Search

Flash droughts (FDs) have attracted widespread attention in recent years due to their sudden onset and rapid intensification with significant impacts on ecosystems, water resources, and agriculture. These features of FDs pose unique challenges for their forecast, monitoring, and mitigation. The impact of FDs on society can vary depending on several factors, such as the frequency of their occurrence, rate of intensification, and mean severity, which are not well understood and remain unclear specifically over India. This study developed a novel approach to quantitatively define FD based on the aridity index. This new approach was used to examine spatiotemporal characteristics (including trends) and triggers of FDs over 25 river basins across India from 1981 to 2021. The hydrometeorological conditions, including soil moisture percentiles, anomalies of precipitation, temperature, and vapor pressure deficit were investigated at different stages of FD. Results suggest that FDs with high intensification rates are more common in humid areas compared to subhumid and semiarid areas. Both precipitation and temperature are primary triggers of FDs over a major part of the study area. The individual effects of soil moisture and precipitation also act as a trigger across some regions (like northeast India and the Western Ghats). Additionally, atmospheric aridity can create conditions conducive to FDs, and when combined with depleted soil moisture, it can accelerate their rapid onset. Besides the scientific novelty, the findings of this study will facilitate policymakers to formulate effective strategies to mitigate the consequences of FDs on water resources and agriculture in India. Significance Statement: Flash droughts have attracted widespread attention due to their sudden onset and rapid intensification with significant impacts on multiple vectors. The impact of flash drought on society depends on their frequency, rate of intensification, and mean severity, which are not well understood and remain unclear specifically over India. This study develops a novel approach to quantitatively define flash drought based on the aridity index. This new approach is used to examine spatiotemporal characteristics and triggers of flash drought over 25 river basins across India from 1981 to 2021. Besides the scientific novelty, the findings of this study will facilitate policymakers to formulate effective strategies to mitigate the consequences of FDs on water resources and agriculture in India. [ABSTRACT FROM AUTHOR]

Phenological indicators (PI) are used to study changes to animal and plant behavior in response to seasonal cycles, and they can be useful to quantify the potential impacts of climate change on ecosystems. Here, multiple global climate models and emission scenarios are used to drive dynamically downscaled simulations using the WRF Model over the contiguous United States (CONUS). The wintertime dormancy of plants [chilling units (CU)], timing of spring onset [extended spring indices (SI)], and frequency of proceeding false springs are calculated from regional climate simulations covering historical (1995-2005) and future periods (2025-2100). Southern parts of the CONUS show projected CU decreases (inhibiting some plants from flowering or fruiting), while the northern CONUS experiences an increase (possibly causing plants to break dormancy too early, becoming vulnerable to disease or freezing). Spring advancement (earlier SI dates) is projected, with decadal trends ranging from approximately 1-4 days per decade over the CONUS, comparable to or exceeding those found in observational studies. Projected changes in risk of false spring (hard freezes following spring onset) vary across members of the ensemble and regions of the CONUS, but generally western parts of the CONUS are projected to experience increased risk of false springs. These projected changes to PI connote significant effects on cycles of plants, animals, and ecosystems, highlighting the importance of examining temperature changes during transitional seasons. SIGNIFICANCE STATEMENT: This study examines how phenological indicators, which track the life cycles of plants and animals, could change from 2025 to 2100 as simulated in a regional climate model over the contiguous United States. Chilling units quantify the presence of cooler weather that can benefit plants prior to their growing season. They are projected to decrease in the southern United States, possibly inhibiting agricultural production. Spring onset is projected to occur earlier in the year, advancing by 1-4 days on average over each future decade. Risk of false springs (damaging hard freezes after spring onset) increases in the western United States. Our findings highlight the need to understand effects of climate change during transitional seasons, which can impact agriculture and ecosystems. [ABSTRACT FROM AUTHOR]

As global mean temperature rises, extreme drought events are expected to increasingly affect regions of the United States that are crucial for agriculture, forestry, and natural ecology. A pressing need is to understand and anticipate the conditions under which extreme drought causes catastrophic failure to vegetation in these areas. To better predict drought impacts on ecosystems, we first must understand how specific drivers, namely, atmospheric aridity and soil water stress, affect land surface processes during the evolution of flash drought events. In this study, we evaluated when vapor pressure deficit (VPD) and soil moisture thresholds corresponding to photosynthetic shutdown were crossed during flash drought events across different climate zones and land surface characteristics in the United States. First, the Dynamic Canopy Biophysical Properties (DCBP) model was used to estimate the thresholds that define reduced photosynthesis by assimilating vegetation phenology data from theModerate Resolution Imaging Spectroradiometer (MODIS) to a predictive phenology model. Next, we characterized and quantified flash drought onset, intensity, and duration using the standardized evaporative stress ratio (SESR) and NLDAS-2 reanalysis. Once periods of flash drought were identified, we investigated how VPD and soil moisture coevolved across regions and plant functional types. Results demonstrate that croplands and grasslands tend to be more sensitive to soil water limitations than trees across different regions of the United States. We found that whether VPD or soil moisture was the primary driver of plant water stress during drought was largely region specific. The results of this work will help to inform land managers of early warning signals relevant for specific ecosystems under threat of flash drought events. [ABSTRACT FROM AUTHOR]

Abstract The spring dry season occurring in an arid region of the southwestern United States, which receives both winter storm track and summer monsoon precipitation, is investigated. Bimodal precipitation and vegetation growth provide an opportunity to assess multiple climate mechanisms and their impact on hydroclimate and ecosystems. We detect multiple shifts from wet to drier conditions in the observational record and land surface model output. Focusing on the recent dry period, a shift in the late 1990s resulted in earlier and greater spring soil moisture draw down, and later and reduced spring vegetation green-up, compared to a prior wet period (1979–97). A simple soil moisture balance model shows this shift is driven by changes in winter precipitation. The recent post-1999 dry period and an earlier one from 1948 to 1966 are both related to the cool tropics phase of Pacific decadal variability, which influences winter precipitation. In agreement with other studies for the southwestern United States, we find the recent drought cannot be explained in terms of precipitation alone, but also is due to the rising influence of temperature, thus highlighting the sensitivity of this region to warming temperatures. Future changes in the spring dry season will therefore be affected by how tropical decadal variability evolves, and also by emerging trends due to human-driven warming.

