Predicting biodiversity dynamics of grasslands under global change: the role of long-term manipulations of climate.

Part 1 Patterns and determinants of climate and landscape change: scenarios of global warming, Stephen H. Schneider evaluating landscape change - patterns of worldwide deforestation and local fragmentation, Martha J. Groom and Nathan Schumaker population and community processes in the response of terrestrial ecosystems to global change, David S. Schimel. Part 2 Physiology and population responses to environmental change: terrestrial vegetation and climate change - integrating models and experiments, Stephen W. Pacala and George C. Hurtt plant defense, herbivory, and climate change, Matthew P. Ayres population responses to environmental change - operative environments, physiologically structured models, and population dynamics, Arthur E. Dunham climate change and ecological interactions, Anthony R. Ives and George Gilchrist individual-based models for predicting effects of global change, William W. Murdoch. Part 3 Evolutionary responses to environmental change: evolutionary genetics and climatic change - will animals adapt to global warming?, Ary A. Hoffmann and Mark W. Blows evolutionary responses of plants to global change, Monica A. Gever and Todd E. Dawson the evolutionary dynamics of fragmented plant populations, Kent S. Holsinger genetic consequences of extinction and recolonization in fragmented habitats, David E. McCauley evolution and extinction in response to environmental change, Michael Lynch and Russell Lande global change - lessons from and for evolutionary biology, Joseph Travis and Douglas J. Futuyma. Part 4 Community responses to environmental change: species dynamics and global environmental change - a perspective from ecosystem experiments, Stephen R. Carpenter, et al effects of global climate change on North American birds and their communities, Terry L. Root implications of climate change for stream communities, Nancy B. Grimm paleoecological perspectives on modeling broad-scale responses to global change, James S. Clark carbon dioxide limitation and potential direct effects of its accumulation on plant communities, David Tilman a salty and salutary perspective on global change, Robert T. Paine forecasting ecological responses to global change - the need for large-scale comparative studies, Michael L. Pace. Part 5 Landscape change and habitat fragmentation: species invasions and deletions - community effects and responses to climate and habitat change, David M. Lodge species diversity, spatial scale, and global change, Susan Harrison effects of global change on the dynamics of insect host-parasitoid interactions, M.P. Hassell, et al conservation planning for species occupying fragmented landscapes - the case of the Northern Spotted Owl, Kevin McKelvey, et al part contents.

Changing climate could affect the functioning of grassland ecosystems through variation in climate forcings and by altering the interactions of forcings with ecological processes. Both the short and long-term effects of changing forcings and ecosystem interactions are a critical part of future impacts to ecosystem ecology and hydrology. To explore these interactions and identify possible characteristics of climate change impacts to mesic grasslands, we employ a low-dimensional modeling framework to assess the IPCC A1B scenario projections for the Central Plains of the United States; forcings include increased precipitation variability, increased potential evaporation, and earlier growing season onset. These forcings are also evaluated by simulations of vegetation photosynthetic capacity to explore the seasonal characteristics of the vegetation carbon assimilation response for species at the Konza Prairie in North Central Kansas, USA. The climate change simulations show decreases in mean annual soil moisture and and carbon assimilation and increased variation in water and carbon fluxes during the growing season. Simulations of the vegetation response show increased variation at the species-level instead of at a larger class scale, with important heterogeneity in how individual species respond to climate forcings. Understanding the drivers and relationships behind these ecosystem responses is important for understanding the likely scale of climate change impacts and for exploring the mechanisms shaping growing season dynamics in grassland ecosystems.

Climate change is a security problem in as much as the kinds of environmental changes that may result pose risks to peace and development. However, responsibilities for the causes of climate change, vulnerability to its effects, and capacity to solve the problem, are not equally distributed between countries, classes and cultures. There is no uniformity in the geopolitics of climate change, and this impedes solutions.

