues to decline under the weight of our consumption. Humanity depends directly on the output of nature; thus, this decline will affect us, just as it does th...

The Cape Restionaceae species, an endemic of the Fynbos Biome, is threatened by urbanization, alien plant invasion, agricultural expansion, and groundwater extraction. This is further worsened by the semi-arid conditions and hydrological variability factors, which influences species niche dynamics. Therefore, it is important to assess and monitor t...

A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant diversity to quantify the fraction of Earth’s plant biodiversity that are rare. A large fraction, ~36...

Background: Plant-endophyte symbioses often revolve around nitrogen metabolism, and involve varying degrees of intimacy. Although evidence for vertical inheritance of nitrogen-fixing endophytic bacteria is increasing, it is confined mostly to crop plants, and to date no such system has been reported for geophytes. Methods: Bacterial endophytes asso...