The teleconnection mechanisms associated with midlatitude climate dipoles are of high interest because of their potential broad impacts on ecological patterns and processes. A prominent example attracting increasing research interest is a summer (June–August) North American dipole (NAD), which drives continental-scale bird irruptions in the boreal forest (semiperiodic movements of large numbers of individual birds). Here, the NAD is objectively defined as a second principal component of 500-hPa geopotential height and is linked to two mechanisms: 1) Rossby waves associated with Madden–Julian oscillation (MJO) convection and 2) a pan-Pacific stationary Rossby wave triggered by East Asian monsoonal convection. The MJO mechanism relates to anomalously frequent occurrence of MJO phase 1 or 6, which are captured by the leading principal component of daily summer MJO phases (PCM1; accounting for 46% of the phase variance). In "nonuniform" MJO summers, defined as |PCM1| > 0.5, anomalously frequent phase 1 triggers positive NAD, and anomalously frequent phase 6 triggers negative NAD, yielding the correlation r(NAD, PCM1) = 0.55, p < 0.01. During "uniform" MJO summers, defined as |PCM1| ≤ 0.5, the effect of East Asian precipitation anomalies PEA becomes apparent, and r(NAD, PEA) = 0.49, p < 0.01. The impacts of PEA are largely masked during nonuniform MJO summers, meaning this subset of summers lacks a significant correlation between the NAD and PEA. Our interpretation is that uniformly distributed MJO allows monsoonal convection over the midlatitudes to modulate the NAD, whereas tropical convection anomalies associated with anomalously frequent MJO phases 1 and 6 overwhelm the extratropical teleconnection. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing interest in the impacts caused by the presence of microplastics (MP) in aquatic environments. The impacts of microalgae exposure to microplastics are still insufficiently investigated and further studies are needed to understand the possible outcomes. In addition, much of the literature has focused on the study of concentrations above those found naturally in the environment and in less toxic polymer matrices. Acrylonitrile-butadiene-styrene (ABS) plastics have a composition rich in additives and, so far, have been studied superficially. In the present study, two of the most commonly used green microalgae species in toxicity assays, Chlorella vulgaris and Raphidocelis subcapitata, were exposed to different concentrations of primary ABS-MP for a period of 6 days. Here, we observed physiological changes in cell growth and chlorophyll a content induced by the concentration and time of exposure to ABS-MP. The lowest concentration did not prove to be potentially toxic to cells, while the highest concentration was the most toxic. Primary consumers, such as microalgae, are essential for the proper functioning of entire ecosystems. Changes in these communities can lead to permanent damage to the communities of organisms at higher levels, so it is essential that their study be done carefully in the face of threats such as MP. Chlorella vulgaris and Raphidocelis subcapitata, were exposed to different concentrations of ABS microplastics during 6 days. We observed physiological changes in cell growth and chlorophyll content in response to the concentration and duration of exposure. [ABSTRACT FROM AUTHOR]

Strategies that demonstrate renewed potential to enhance both social and ecological systems are crucial in today's era of rapid urbanization. However, the approaches used to understand the impacts of such strategies sometimes favor social over environmental theory, or the opposite, but do not always consider both equally. Our study addresses this disconnect by exploring the role of urban agriculture (UA) as an alleviation and land management strategy in Mexico City (MC), Mexico. Our integrated design combined the ecosystem services framework, which was primarily used to assess material and nonmaterial benefits MC residents obtain from UA spaces and its associated vegetation, and the livelihoods framework, which was used to evaluate the relationship between UA and societal impacts. We used a mixed-method approach to quantify the amount of food produced, assess crop diversity, assess six distinct ecological processes linked to UA, identify cultural benefits, and conduct an evaluation of contributions to livelihood capitals. Our study documented the role of UA in supporting ecological processes, connecting humans to nature, and providing a supplemental source of income. However, a multitude of unintended outcomes are identified, such as trade-offs between different ecological processes, constraints in promoting formal education beyond agroecological knowledge, and an inability to fully elevate families out of poverty. Our integrated approach demonstrated how the ecosystem services and livelihoods frameworks can be used simultaneously to provide thorough assessments of socioecological systems, identifying outcomes that could go unnoticed without an interdisciplinary lens. [ABSTRACT FROM AUTHOR]

Coastal wetlands are ecotones interspaced by land and ocean and are among the most sensitive and vulnerable ecosystems worldwide. They are unique in hydrological, edaphic, atmospheric, and biological characteristics, and play important roles in maintaining the ecological security and ecosystem services of coastal zones. Arbuscular mycorrhizae (AM) are symbiont composed of plant roots and arbuscular mycorrhizal fungi (AMF), which are soil-borne microorganisms widely distributed in various habitats. Many previous studies on mycorrhiza have focused on terrestrial ecosystems while few on wetlands, especially coastal wetlands. We systematically reviewed previous relevant studies to explore the formation and functions of AM in coastal wetland ecosystems as well as the environmental factors that affect them. Habitat characteristics, morphological types, and species diversity of AMF in the coastal wetlands were summarized. Both responses of AMF to environmental factors during AM formation and the functions of AM in coastal wetlands were discussed. AMF are worldwide distributed in coastal wetland and are mainly limited by flooding, hypoxia, soil pH, salinity and the host plants identification. AMF play important roles in coastal wetlands, involving promoting nutrient uptake of host plants, improving the characteristics of rhizospheric soil, and enhancing plant resistance to salt and flooding stress. More comprehensive studies of AMF in vitro in coastal wetlands would be helpful for the conservation and restoration of coastal wetland ecosystems in the changing world. [ABSTRACT FROM AUTHOR]

Carnivore conservation translocations are assumed to provide numerous ecological benefits, including conservation of the translocated carnivores, regulation of prey species and restoration of ecosystems. Reviews of mammalian carnivore conservation translocations and resultant ecosystem effects have focussed on large carnivores. We reviewed global terrestrial carnivore conservation translocations across all taxa, including taxonomic bias, problems influencing their population establishment and their ecosystem effects.We obtained data from 536 conservation translocations of 54 species of terrestrial mammalian carnivore (order Carnivora and family Dasyuridae, 30 g–196 kg), comprising mostly Mustelidae, Canidae, and Felidae species. A third of all projects translocated carnivores into South Africa and a third into fenced reserves.Significant bias occurred relative to threat status, with over‐representation of Mustelidae and Canidae conservation translocations relative to the number of threatened species in each family. Additionally, conservation translocations of small carnivores were generally under‐represented compared to those of large carnivores.Seventeen percent of small carnivore conservation translocations failed, compared with 25% of large carnivore conservation translocations; failure was primarily due to reported anthropogenic mortality.Effects on resident prey species or ecosystems of carnivore conservation translocations were rarely investigated. We found no significant relationship between the carnivore family or size and effects on prey or ecosystems; however, prey impacts were frequently attributed to Felidae, and ecosystem effects were frequently attributed to Canidae and Felidae.Challenges to translocations of mammalian carnivores include threats to resident threatened prey species and difficulties in monitoring the ecological effects of carnivore conservation translocations. Poor postrelease monitoring and a lack of empirical studies remain persistent problems, contributing to the poor understanding of ecosystem effects following carnivore conservation translocations. [ABSTRACT FROM AUTHOR]

Context Coastal wetlands are ecotones interspaced by land and ocean and are among the most sensitive and vulnerable ecosystems worldwide. They are unique in hydrological, edaphic, atmospheric, and biological characteristics, and play important roles in maintaining the ecological security and ecosystem services of coastal zones. Arbuscular mycorrhizae (AM) are symbiont composed of plant roots and arbuscular mycorrhizal fungi (AMF), which are soil-borne microorganisms widely distributed in various habitats. Many previous studies on mycorrhiza have focused on terrestrial ecosystems while few on wetlands, especially coastal wetlands.Method We systematically reviewed previous relevant studies to explore the formation and functions of AM in coastal wetland ecosystems as well as the environmental factors that affect them. Habitat characteristics, morphological types, and species diversity of AMF in the coastal wetlands were summarized. Both responses of AMF to environmental factors during AM formation and the functions of AM in coastal wetlands were discussed.Result AMF are worldwide distributed in coastal wetland and are mainly limited by flooding, hypoxia, soil pH, salinity and the host plants identification. AMF play important roles in coastal wetlands, involving promoting nutrient uptake of host plants, improving the characteristics of rhizospheric soil, and enhancing plant resistance to salt and flooding stress.Conclusion More comprehensive studies of AMF in vitro in coastal wetlands would be helpful for the conservation and restoration of coastal wetland ecosystems in the changing world.