This special virtual issue of Plant Ecology draws together 14 papers on climate change published in the journal over the past 5 years. It encompasses a range of ecosystems and species, and issues relating to potential climate change effects on plants and plant communities. The potential impacts of global climate change on the distribution of species, and the distribution, structure and function of communities in the 21st century have been the subject of an everincreasing scientific literature over the past two decades (Parry 2007). Recent global analyses show that anthropogenic climate change is already affecting species and ecosystems and will continue to do so, with changes in the phenology, distribution and abundance of plants and animals reported for marine, freshwater and terrestrial plants and animals. Measured changes are heavily biased in the directions predicted under global warming scenarios and include earlier timing of spring events such as flowering, bud burst and egg laying, and latitudinal and altitudinal shifts in species ranges (Parmesan 2006). The magnitude and rate of on-going climate change, combined with other stressors, may exceed the adaptive capacity of species and resilience of ecosystems. In addition, changing climate combined with current, and future altered, disturbance regimes may lead to exacerbated rates of range contraction and extinction in plant species unable to maintain contact with suitable habitat through dispersal (Westerling et al. 2011; Moritz et al. 2012). Changes to ecosystems may include impoverished species mixes, simplified ecosystem structure and function, and greater vulnerability to invasive species (Malcolm et al. 2006; Midgley and Thuiller 2007; Keeley and Brennan 2012). Three key conclusions from the 2007 International Panel on Climate Change (Parry 2007) highlight the threat that anthropogenic climate change poses for global plant biodiversity: (1) Resilience of many ecosystems is likely to be exceeded by the combination of climate change, associated disturbances (e.g. wildfire) and other global change drivers. (2) Increases in global temperature of more than 1.5–2.5 C and rising atmospheric CO2 concentrations are projected to cause major changes in ecosystem structure, function and species interactions. (3) 2–30 % of plant species globally are at increased risk of extinction. Many studies on the potential impacts of climate change on plant and animal species have used bioclimatic envelope models which predict the future distribution of species using the correlation of their present range to present-day climate parameters, and the future geographic distribution of these climates based on a range of possible climate futures as described in various GCMs (e.g. Thuiller et al. 2005). Pearson and Dawson (2003) have highlighted the shortcomings of this approach as it ignores factors N. J. Enright (&) Murdoch University School of Veterinary and Life Sciences, Murdoch, Australia e-mail: N.Enright@murdoch.edu.au

The current situation and trend of land ecological security evaluation from the perspective of global change

Climate and land-use change are key drivers of global change. Full-factorial field experiments in which both drivers are manipulated are essential to understand and predict their potentially interactive effects on the structure and functioning of grassland ecosystems. Here, we present 8 years of data on grassland dynamics from the Global Change Experimental Facility in Central Germany. On large experimental plots, temperature and seasonal patterns of precipitation are manipulated by superimposing regional climate model projections onto background climate variability. Climate manipulation is factorially crossed with agricultural land-use scenarios, including intensively used meadows and extensively used (i.e., low-intensity) meadows and pastures. Inter-annual variation of background climate during our study years was high, including three of the driest years on record for our region. The effects of this temporal variability far exceeded the effects of the experimentally imposed climate change on plant species diversity and productivity, especially in the intensively used grasslands sown with only a few grass cultivars. These changes in productivity and diversity in response to alterations in climate were due to immigrant species replacing the target forage cultivars. This shift from forage cultivars to immigrant species may impose additional economic costs in terms of a decreasing forage value and the need for more frequent management measures. In contrast, the extensively used grasslands showed weaker responses to both experimentally manipulated future climate and inter-annual climate variability, suggesting that these diverse grasslands are more resistant to climate change than intensively used, species-poor grasslands. We therefore conclude that a lower management intensity of agricultural grasslands, associated with a higher plant diversity, can stabilize primary productivity under climate change.

