Changes In Ecosystem Function Research Articles

Contrasting carbon cycle responses to dry (2015 El Niño) and wet (2008 La Niña) extreme events at an Amazon tropical forest

Land surface models diverge in their predictions of the Amazon forest's response to climate change-induced droughts, with some showing a catastrophic collapse of forests, while others simulating resilience. Therefore, observations of tropical ecosystem responses to real-world droughts and other extreme events are needed. We report long-term seasonal dynamics of photosynthesis, respiration, net carbon exchange, phenology, and tree demography and characterize the effect of dry and wet events on ecosystem form and function at the Tapajós National Forest, Brazil, using over two decades of eddy covariance observations that include the 2015–2016 El Niño drought and La Niña 2008–2009 wet periods. We found strong forest responses to both ENSO events: La Niña saw forest net carbon loss from reduced photosynthesis (due to lower incoming radiation from increased cloudiness) even as ecosystem respiration (Reco) was maintained at mean seasonal levels. El Niño induced the opposite short-term effect, net carbon gains, despite significant reductions in photosynthesis (from a drought-induced halving of canopy conductance to CO2 and significant losses of leaf area), because drought suppression of Reco losses was even greater. However, long-term responses to the two climate perturbations were very different: transient during La Niña –the forest returned to its “normal” state as soon as the climate did, and long-lasting during El Niño –leaf area loss and associated declines in photosynthetic capacity (Pc) and canopy conductance were exacerbated and extended by feedbacks from higher temperatures and atmospheric evaporative demand and persisted for ∼3+ years after normal rainfall resumed. These findings indicate that these forests are more vulnerable to drought than to excess rain, because drought drives significant changes in forest structure (e.g., leaf-abscission and mortality) and ecosystem function (e.g. reduced stomatal conductance). As future Amazonian climate change increases frequencies of hydrological extremes, these mechanisms will determine the long-term fate of tropical forests.

Rethinking ecological niches and geographic distributions in face of pervasive human influence in the Anthropocene.

Species are distributed in predictable ways in geographic spaces. The three principal factors that determine geographic distributions of species are biotic interactions (B), abiotic conditions (A), and dispersal ability or mobility (M). A species is expected to be present in areas that are accessible to it and that contain suitable sets of abiotic and biotic conditions for it to persist. A species' probability of presence can be quantified as a combination of responses to B, A, and M via ecological niche modeling (ENM; also frequently referred to as species distribution modeling or SDM). This analytical approach has been used broadly in ecology and biogeography, as well as in conservation planning and decision-making, but commonly in the context of 'natural' settings. However, it is increasingly recognized that human impacts, including changes in climate, land cover, and ecosystem function, greatly influence species' geographic ranges. In this light, historical distinctions between natural and anthropogenic factors have become blurred, and a coupled human-natural landscape is recognized as the new norm. Therefore, B, A, and M (BAM) factors need to be reconsidered to understand and quantify species' distributions in a world with a pervasive signature of human impacts. Here, we present a framework, termed human-influenced BAM (Hi-BAM, for distributional ecology that (i) conceptualizes human impacts in the form of six drivers, and (ii) synthesizes previous studies to show how each driver modifies the natural BAM and species' distributions. Given the importance and prevalence of human impacts on species distributions globally, we also discuss implications of this framework for ENM/SDM methods, and explore strategies by which to incorporate increasing human impacts in the methodology. Human impacts are redefining biogeographic patterns; as such, future studies should incorporate signals of human impacts integrally in modeling and forecasting species' distributions.

Forest habitat loss and human land use alter predation of artificial ground nests

Anthropogenic disturbances including forestry, urbanisation and agricultural expansion are causing significant habitat loss and fragmentation in boreal forests, leading to changes in ecosystem function. Here, we ask whether these anthropogenic disturbances alter predator–prey spatial overlap in the boreal forest landscape, leading to increased nest predation rates on ground-nesting birds such as forest grouse. To study the roles of forest loss and fragmentation on nest survival, we conducted an artificial nest predation experiment in Finland using 370 camera traps across landscapes varying in forest quantity and fragmentation (measured by edge habitat length). Our artificial nests mimicked the early egg-laying stage of forest grouse. Our primary hypotheses were that nest survival is higher in landscapes with more continuous forest habitat and less edge habitat, and that predator communities differ based on the matrix habitat between the forests. Our findings revealed a negative association with forest cover and nest predation risk, but forest fragmentation, measured as edge length, had no detectable relationship with the nest predation risk. Additionally, nest predation risk depended on the matrix habitat types, with agricultural land and urban areas exhibiting higher predation rates than clearcuts exhibited. Furthermore, the number of predator species observed was positively associated with the level of urban area present. We found that the raccoon dog (Nyctereutes procyonoides), a rather novel invasive alien species, was the most common mammalian nest predator, indicating a change in the predator community. Our results highlight the possible impact of both forest loss and the presence of agricultural and urban areas in the landscape on avian nest survival in forest habitats. We conclude that forest loss may be a more important factor affecting nest predation risk than forest fragmentation.