Despite a relatively low climate sensitivity indicated by atmospheric-only simulations with uniform sea surface temperature (SST) warming, GFDL's new climate model CM4.0 participating in CMIP6 and the seasonal-to-decadal prediction system SPEAR, both of which use an identical atmospheric model AM4.0, produce relatively high effective climate sensitivity (EffCS). The substantial increase in CM4.0's EffCS is found to be caused by additional positive forcing associated with the CO2 fertilization effect on vegetation, enhanced positive feedback due to stronger reduction in Southern Hemisphere (SH) sea ice concentration (SIC), and clouds whose feedback depends on SST warming patterns. Compared to a SPEAR run using a static vegetation model (SPEAR-SV), CM4.0 produces roughly 30% larger EffCS, among which roughly 1/3 of the increase is due to dynamical vegetation with the rest due primarily to changes in SIC. Although cloud feedback does not explain the key feedback differences among CM4.0, SPEAR, and SPEAR-SV, it is the primary cause of the models' increase (less negative) in TOA net feedback during the later period of their quadrupling CO2 simulations due to changes in their SST warming patterns. Moreover, CM4.0's SST warming pattern and its effects on cloud feedback appear to be the leading cause of CM4.0's EffCS increase compared to the earlier generation GFDL model ESM2M, which produces one of the lowest EffCS values among CMIP5 models. In comparison, CM4.0's enhanced reduction in SH SICs plays a slightly less important role in its increase in EffCS compared to ESM2M. [ABSTRACT FROM AUTHOR]

Marine ranching has been proposed as a promising solution to manage the depleted coastal fishery ecosystem in recent decades across China. Marine ranching integrates the practices of artificial habitat-based with aquaculture-based enhancement. Assessing the ecological carrying capacity of target species for enhancement is a precondition for determining the optimal numbers for release, particularly for those species whose habitat restrictions have been eliminated through the construction of artificial habitats in the marine ranch. A responsible approach to stock enhancement aims not only to increase total yield and stock abundance but also to consider any potential effects on ecosystem structure and function. A time-dynamic, ecosystem model was constructed using Ecopath with Ecosim for the Laizhou Bay (Bohai Sea) marine ranching ecosystem in the nearshore waters of northern China. Two sedentary target species with potential for stock enhancement, i.e., the carnivorous red snail Rapana venosa and the detritivorous sea cucumber Apostichopus japonicus, were selected to simulate and estimate their ecological carrying capacities and project their overall effects on the ecosystem. Ecological carrying capacity was defined as the maximum standing stocks of the target species that would not cause “unacceptable” impacts on the ecosystem function and resilience, i.e., not cause any other group’s biomass to fall below 10% of its original biomass. The ecological carrying capacities estimated for R. venosa and A. japonicus were 623.46 and 200.57 t·km−2, respectively, corresponding to 7.8 and 5.0 times higher than their current standing stocks. Simulations of R. venosa enhancement showed distinct effects of increased target species abundance on other functional groups and ecosystem properties. An increase in red snail biomass caused negative impacts on the biomass of most other functional groups and ecosystem indicators, such as Finn’s cycling index, transfer efficiency, and Kempton’s Q index. In contrast, the simulated A. japonicus enhancement had relatively few impacts, and the biomasses of most other functional groups and ecosystem indicators did not change or changed very slightly (

It is increasingly evident that climate sustainability depends not only on societal actions and responses, but also on ecosystem functioning and responses. The capacity of global ecosystems to provide services such as sequestering carbon and regulating hydrology is being strongly reduced both by climate change itself and by unprecedented rates of ecosystem degradation. These services rely on functional aspects of ecosystems that are causally linked—the same ecosystem components that efficiently sequester and store carbon also regulate hydrology by sequestering and storing water. This means that climate change adaptation and mitigation must involve not only preparing for a future with temperature and precipitation anomalies, but also actively minimizing climate hazards and risks by conserving and managing ecosystems and their fundamental supporting and regulating ecosystem services. We summarize general climate–nature feedback processes relating to carbon and water cycling on a broad global scale before focusing on Norway to exemplify the crucial role of ecosystem regulatory services for both carbon sequestration and hydrological processes and the common neglect of this ecosystem–climate link in policy and landscape management. We argue that a key instrument for both climate change mitigation and adaptation policy is to take advantage of the climate buffering and regulative abilities of a well-functioning natural ecosystem. This will enable shared benefits to nature, climate, and human well-being. To meet the global climate and nature crises, we must capitalize on the importance of nature for buffering climate change effects, combat short-term perspectives and the discounting of future costs, and maintain or even strengthen whole-ecosystem functioning at the landscape level. Significance Statement: Natural ecosystems such as forests, wetlands, and heaths are key for the cycling and storage of water and carbon. Preserving these systems is essential for climate mitigation and adaptation and will also secure biodiversity and associated ecosystem services. Systematic failure to recognize the links between nature and human well-being underlies the current trend of accelerating loss of nature and thereby nature's ability to buffer climate changes and their impacts. Society needs a new perspective on spatial planning that values nature as a sink and store of carbon and a regulator of hydrological processes, as well as for its biodiversity. We need policies that fully encompass the role of nature in preventing climate-induced disasters, along with many other benefits for human well-being. [ABSTRACT FROM AUTHOR]

This article presents an agroecosystem resilience index (ARI) relative to two types of exogenous drivers: biophysical and socioeconomic threats. The ARI is based on a theoretical framework of socioecological systems and draws upon multicriteria analysis. The multicriteria consist of variables related to natural, productive, socioeconomic, and institutional systems that are weighted and grouped through expert judgment. The index was operationalized in the Rio Grande basin (RGB), in the Colombian Andes. The ARI was evaluated at the household level using information from 99 RGB households obtained through workshops, individual semistructured interviews, and surveys. The ARI is a continuous variable that ranges between 0 and 1 and results in five categories of resilience: very low, low, medium, high, and very high. When faced with climate change impacts, 19% of households showed low resilience, 64% showed medium resilience, and 16% showed high resilience according to the ARI. When faced with price fluctuations, 23% of households showed low resilience, 65% showed medium resilience, and 11% showed high resilience. Key variables associated with high resilience include the diversity of vegetation cover, households that have forests on their properties, a high degree of connectivity with other patches of forest, diversification of household economic activities, profitability of economic activities, availability of water sources, and good relationships with local institutions. [ABSTRACT FROM AUTHOR]