Global climate change is reshaping ecosystems across the world. With rising temperatures, altered precipitation patterns, and an increasing frequency of extreme weather events, the world is experiencing unprecedented environmental shifts. In 2024, global temperatures have risen 1.63 °C above pre-industrial levels, surpassing the 1.5 °C target outlined in global climate agreements. Atmospheric CO₂ concentrations had reached historic highs, exceeding 422 ppm, constituting the greenhouse effect and accelerating these climate changes. The shifts in climate dynamics are not just abstract figures—they translate directly into changes on the ground, altering species distributions, vegetation patterns, and ecosystem structures. One of the most immediate and visible consequences of climate change is the increasing severity and frequency of regional wildfires. Wildfires are not only a product of changing climate conditions but also active drivers of ecological change. In 2021 alone, wildfires emitted an estimated 1.76 billion tonnes of carbon into the atmosphere, contributing to a feedback loop that intensifies global warming. These fires disrupt ecosystem services, threaten biodiversity, and challenge land managers and policymakers tasked with maintaining ecosystem resilience. South Africa is no exception, with its diverse landscapes and ecosystems that are particularly sensitive to shifts in climate and fire regimes. South Africa’s unique biomes—spanning grasslands, savannas, and the arid Nama-Karoo—are renowned for their biodiversity and critical role in ecosystem services. A delicate balance of climate, vegetation, and fire dynamics shapes these ecosystems. Yet, this balance is being disrupted by shifting rainfall patterns, recurring droughts, and rising temperatures. Vegetation dynamics and water availability are changing, putting ecosystems under stress and threatening the resources and services upon which both nature and people depend. Despite the urgency of these challenges, our understanding of South Africa’s ecosystems and their responses to these environmental pressures remains limited. This thesis set out to address these gaps, aiming to improve our understanding of the drivers shaping vegetation biomes and net primary production (NPP) while examining the intricate interplay between fire, vegetation, and climate. The Dynamic Global Vegetation Model (DGVM) provides an ideal tool for analysing these complex interactions. DGVMs are increasingly becoming important tools to advance ecosystem understanding of the complex interplay of vegetation, climate, and atmospheric processes and predict potential global changes. These models simulate key ecophysiological processes, such as photosynthesis, plant and soil respiration, carbon allocation, plant growth, competition between plant types for resources (commonly light and water, increasingly also nutrients) and disturbances such as fire. By capturing ecosystem responses to changing climate conditions and the feedback from ecosystems on climate—particularly through the terrestrial carbon cycle—DGVMs offer valuable insights into shifts in vegetation patterns, carbon dynamics, and fire regimes and support climate adaptation and mitigation efforts. The primary strength of DGVMs lies in their ability to map processes based on ecological and physical principles. They are powerful in quantifying spatial and temporal variations in ecosystem carbon fluxes and analysing the underlying mechanisms driving vegetation dynamics at large scales. DGVMs effectively explore interactions among ecosystem processes under future climatic conditions, elevated CO₂ levels, nitrogen deposition, land-use changes, and soil variations. Driven by climate and environmental data (e.g., soil properties and nutrient deposition) from historical observations or future projections, DGVMs provide a comprehensive framework for studying ecosystem responses in a changing world. Net primary production is a fundamental measure of ecosystem productivity, representing the balance between carbon absorbed through photosynthesis and carbon released through plant respiration. NPP underpins the resource supply for virtually all life on Earth, making it an essential variable for understanding ecosystem health and resilience. Robust projections of NPP are critical for managing the challenges posed by climate change to agriculture, forestry, water systems, and biodiversity. However, to develop reliable projections, we must first establish a solid understanding of the current dynamics and drivers of NPP.