Business model management is possible on the basis of detailing and clarifying methods for calculating forms of increasing returns. High-tech companies, in contrast to traditional ones, have additional rents associated with the dual use of technologies and digitalization. The article develops a set of methods for assessing the cumulative increasing returns of a hightech business model based on the calculation of classic and ecosystem effects. The neoclassical economic theory, the network (relational) approach, the concepts of business models and ecosystems constitute the methodological basis of the study. The authors differentiate between five forms of returns: economies of scale effects, effects of innovation, diversity, direct and indirect network-based (ecosystem) effects. The research method is pioneered by the authors and based on a sequential assessment of the five forms of returns. For each form, an optimal calculation method is proposed, the results of which are unified by the standardization method. The level of increasing returns is empirically calculated using the case study of the civil production of the Semikhatov Scientific and Production Association (SPA) of Automatics – one of the largest high-tech industrial enterprises. The paper highlights the problems in measuring returns, such as the lack of panel data on the enterprise, a uniform method and relevant examples for calculation, as well as objective data on sectoral markets. The research results prove that the key management objective is to enhance the positive difference between increasing and decreasing returns through transformation of the business model. To achieve this objective, we compile a matrix of effects, the level of which allows making appropriate management decisions. Our calculations show that the enterprise experiences decreasing returns from adoption of innovation. The level of increasing returns from the learning effect and the direct network-based effect is quite low, which indicates that the enterprise’s business model is traditional, rather than technological. The research results can serve as a basis for the development of a detailed management mechanism for transforming a business model. The method for increasing returns assessment is universal and can be applied to evaluate the effectiveness of any business models.

Changing pathways of soil moisture loss, either directly from soil (evaporation) or indirectly through vegetation (transpiration), are an indicator of ecosystem and land hydrological cycle responses to the changing climate. Based on the ratio of transpiration to evaporation, this paper investigates soil moisture loss pathway changes across China using five reanalysis-type datasets for the past and Coupled Model Intercomparison Project Phase 6 (CMIP6) climate projections for the future. The results show that across China, the ratio of vegetation transpiration to soil evaporation has generally increased across vegetated land areas, except in grasslands and croplands in north China. During 1981–2014, there was an increase by 51.4 percentage points (pps, p < 0.01) on average according to the reanalyses and by 42.7 pps according to 13 CMIP6 models. The CMIP6 projections suggest that the holistic increasing trend will continue into the twenty-first century at a rate of 40.8 pps for SSP585, 30.6 pps for SSP245, and −1.0 pps for SSP126 shared socioeconomic pathway scenarios for the period 2015–2100 relative to 1981–2014. Major contributions come from the increases in vegetation transpiration over the semiarid and subhumid grasslands, croplands, and forestlands under the influence of increasing temperatures and prolonged growing seasons (with twin peaks in May and October). The future increasing vegetation transpiration ratio in soil moisture loss implies the potential of regional greening across China under global warming and the risks of intensifying land surface dryness and altering the coupling between soil moisture and climate in regions with water-limited ecosystems. [ABSTRACT FROM AUTHOR]

Modular Observation Solutions of Earth Systems (MOSES) is a novel observation system that is specifically designed to unravel the impact of distinct, dynamic events on the long-term development of environmental systems. Hydrometeorological extremes such as the recent European droughts or the floods of 2013 caused severe and lasting environmental damage. Modeling studies suggest that abrupt permafrost thaw events accelerate Arctic greenhouse gas emissions. Short-lived ocean eddies seem to comprise a significant share of the marine carbon uptake or release. Although there is increasing evidence that such dynamic events bear the potential for major environmental impacts, our knowledge on the processes they trigger is still very limited. MOSES aims at capturing such events, from their formation to their end, with high spatial and temporal resolution. As such, the observation system extends and complements existing national and international observation networks, which are mostly designed for long-term monitoring. Several German Helmholtz Association centers have developed this research facility as a mobile and modular "system of systems" to record energy, water, greenhouse gas, and nutrient cycles on the land surface, in coastal regions, in the ocean, in polar regions, and in the atmosphere—but especially the interactions between the Earth compartments. During the implementation period (2017–21), the measuring systems were put into operation and test campaigns were performed to establish event-driven campaign routines. With MOSES's regular operation starting in 2022, the observation system will then be ready for cross-compartment and cross-discipline research on the environmental impacts of dynamic events. [ABSTRACT FROM AUTHOR]

Global climate change is a key driver of change in coastal waters with clear effects on biological communities and marine ecosystems. Human activities in combination with climate change exert a tremendous pressure on marine ecosystems and threaten their integrity, structure, and functioning. The protection of these ecosystems is a major target of the 14th United Nations sustainable development goal “Conserve and sustainably use the oceans, seas and marine resources for sustainable development.” However, due to the complexity of processes and interactions of stressors, the status assessment of ecosystems remains a challenge. Holistic food web models, including biological and environmental data, could provide a suitable basis to assess ecosystem health. Here, we review climate change impacts on different trophic levels of coastal ecosystems ranging from plankton to ecologically and economically important fish and shellfish species. Furthermore, we show different food web model approaches, their advantages and limitations. To effectively manage coastal ecosystems, we need both a detailed knowledge base of each trophic level and a holistic modeling approach for assessment and prediction of future scenarios on food web-scales. A new model approach with a seamless coupling of physical ocean models and food web models could provide a future tool for guiding ecosystem-based management.

Drought is a complex challenge experienced in specific locations through diverse impacts, including ecological impacts. Different professionals involved in drought preparedness and response approach the problem from different points of view, which means they may or may not recognize ecological impacts. This study examines the extent to which interviewees perceive ecological drought in the Upper Missouri Headwaters basin in southwestern Montana. Through semistructured interviews, this research investigates individuals' perceptions of drought by analyzing how they define drought, how they describe their roles related to drought, and the extent to which they emphasize ecological impacts of drought. Results suggest that while most interviewees have an integrated understanding of drought, they tend to emphasize either ecological or nonecological impacts of drought. This focus was termed their drought orientation. Next, the analysis considers how participants understand exposure to drought. Results indicate that participants view drought as a complex problem driven by both human and natural factors. Last, the paper explores understandings of the available solution space by examining interviewees' views on adaptive capacity, particularly factors that facilitate or hinder the ability of the UpperMissouri Headwaters region to cope with drought. Participants emphasized that adaptive capacity is both helped and hindered by institutional, cultural, and economic factors, as well as by available information and past resource management practices. Understanding how interviewees perceive the challenges of drought can shape drought preparedness and response, allowing those designing programs to better align their efforts to the perceptions of their target audience. [ABSTRACT FROM AUTHOR]

Lakes are vulnerable to climate change, and warming rates in the Arctic are faster than anywhere on Earth. Fishes are sensitive to changing temperatures, which directly control physiological processes. Food availability should partly dictate responses to climate change because energetic demands change with temperature, but few studies have simultaneously examined temperature and food availability.We used a fully factorial experiment to test effects of food availability and temperature (7.6, 12.7, and 17.4°C; 50 days) on growth, consumption, respiration, and excretion, and effects of temperature (12 and 19.3°C; 27 days) on habitat use and growth of a common, but understudied, mid‐level consumer, slimy sculpin Cottus cognatus, in arctic lakes. We also used bioenergetics modelling to predict consumptive demand under future warming scenarios.Growth rates were 3.4× higher at 12.7°C in high food compared to low food treatments, but the magnitude of differences depended on temperature. Within low food treatments, there was no statistical difference in growth rates among temperatures, suggesting food limitation. Consumption, respiration, and nitrogen excretion increased with temperature independent of food availability. Lower growth rates coincided with lower phosphorus excretion at the highest temperature, suggesting that fish selectively retained phosphorus at high temperatures and low food. In habitat choice experiments, fish were more likely to use the 12°C side of the tank, closely matching their optimal temperature. We predicted a 9% increase in consumption is required to maintain observed growth under a 4°C warming scenario.These results highlight considering changes in food resources and other associated indirect effects (e.g. excretion) that accompany changing temperatures with climate change. Depending on how food webs respond to warming, fish may cope with predicted warming if density‐dependent feedback maintains population sizes. [ABSTRACT FROM AUTHOR]

Ocean acidification is one of the most dramatic effects of the massive atmospheric release of anthropogenic carbon dioxide (CO2) that has occurred since the Industrial Revolution, although its effects on marine ecosystems are not well understood. Submarine volcanic hydrothermal fields have geochemical conditions that provide opportunities to characterise the effects of elevated levels of seawater CO2 on marine life in the field. Here, we review the geochemical aspects of shallow marine CO2-rich seeps worldwide, focusing on both gas composition and water chemistry. We then describe the geochemical effects of volcanic CO2 seepage on the overlying seawater column. We also present new geochemical data and the first synthesis of marine biological community changes from one of the best-studied marine CO2 seep sites in the world (off Vulcano Island, Sicily). In areas of intense bubbling, extremely high levels of pCO2 (> 10,000 μatm) result in low seawater pH (< 6) and undersaturation of aragonite and calcite in an area devoid of calcified organisms such as shelled molluscs and hard corals. Around 100–400 m away from the Vulcano seeps the geochemistry of the seawater becomes analogous to future ocean acidification conditions with dissolved carbon dioxide levels falling from 900 to 420 μatm as seawater pH rises from 7.6 to 8.0. Calcified species such as coralline algae and sea urchins fare increasingly well as sessile communities shift from domination by a few resilient species (such as uncalcified algae and polychaetes) to a diverse and complex community (including abundant calcified algae and sea urchins) as the seawater returns to ambient levels of CO2. Laboratory advances in our understanding of species sensitivity to high CO2 and low pH seawater, reveal how marine organisms react to simulated ocean acidification conditions (e.g., using energetic trade-offs for calcification, reproduction, growth and survival). Research at volcanic marine seeps, such as those off Vulcano, highlight consistent ecosystem responses to rising levels of seawater CO2, with the simplification of food webs, losses in functional diversity and reduced provisioning of goods and services for humans. [ABSTRACT FROM AUTHOR]

There is increasing conflict between snow leopards and humans in many protected areas, the main driver of which is the overlap in spatial utilization between snow leopards and livestock. Understanding the spatial utilization and microhabitat selection of snow leopards in areas featuring different levels of livestock grazing is important to better understand and resolve this conflict, but such studies are rare. Here, we conducted line transect and plot surveys in low- and high-grazing-disturbance areas (LGDAs and HGDAs) in Wolong National Reserve, southwestern China. We compared snow leopard spatial utilization and microhabitat characteristics between LGDAs and HGDAs. Results showed that snow leopards had aggregated distribution in both LGDAs and HGDAs, but the distribution of snow leopards in HGDAs was more centralized than in LGDAs. Herb cover and height in LGDAs were greater than in HGDAs. We fit a resource selection function (RSF) that showed that snow leopards preferentially selected higher elevation, smaller basal diameter of shrubs, and lower height of herbs in LGDAs. In contrast, there were no significant microhabitat factors in our snow leopard RSF in HGDAs. Our results indicate that high-intensity grazing tends to reduce the habitat types available to and preferential selectivity of habitat by snow leopards. We recommend that livestock grazing should be controlled to restore the diversity of the alpine ecosystems in Wolong Nature Reserve. Our findings also highlight the need for evaluating the impact of livestock grazing on rare animals in alpine environments (e.g., snow leopard) in other areas facing similar issues. [ABSTRACT FROM AUTHOR]

Alaska's Yukon–Kuskokwim Delta (YKD) is among the Arctic's warmest, most biologically productive regions, but regional decline of the normalized difference vegetation index (NDVI) has been a striking feature of spaceborne Advanced High Resolution Radiometer (AVHRR) observations since 1982. This contrast with "greening" prevalent elsewhere in the low Arctic raises questions concerning climatic and biophysical drivers of tundra productivity along maritime–continental gradients. We compared NDVI time series from AVHRR, the Moderate Resolution Imaging Spectroradiometer (MODIS), and Landsat for 2000–19 and identified trend drivers with reference to sea ice and climate datasets, ecosystem and disturbance mapping, field measurements of vegetation, and knowledge exchange with YKD elders. All time series showed increasing maximum NDVI; however, whereas MODIS and Landsat trends were very similar, AVHRR-observed trends were weaker and had dissimilar spatial patterns. The AVHRR and MODIS records for time-integrated NDVI were dramatically different; AVHRR indicated weak declines, whereas MODIS indicated strong increases throughout the YKD. Disagreement largely arose from observations during shoulder seasons, when there is partial snow cover and very high cloud frequency. Nonetheless, both records shared strong correlations with spring sea ice extent and summer warmth. Multiple lines of evidence indicate that, despite frequent disturbances and high interannual variability in spring sea ice and summer warmth, tundra productivity is increasing on the YKD. Although climatic drivers of tundra productivity were similar to more continental parts of the Arctic, our intercomparison highlights sources of uncertainty in maritime areas like the YKD that currently, or soon will, challenge historical concepts of "what is Arctic." [ABSTRACT FROM AUTHOR]

Variability in soil moisture has implications for regional terrestrial environments under a warming climate. This paper focuses on the spatiotemporal variability in the intra-annual persistence of soil moisture in China using the fifthgeneration reanalysis dataset by the European Centre for Medium-Range Weather Forecasts for the period 1979-2018. The results show that in China, the mean intra-annual persistence in the humid to arid zones increased from 60 to 115 days in the lower layer but decreased from 19 to 13 days and from 25 to 14 days in the upper and root layers, respectively. However, these changes were strongly attenuated in extremely dry and wet regions due to the scarcity of soil moisture anomalies. Large changes in persistence occurred in the lower soil layer in dryland areas, with a mean difference of up to 40 days between the 2010s and the 1980s. Overall increasing trends dominated the large-scale spatial features, despite regional decreases in the eastern arid zone and the North and Northeast China plains. In the root layer, the two plains experienced an expanded decrease while on the Tibetan Plateau it was dominated by decadal variability. These contrasting changes between the lower and root layers along the periphery of the transition zone was a reflection of the enhanced soil hydrological cycle in the root layer. The enhanced persistence in drylands lower layer is an indication of the intensified impacts of soil moisture anomalies (e.g., droughts) on terrestrial water cycle. These findings may help the understanding of climate change impacts on terrestrial environments. [ABSTRACT FROM AUTHOR]