Water sprays from an open fire hydrant in Brooklyn, New York, in the midst of a July 2010 heat wave that affected much of the eastern United States.In 2007 the New York City Department of Environmental Protection first teamed up with Alianza Dominicana, a Washington Heights community organization, to educate city residents about the appropriate use of fire hydrants and other ways

Identifying the drivers of ecosystem dynamics, and how responses vary spatially and temporally, is a critical challenge in the face of global change. Grasslands in sub‐Saharan Africa are vital ecosystems supporting biodiversity, carbon storage, and livelihoods through grazing. However, despite their importance, the processes driving change in these systems remain poorly understood, as cross‐scale interactions among drivers produce complex, context‐dependent dynamics that vary across space and time. This is particularly relevant for woody vegetation dynamics, which are often linked to degradation processes (e.g., woody encroachment), with consequences for biodiversity, forage availability, and fire regimes. Here, we used satellite data and structural equation models to investigate the effects of rainfall, temperature, fire, and population density on woody vegetation dynamics in four African grassland regions (the Sahel grasslands, Greater Karoo and Kalahari drylands, Southeast African subtropical grasslands, and Madagascar) during 1997–2016. Across all regions, rainfall was consistently positively correlated with increased woody vegetation, while higher temperatures were associated with decreased woody vegetation, suggesting that water availability promotes woody plant growth, whereas rising aridity limits it. Unexpectedly, fire had a negative effect on woody cover only in the Greater Karoo and Kalahari drylands, while in Madagascar, higher temperatures and greater population density reduced fire; yet these relationships did not translate into significant indirect effects on woody vegetation. These findings illustrate the complex ways by which environmental and anthropogenic drivers shape woody vegetation dynamics in grasslands across sub‐Saharan Africa. Compared to savannas, fire plays a weaker and more region‐specific role in grasslands, where its feedback with woody cover is less consistent. The opposing effects of rainfall and temperature may currently constrain woody expansion, but climate change could disrupt this balance and further weaken fire's limited regulatory role. These differences highlight the need for management strategies tailored to the distinct climate–vegetation dynamics of grassland systems.

Collectif Argos: Climate Refugees

Global environmental change and the uncertain fate of biodiversity

’s (2012) conclusion that observed climate change is comparableto projections, and in some cases exceeds projections, allows further inferences ifwe can quantify changing climate forcings and compare those with projections.The largest climate forcing is caused by well-mixed long-lived greenhouse gases.Here we illustrate trends of these gases and their climate forcings, and we discussimplications. We focus on quantities that are accurately measured, and we includecomparison with fixed scenarios, which helps reduce common misimpressionsabout how climate forcings are changing.Annual fossil fuel CO