Aims: Novel ecosystems are self‐maintaining ecosystems that support species assemblages without historical precedent. Despite much interest and controversy around novel ecosystems, it remains poorly understood how they are generated, what their capacity to support biodiversity is and what the implications for society are. Here, we address these issues through a global synthesis of non‐native palms, since palms are likely generators of novel ecosystems because they are introduced widely beyond their native range and have the capacity to act as ecosystem engineers. Location: Global. Methods: We gathered data on non‐native palms from peer‐reviewed literature/papers, grey literature and online databases. We extracted data on the biogeographic context of palm invasions, plant functional traits and anthropogenic drivers to quantify their effects on biodiversity, ecosystem functioning and ecosystem services. Results: Of the 2,557 palm species, 3.4% (86 species) were recorded as naturalized and 1.1% (28 species) as invasive, which exceeds the average invasion success across all woody plants. Naturalized palms are present in most tropical and subtropical regions around the world, often in urban areas, reflecting the use of palms in horticulture. Many naturalized palms were taller and more likely to originate from open habitats or dry forest than non‐naturalized palms. These features likely represent the naturalized palms' competitive ability, high fecundity and dispersal ability along with ecological matching to human‐disturbed environments. Overall, literature on ecological effects of palm invasions was sparse, but we found multiple cases in which palm invasions resulted in strong ecosystem changes or even biome shifts. Main Conclusions: We found strong evidence that palm invasions can generate novel ecosystems. Although there are substantial knowledge gaps on the ecological effects of palm invasion, anthropogenic drivers like urbanization and ongoing global warming will continue to expand palm ranges and promote non‐native palms as generators of novel ecosystems. [ABSTRACT FROM AUTHOR]

Warm-season rainfall associated with mesoscale convective systems (MCSs) in the central United States is characterized by higher intensity and nocturnal timing compared to rainfall from non-MCS systems, suggesting their potentially different footprints on the land surface. To differentiate the impacts of MCS and non-MCS rainfall on the surface water balance, a water tracer tool embedded in the Noah land surface model with multiparameterization options (WT-Noah-MP) is used to numerically ''tag'' water from MCS and non-MCS rainfall separately during April-August (1997-2018) and track their transit in the terrestrial system. From the water-tagging results, over 50% of warm-season rainfall leaves the surface-subsurface system through evapotranspiration by the end of August, but non-MCS rainfall contributes a larger fraction. However, MCS rainfall plays a more important role in generating surface runoff. These differences are mostly attributed to the rainfall intensity differences. The higher-intensity MCS rainfall tends to produce more surface runoff through infiltration excess flow and drives a deeper penetration of the rainwater into the soil. Over 70% of the top 10th percentile runoff is contributed by MCS rainfall, demonstrating its important contribution to local flooding. In contrast, lower-intensity non-MCS rainfall resides mostly in the top layer and contributes more to evapotranspiration through soil evaporation. Diurnal timing of rainfall has negligible effects on the flux partitioning for both MCS and non- MCS rainfall. Differences in soil moisture profiles for MCS and non-MCS rainfall and the resultant evapotranspiration suggest differences in their roles in soil moisture-precipitation feedbacks and ecohydrology. [ABSTRACT FROM AUTHOR]

In recent years, the community structure of fishery resources in offshore waters has undergone significant changes, and the resources of traditional commercial fish have gradually declined; as a result, crustaceans have become the main catch. To prevent the loss of resources, it is necessary to carry out ecological stock enhancement and scientifically prevent and control the ecological risks of released species. In this study, based on the Ecopath with Ecosim model, the areas of marine ranching and adjacent waters in Haizhou Bay were used as a case study to construct a temporal dynamic model of Portunus trituberculatus , one of the typical crustacea released in offshore water of China. The ecological carrying capacity (ECC) of P. trituberculatus was assessed, and its impact on other functional groups and ecosystems was predicted. The results showed that the ECC of P. trituberculatus is 42.458 t km−2, and the entire ecosystem would become imbalanced if this value is exceeded. Under the four simulation scenarios, each ecosystem indicator showed positive responses to different degrees, with total system respiration (R) and total system biomass (B) increasing by 244.66% and 236.90%, respectively. We believe that the maturity of the ecosystem in Haizhou Bay is not high, and the marine organisms are mostly in trophic levels Ⅱ to Ⅲ. Therefore, there is still room for the stock enhancement of P. trituberculatus. The model framework provides a method for assessing the ECC of P. trituberculatus in offshore water and offers a scientific reference and practical basis for stock enhancement activities, resource management, and fishing strategies for P. trituberculatus in the offshore waters of China. • To assess the ecological capacity of Portunus trituberculatus. • To predict the variation of releasing capacity before and after stock enhancement. • To provide scientific recommendations for the stock enhancement sustainability. [ABSTRACT FROM AUTHOR]

Using a bioenergetics model, we estimated daily ration and seasonal prey consumption rates for six age classes of juvenile sandbar sharks (Carcharhinus plumbeus) in the lower Chesapeake Bay summer nursery area. The model, incorporating habitat and species-specific data on growth rates, metabolic rate, diet composition, water temperature (range 16.8-27.9 degrees C), and population structure, predicted mean daily rations between 2.17 +/- 0.03 (age-0) and 1.30 +/- 0.02 (age-5) % body mass/day. These daily rations are higher than earlier predictions for sandbar sharks but are comparable to those for ecologically similar shark species. The total nursery population of sandbar sharks was predicted to consume similar to 124,000 kg of prey during their 4.5 month stay in the Chesapeake Bay nursery. The predicted consumption rates support the conclusion that juvenile sandbar sharks exert a lesser top-down effect on the Chesapeake Bay ecosystem than do teleost piscivores and humans.

Spatial variations in land use/land cover (LULC) in the Midwest U.S. Corn Belt—specifically, deciduous forest and croplands—have been suggested as influencing convective rainfall through mesoscale circulations generated in the atmosphere's boundary layer. However, the contributing role of latent and sensible heat fluxes for these two LULC types, and their modulation by synoptic weather systems, have not been determined. This study compares afternoon averages of convective fluxes at two AmeriFlux towers in relation to manually determined synoptic pressure patterns covering the nine growing seasons (1 May–30 September) of 1999–2007. AmeriFlux tower U.S.-Bo1 in eastern Illinois represents agricultural land use—alternating between maize and soybean crops—and AmeriFlux tower U.S.-MMS in south-central Indiana represents deciduous forest cover. Phenologically, the latent and sensible heat fluxes vary inversely across the growing season, and the greatest flux differences between cropland and deciduous forest occur early in the season. Differences in the surface heat fluxes between crop and forest LULC types vary in magnitude according to synoptic type. Moreover, statistically significant differences in latent and sensible heat between the forest and cropland sites occur for the most frequently occurring synoptic pattern of a low pressure system to the west and high pressure to the east of the Corn Belt. The present study lays the groundwork for determining the physical mechanisms of enhanced convection in the Corn Belt, including how LULC-induced mesoscale circulations might interact with synoptic weather patterns to enhance convective rainfall. [ABSTRACT FROM AUTHOR]

A vast body of research demonstrates that many ecological and evolutionary processes can only be understood from a tri‐trophic viewpoint, that is, one that moves beyond the pairwise interactions of neighbouring trophic levels to consider the emergent features of interactions among multiple trophic levels. Despite its unifying potential, tri‐trophic research has been fragmented, following two distinct paths. One has focused on the population biology and evolutionary ecology of simple food chains of interacting species. The other has focused on bottom‐up and top‐down controls over the distribution of biomass across trophic levels and other ecosystem‐level variables. Here, we propose pathways to bridge these two long‐standing perspectives. We argue that an expanded theory of tri‐trophic interactions (TTIs) can unify our understanding of biological processes across scales and levels of organisation, ranging from species evolution and pairwise interactions to community structure and ecosystem function. To do so requires addressing how community structure and ecosystem function arise as emergent properties of component TTIs, and, in turn, how species traits and TTIs are shaped by the ecosystem processes and the abiotic environment in which they are embedded. We conclude that novel insights will come from applying tri‐trophic theory systematically across all levels of biological organisation. [ABSTRACT FROM AUTHOR]