Meta-analysis and its application in global change research

Agriculture production is directly dependent on climate change and weather. Possible changes in temperature, precipitation and CO2 concentration are expected to significantly impact crop growth and ultimately we lose our crop productivity and indirectly affect the sustainable food availability issue. The overall impact of climate change on worldwide food production is considered to be low to moderate with successful adaptation and adequate irrigation. Climate change has a serious impact on the availability of various resources on the earth especially water, which sustains life on this planet. The global food security situation and outlook remains delicately imbalanced amid surplus food production and the prevalence of hunger, due to the complex interplay of social, economic, and ecological factors that mediate food security outcomes at various human and institutional scales. Weather aberration poses complex challenges in terms of increased variability and risk for food producers and the energy and water sectors. Changes in the biosphere, biodiversity and natural resources are adversely affecting human health and quality of life. Throughout the 21st century, India is projected to experience warming above global level. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers. Longevity of heat waves across India has extended in recent years with warmer night temperatures and hotter days, and this trend is expected to continue. Strategic research priorities are outlined for a range of sectors that underpin global food security, including: agriculture, ecosystem services from agriculture, climate change, international trade, water management solutions, the water-energy-food security nexus, service delivery to smallholders and women farmers, and better governance models and regional priority setting. There is a need to look beyond agriculture and invest in affordable and suitable farm technologies if the problem of food insecurity is to be addressed in a sustainable manner. Introduction Globally, agriculture is one of the most vulnerable sectors to climate change. This vulnerability is relatively higher in India in view of the large population depending on agriculture and poor coping capabilities of small and marginal farmers. Impacts of climate change pose a serious threat to food security. “Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life” (World Food Summit, 1996). This definition gives rise to four dimensions of food security: availability of food, accessibility (economically and physically), utilization (the way it is used and assimilated by the human body) and stability of these three dimensions. According to the United Nations, in 2015, there are still 836 million people in the world living in extreme poverty (less than USD1.25/day) (UN, 2015). And according to the International Fund for Agricultural Development (IFAD), at least 70 percent of the very poor live in rural areas, most of them depending partly (or completely) on agriculture for their livelihoods. It is estimated that 500 million smallholder farms in the developing world are supporting almost 2 billion people, and in Asia and sub-Saharan Africa these small farms produce about 80 percent of the food consumed. Climate change threatens to reverse the progress made so far in the fight against hunger and malnutrition. As highlighted by the assessment report of the Intergovernmental Panel on Climate change (IPCC), climate change augments and intensifies risks to food security for the most vulnerable countries and populations. Few of the major risks induced by climate change, as identified by IPCC have direct consequences for food security (IPCC, 2007). These are mainly to loss of rural livelihoods and income, loss of marine and coastal ecosystems, livelihoods loss of terrestrial and inland water ecosystems and food insecurity (breakdown of food systems). Rural farmers, whose livelihood depends on the use of natural resources, are likely to bear the brunt of adverse impacts. Most of the crop simulation model runs and experiments under elevated temperature and carbon dioxide indicate that by 2030, a 3-7% decline in the yield of principal cereal crops like rice and wheat is likely in India by adoption of current production technologies. Global warming impacts growth, reproduction and yields of food and horticulture crops, increases crop water requirement, causes more soil erosion, increases thermal stress on animals leading to decreased milk yields and change the distribution and breeding season of fisheries. Fast changing climatic conditions, shrinking land, water and other natural resources with rapid growing population around the globe has put many challenges before us (Mukherjee, 2014). Food is going to be second most challenging issue for mankind in time to come. India will also begin to experience more seasonal variation in temperature with more warming in the winters than summers (Christensen et al., 2007). Climate change is posing a great threat to agriculture and food security in India and it's subcontinent. Water is the most critical agricultural input in India, as 55% of the total cultivated areas do not have irrigation facilities. Currently we are able to secure food supplies under these varying conditions. Under the threat of climate variability, our food grain production system becomes quite comfortable and easily accessible for local people. India's food grain production is estimated to rise 2 per cent in 2020-21 crop years to an all-time high of 303.34 million tonnes on better output of rice, wheat, pulse and coarse cereals amid good monsoon rains last year. In the 2019-20 crop year, the country's food grain output (comprising wheat, rice, pulses and coarse cereals) stood at a record 297.5 million tonnes (MT). Releasing the second advance estimates for 2020-21 crop year, the agriculture ministry said foodgrain production is projected at a record 303.34 MT. As per the data, rice production is pegged at record 120.32 MT as against 118.87 MT in the previous year. Wheat production is estimated to rise to a record 109.24 MT in 2020-21 from 107.86 MT in the previous year, while output of coarse cereals is likely to increase to 49.36 MT from 47.75 MT. Pulses output is seen at 24.42 MT, up from 23.03 MT in 2019-20 crop year. In the non-foodgrain category, the production of oilseeds is estimated at 37.31 MT in 2020-21 as against 33.22 MT in the previous year. Sugarcane production is pegged at 397.66 MT from 370.50 MT in the previous year, while cotton output is expected to be higher at 36.54 million bales (170 kg each) from 36.07. This production figure seem to be sufficient for current population, but we need to improve more and more with vertical farming and advance agronomic and crop improvement tools for future burgeoning population figure under the milieu of climate change issue. Our rural mass and tribal people have very limited resources and they sometime complete depend on forest microhabitat. To order to ensure food and nutritional security for growing population, a new strategy needs to be initiated for growing of crops in changing climatic condition. The country has a large pool of underutilized or underexploited fruit or cereals crops which have enormous potential for contributing to food security, nutrition, health, ecosystem sustainability under the changing climatic conditions, since they require little input, as they have inherent capabilities to withstand biotic and abiotic stress. Apart from the impacts on agronomic conditions of crop productions, climate change also affects the economy, food systems and wellbeing of the consumers (Abbade, 2017). Crop nutritional quality become very challenging, as we noticed that, zinc and iron deficiency is a serious global health problem in humans depending on cereal-diet and is largely prevalent in low-income countries like Sub-Saharan Africa, and South and South-east Asia. We report inefficiency of modern-bred cultivars of rice and wheat to sequester those essential nutrients in grains as the reason for such deficiency and prevalence (Debnath et al., 2021). Keeping in mind the crop yield and nutritional quality become very daunting task to our food security issue and this can overcome with the proper and time bound research in cognizance with the environment. Threat and challenges In recent years, climate change has become a debatable issue worldwide. South Asia will be one of the most adversely affected regions in terms of impacts of climate change on agricultural yield, economic activity and trading policies. Addressing climate change is central for global future food security and poverty alleviation. The approach would need to implement strategies linked with developmental plans to enhance its adaptive capacity in terms of climate resilience and mitigation. Over time, there has been a visible shift in the global climate change initiative towards adaptation. Adaptation can complement mitigation as a cost-effective strategy to reduce climate change risks. The impact of climate change is projected to have different effects across societies and countries. Mitigation and adaptation actions can, if appropriately designed, advance sustainable development and equity both within and across countries and between generations. One approach to balancing the attention on adaptation and mitigation strategies is to compare the costs and benefits of both the strategies. The most imminent change is the increase in the atmospheric temperatures due to increase levels of GHGs (Green House Gases) i.e. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and chlorofluorocarbons (CFCs) etc into the atmosphere. The global mean annual temperatures at the end of the 20th