Harvesting wild seaweeds has a long history and is still relevant today, even though aquaculture now supplies >96% of global seaweed production. Current wild harvests mostly target canopy-forming kelp, rockweed and red macroalgae that provide important ecosystem roles, including primary production, carbon storage, nutrient cycling, habitat provision, biodiversity and fisheries support. Harvest methods range from selective hand-cutting to bottom trawling. Resulting ecosystem impacts depend on extraction method and scale, ranging from changes in primary production to habitat disruption, fragmentation, food-web alterations and bycatch of non-target species. Current management often aims for sustainable harvesting in a single-species context, although some agencies acknowledge the wider ecosystem structure, functions and services seaweeds provide. We outline potential ecosystem-based management approaches that would help sustain productive and diverse seaweed-based ecosystems. These include maintaining high canopy biomass, recovery potential, habitat structure and connectivity, limiting bycatch and discards, while incorporating seasonal closures and harvest-exclusion zones into spatial management plans. Other sustainability considerations concern monitoring, enforcement and certification standards, a shift to aquaculture, and addressing cumulative human impacts, invasive species and climate change. Our review provides a concise overview on how to define and operationalize ecosystem-based management of seaweed harvesting that can inform ongoing management and conservation efforts. [ABSTRACT FROM AUTHOR]

Invasive European Reed (Phragmites australis subsp. australis) outcompetes native vegetation, reducing floristic diversity and habitat value for wildlife. Research in coastal salt marshes has indicated that P. australis invasion may be facilitated by its relatively deep rooting depth, but in freshwater marshes the growth pattern of below ground tissues in relation to water depth is uncertain. To determine if P. australis is rooting more deeply than resident wetland plant species in a freshwater coastal marsh on Lake Erie, Ontario, we measured the vertical distribution of below ground biomass in P. australis invaded marsh sites and compared it to the below ground biomass distribution in nearby sites not yet invaded by P. australis. These invaded and uninvaded sites were paired by water depth, which is known to influence resource allocation and rooting depth. Below ground biomass in invaded sites was greater than in uninvaded sites (t28 = 3.528, P = 0.001), but rooting depth (i.e., the depth at which 90% of total below ground biomass is accounted for) was comparable (t28 = 0.992, P = 0.330). Using water depth and site type, general linear models could predict below ground biomass (F2,55 = 9.115, P < 0.001) but not rooting depth (F2,55 = 1.175, P = 0.316). Rooting depth is likely affected by other factors such as substrate type and the depth of the organic soil horizon. [ABSTRACT FROM AUTHOR]

Clouds can modify terrestrial productivity by reducing total surface radiation and increasing diffuse radiation, which may be more evenly distributed through plant canopies and increase ecosystem carbon uptake (the "diffuse fertilization effect"). Previous work at ecosystem-level observational towers demonstrated that diffuse photosynthetically active radiation (PAR; 400–700 nm) increases with cloud optical thickness (COT) until a COT of approximately 10, defined here as the "low-COT regime." To identify whether the low-COT regime also influences carbon uptake on broader spatial and longer temporal time scales, we use global, monthly data to investigate the influence of COT on carbon uptake in three land-cover types: shrublands, forests, and croplands. While there are limitations in global gross primary production (GPP) products, global COT data derived from Moderate Resolution Imaging Spectroradiometer (MODIS) reveal that during the growing season tropical and subtropical regions more frequently experience a monthly low-COT regime (>20% of the time) than other regions of the globe. Contrary to ecosystem-level studies, comparisons of monthly COT with monthly satellite-derived solar-induced chlorophyll fluorescence and modeled GPP indicate that, although carbon uptake generally increases with COT under the low-COT regime, the correlations between COT and carbon uptake are insignificant (p > 0.05) in shrublands, forests, and croplands at regional scales. When scaled globally, vegetated regions under the low-COT regime account for only 4.9% of global mean annual GPP, suggesting that clouds and their diffuse fertilization effect become less significant drivers of terrestrial carbon uptake at broader spatial and temporal scales. [ABSTRACT FROM AUTHOR]

Trends and transitions in the growing-season normalized difference vegetation index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor at 250-m resolution were analyzed for the period from 2000 to 2018 to understand recent patterns of vegetation change in ecosystems of the Arctic National Wildlife Refuge (ANWR) in Alaska. Statistical analysis of changes in the NDVI time series was conducted using the breaks for additive seasonal and trend method (BFAST). This structural change analysis indicated that NDVI breakpoints and negative 18-yr trends in vegetation greenness over the years since 2000 could be explained in large part by the impacts of severe wildfires. At least one NDVI breakpoint was detected in around 20% of the MODIS pixels within both the Porcupine River and Coleen River basins of the study area. The vast majority of vegetation cover in the ANWR Brooks Range and coastal plain ecoregions was detected with no (positive or negative) growing-season NDVI trends since the year 2000. Results suggested that most negative NDVI anomalies in the 18-yr MODIS record have been associated with early spring thawing and elevated levels of surface moisture in low-elevation drainages of the northern ANWR ecoregions. [ABSTRACT FROM AUTHOR]

Arguments for the need to conserve aquatic predator (AP) populations often focus on the ecological and socioeconomic roles they play. Here, we summarize the diverse ecosystem functions and services connected to APs, including regulating food webs, cycling nutrients, engineering habitats, transmitting diseases/parasites, mediating ecological invasions, affecting climate, supporting fisheries, generating tourism, and providing bioinspiration. In some cases, human-driven declines and increases in AP populations have altered these ecosystem functions and services. We present a social ecological framework for supporting adaptive management decisions involving APs in response to social and environmental change. We also identify outstanding questions to guide future research on the ecological functions and ecosystem services of APs in a changing world. Highlights APs contribute to various ecosystem functions and services. AP population declines and increases can lead to alterations in these processes. Research priorities remain, including effects of climate change. Application of a social ecological framework can support adaptive management of APs. [ABSTRACT FROM AUTHOR]