razilian crop production has managed to grow expressively in the last 15 years with relatively little conversion of natural vegetation. Deforestation in the major Brazilian biomes however is still far from zero, and rates have been going up with the recent dismantling of public environmental governance (EG). Deforestation leads to changes in regional climate, which along with global climate change affects crop yields, often negatively. EG can benefit production by minimizing these effects. This thesis investigates how interactions between deforestation-induced and global climate change can affect Brazilian double cropping systems. These systems in Brazil play an important role on global grain production. Although modelling studies have suggested that they can be severely affected by global climate change, there’s little empirical understanding of their sensitivity to climate. Chapter 1 examines how past climate variability affected municipality-level statistics of soybeans and second crop maize yields and double cropping adoption, and evaluate the impacts of projected global changes in climate. Double cropping in parts of Brazil with strong precipitation seasonality is more likely to occur when the rainy season is larger than 200 days, with no DC in municipality-years below 150 days. CMIP6 models project years with the rainy season shorter than 200 days to be more likely by 2035-2050 under the SSP2-4.5 scenario in key double cropping regions in central Brazil. Soybean yields are projected to decline by ~12%, a result that is not substantially affected by yield model specification. Second crop maize yields are found to be less sensitive to changes in climate than soybeans, with no significant impacts on the country average. However, models that explicitly account for vapor pressure deficit project substantial (>10%) impacts on second crop maize yields in regions with projected rainy season shortening. Chapter 2 uses a fully coupled climate system model and the empirical yield models from Chapter 1 to evaluate how different plausible EG futures can affect the Brazilian production of soybeans and 2nd crop maize. We perform simulations combining two land use scenarios representing different levels of EG and two global climate change scenarios (RCPs 2.6 and 8.5). We find that soybean yields are negatively affected in all scenarios, but differences in EG can impact yields as much as differences in atmospheric composition (RCPs). Stronger environmental governance can prevent soybean production losses equivalent to 442-527 million USD year -1 in the Amazon and 670-1347 million USD year -1 in the Cerrado by 2050, up to 10% of projected production. Collectively, Brazilian soybean farmers have much to gain with better environmental governance and it would be in their interest to enforce and even extend private zero-deforestation agreements in the Amazon and Cerrado biomes. Keywords: Double cropping. Statistical crop model. Climate change. Brazil. Deforestation. Biogeophysical climate change. Land use and land cover change. Earth system models