Vertically integrated atmospheric water vapor (VIWV) over the Indo-Pacific warm pool (IPWP) indirectly affects terrestrial vegetation growth (TVG) patterns through atmospheric water vapor transmission. However, their linkages and mechanisms are poorly understood. This study intends to understand the contributions of VIWVIPWP to TVG and the mechanisms by which VIWVIPWP impacts TVG. Combining monthly SST, VIWV, and NDVI data from 1982 to 2015, the linkage between VIWVIPWP and NDVI is investigated during April–June (AMJ). A strong correlation between VIWVIPWP and NDVI suggests that VIWVIPWP is an important factor affecting TVG. A composite analysis of VIWVIPWP anomalies and their relation to NDVI patterns shows that VIWVIPWP positively influences the NDVI of 68.1% of global green land during high-VIWVIPWP years but negatively influences 74.7% in low years. Corresponding to these results, during high-VIWVIPWP years, the warm and humid terrestrial climate conditions improved TVG by 9% and 2% in the Northern and Southern Hemispheres, respectively, but cold and dry conditions inhibited TVG for both hemispheres during the low years. Additionally, strong spatial correlations between VIWVIPWP and precipitation imply that VIWVIPWP affects the spatial–temporal pattern of precipitation. There is a stronger interaction between the Pacific north–south ridge and the two land troughs during high-VIWVIPWP years than during low-VIWVIPWP years. The zonally averaged wind at 850 hPa and VIWV results indicate that, during high-VIWVIPWP years, the enhanced wind from the ocean brings more atmospheric water vapor to land, increasing the probability of precipitation and resulting in moist climate conditions that promote AMJ vegetation growth. In brief, VIWVIPWP indirectly induces vegetation growth by affecting the distributions of terrestrial VIWV and precipitation. [ABSTRACT FROM AUTHOR]

Drought is widely written about as a complex, multifaceted phenomenon, with complexity arising not just from biophysical drivers, but also human understanding and experiences of drought and its impacts. This has led to a proliferation of different drought definitions and indicators, creating a challenge for the design of drought monitoring and early warning (MEW) systems, which are a key component of drought preparedness. Here, we report on social learning workshops conducted in the United Kingdom aimed at improving the design and operation of drought MEW systems as part of a wider international project including parallel events in the United States and Australia. We highlight key themes for MEW design and use: "types" of droughts, indicators and impacts, uncertainty, capacity and decision-making, communications, and governance. We shed light on the complexity of drought through the multiple framings of the problem by different actors, and how this influences their needs for MEW. Our findings suggest that MEW systems need to embrace this complexity and strive for consistent messaging while also tailoring information for a wide range of audiences in terms of the drought characteristics, temporal and spatial scales, and impacts that are important for their particular decision-making processes. We end with recommendations to facilitate this approach. [ABSTRACT FROM AUTHOR]

The response of the biosphere to variation in climate plays a key role in predicting the carbon cycle, hydrological cycle, terrestrial surface energy balance, and the feedbacks in the climate system. Predicting the response of Earth's biosphere to global warming requires the ability to mechanistically represent the processes controlling photosynthesis, respiration, and water use. This study uses observations of the sensitivity of leaf area to the physical environment to identify where ecosystem functioning is well simulated in an ensemble of Earth system models. These patterns and data–model comparisons are leveraged to hypothesize which physiological mechanisms—photosynthetic efficiency, respiration, water supply, atmospheric water demand, and sunlight availability—dominate the ecosystem response in places with different climates. The models are generally successful in reproducing the broad sign and shape of the sensitivity of leaf area to interannual variations in climate, except for simulating generally decreased leaf area during warmer years in places with hot, wet climates. In addition, simulated sensitivity of the leaf area to temperature is generally larger and changes more rapidly across a gradient of temperature than is observed. We hypothesize that the amplified sensitivity and change are both due to a lack of adaptation and acclimation in simulations. This discrepancy with observations suggests that the simulated sensitivities of vegetation climate are too strong in the models. Finally, models and observations share an abrupt threshold between dry regions and wet regions around 1000 mm yr−1. [ABSTRACT FROM AUTHOR]

Ecosystem-based Adaptation (EbA) is increasingly being advocated as a climate adaptation approach that can deliver multiple benefits to communities. EbA scholarship argues that community-based projects can strengthen those ecosystems that deliver critical services to communities and in doing so enhance community resilience. In particular, the inclusion of indigenous and traditional knowledge (ITK) into community-based EbA projects is positioned as critical to successful climate adaptation. Yet, there is surprisingly little investigation into how ITK is being defined and incorporated into EbA initiatives. This paper critically reviews EbA literature and provides empirical examples from Vanuatu and Samoa to demonstrate the different ways ITK relates to EbA projects. We find that there is widespread recognition that ITK is important for indigenous and local communities and can be employed successfully in EbA. However, this recognition is more aspirational than practical and is not being necessarily translated into ITK-informed or ITK-driven EbA projects. ITK should not be conceptualized simply as a collection of local environmental information that is integrated with Western scientific knowledge. Instead, ITK is part of nested knowledge systems (information–practices–worldviews) of indigenous peoples. This knowledge includes local natural resource management, sociocultural governance structures, social norms, spiritual beliefs, and historical and contemporary experiences of colonial dispossession and marginalization. At present, most EbA projects focus on the provision of information to main decision-makers only; however, since ITK is held collectively, it is essential that entire communities are included in ITK EbA projects. There is a huge potential for researchers and ITK holders to coproduce knowledge that would be best placed to drive climate adaptation in a changing world. [ABSTRACT FROM AUTHOR]

Cold stress is a major environmental constraint that limits nut productivity worldwide. Late spring frost is identified as a yield-reducing factor in Persian walnut production as well. Despite significant improvements in cold and freezing tolerance methods, orchardists have not taken advantage of these recommended protection methods. This study examined determinants of walnut orchardists' frost-protection behavior, using the extended theory of planned behavior (TPB) as a conceptual framework. Based on TPB assumptions, frost-protection behavior is mediated by a series of constructs. The purpose of this research was to examine the role of TPB variables (extended by orchard-system profile) in meeting the necessities of performing active and passive methods of frost protection. A total of 91 orchardists completed a baseline questionnaire that included the TPB constructs. The present investigation was carried out in the major walnut growing site of Sepidan County, western Fars Province, Iran. The results from the hierarchical multiple regression showed that the behavioral attitude, perceived behavioral control (PBC), intention, orchard-system profile, and interaction of orchard-system features and PBC were significant predictors of frost-protection behavior in the prospective sample. Results of the present study provided evidence that the extended TPB is a useful framework for understanding orchardists' frost-protection behavior. [ABSTRACT FROM AUTHOR]

Earth system models (ESMs) simulate a large spread in carbon cycle feedbacks to climate change, particularly in their prediction of cumulative changes in terrestrial carbon storage. Evaluating the performance of ESMs against observations and assessing the likelihood of long-term climate predictions are crucial for model development. Here, we assessed the use of atmospheric CO2 growth rate variations to evaluate the sensitivity of tropical ecosystem carbon fluxes to interannual temperature variations. We found that the temperature sensitivity of the observed CO2 growth rate depended on the time scales over which atmospheric CO2 observations were averaged. The temperature sensitivity of the CO2 growth rate during Northern Hemisphere winter is most directly related to the tropical carbon flux sensitivity since winter variations in Northern Hemisphere carbon fluxes are relatively small. This metric can be used to test the fidelity of interactions between the physical climate system and terrestrial ecosystems within ESMs, which is especially important since the short-term relationship between ecosystem fluxes and temperature stress may be related to the long-term feedbacks between ecosystems and climate. If the interannual temperature sensitivity is used to constrain long-term temperature responses, the inferred sensitivity may be biased by 20%, unless the seasonality of the relationship between the observed CO2 growth rate and tropical fluxes is taken into account. These results suggest that atmospheric data can be used directly to evaluate regional land fluxes from ESMs, but underscore that the interaction between the time scales for land surface processes and those for atmospheric processes must be considered. [ABSTRACT FROM AUTHOR]