Natural regeneration of drylands and associated pathways to human health outcomes: Perspectives from rural households

Land degradation and climate change are intertwined global challenges, their implications on human health are driven by the unsustainable use of natural resources, resulting in the loss of vital ecosystem services that support human health. There are equity implications in that landscape degradation disproportionately affects vulnerable populations that live in the most fragile ecosystems. Solutions to reverse degradation are increasingly considered attractive because of their ability to meet multiple societal objectives, however, their implementation has outpaced research on impact; the research and evidence gaps are particularly acute in relation to quantifying the health and well-being impacts of nature-based solutions. This study documents the experiences of rural communities implementing Farmer Managed Natural Regeneration (FMNR) in Central Tanzanian drylands, which integrates trees in agricultural landscapes. FMNR technique has been hailed as the largest positive environmental transformation in African drylands due to its effectiveness in restoring landscapes at very low costs. Despite its success, the impact on human well-being is largely unquantified. We used in-depth group discussions across four villages to document how respondents perceive the health and well-being impacts of natural regeneration. We thereafter adapted the ecosystem services cascade model to conceptualise the pathways between natural regeneration and impact on health and well-being. Respondents across all study sites unanimously reported how FMNR implementation has reversed decades of land degradation, resulting in physical and mental health benefits that can be linked to food and nutritional security, improved air and water quality, income diversification, heat adaptation and gender equality. We demonstrate how the application of the cascade model can generate causal pathways that 1) map how changes in ecosystem structure, functions and services can result in measurable health outcomes, and, 2) support empirical investigation by defining concrete metrics for monitoring and evaluation of interventions.

Precipitation seasonality and soil texture interact to shape dryland recovery from severe disturbance

Abstract Disturbances drive large changes in plant composition and ecosystem functioning in drylands, but current understanding of how recovery following disturbance depends on the environment is limited due to challenges in analysing effects of disparate disturbances across abiotic gradients. We combined remote sensing and field observations across 5600+ km of natural gas pipeline corridors and adjacent undisturbed vegetation to investigate how recovery from a uniform, severe disturbance varied with factors that influence water availability in drylands. We found that recovery of net primary production (NPP) often remains incomplete, with only 42% of our sites projected to fully recover within 100 years. NPP recovery was quicker and more complete in regions that receive most of their annual precipitation at low temperatures and have fine‐textured soil; recovery of total shrub cover (median timing of 81 years) was faster on fine‐textured soils in locations that receive most of their annual precipitation at high temperatures. Locations with quick recovery of shrub cover were linked with a shift in dominant shrub species and incomplete NPP recovery. Synthesis. Recovery of NPP and shrub cover in drylands were driven by different environmental factors. For both NPP and shrub cover, locations with high pre‐disturbance values required more time to recover to adjacent undisturbed levels than locations with low pre‐disturbance values. Quick recovery of shrub cover or productivity was generally linked with a shift in dominant plant species or functional group.

Widespread habitat loss leads to ecosystem-scale decrease in trophic function.

Natural and anthropogenic disturbances have led to rapid declines in the amount and quality of available habitat in many ecosystems. Many studies have focused on how habitat loss has affected the composition and configuration of habitats, but there have been fewer studies that investigate how this loss affects ecosystem function. We investigated how a large-scale seagrass die-off altered the distribution of energetic resources of three seagrass-associated consumers with varied resource use patterns. Using long-term benthic habitat monitoring data and resource use data from Bayesian stable isotope mixing models, we generated energetic resource landscapes (E-scapes) annually between 2007 and 2019. E-scapes link the resources being used by a consumer to the habitats that produce those resources to calculate a habitat resource index as a measurement of energetic quality of the landscape. Overall, our results revealed that following the die-off there was a reduction in trophic function across all species in areas affected by the die-off event, but the response was species-specific and dependent on resource use and recovery patterns. This study highlights how habitat loss can lead to changes in ecosystem function. Incorporating changes in ecosystem function into models of habitat loss could improve understanding of how species will respond to future change.

Tracking effects of extreme drought on coniferous forests from space using dynamic habitat indices

Terrestrial ecosystems such as coniferous forests in Central Europe are experiencing changes in health status following extreme droughts compounding with severe heat waves. The increasing temporal resolution and spatial coverage of earth observation data offer new opportunities to assess these dynamics. Dense time-series of optical satellite data allow for computing Dynamic Habitat Indices (DHIs), which have been predominantly used in biodiversity studies. However, DHIs cover three aspects of vegetation changes that could be affected by drought: annual productivity, minimum cover, and seasonality. Here, we evaluate the health status of coniferous forests in the federal state of Hesse in Germany over the period 2017–2020 including the severe drought year of 2018 using DHIs based on the Normalized Difference Vegetation Index (NDVI) for drought assessment. To identify the most important variables affecting coniferous forest die-off, a series of environmental variables together with the three DHIs components were used in a logistic regression (LR) model. Each DHI component changed significantly across non-damaged and damaged sites in all years (p-value 0.05). When comparing 2017 to 2019, DHI-based annual productivity decreased and seasonality increased. Most importantly, none of the DHI components had reached pre-drought conditions, which likely indicates a change in ecosystem functioning. We also identified spatially explicit areas highly affected by drought. The LR model revealed that in addition to common environmental parameters related to temperature, precipitation, and elevation, DHI components were the most important factors explaining the health status. Our analysis demonstrates the potential of DHIs to capture the effect of drought events on Central European coniferous forest ecosystems. Since the spaceborne data are available at the global level, this approach can be applied to track the dynamics of ecosystem conditions in other regions, at larger spatial scales, and for other Land Use/Land Cover types.

Logging response alters trajectories of reorganization after loss of a foundation tree species.

Forest insect outbreaks cause large changes in ecosystem structure, composition, and function. Humans often respond to insect outbreaks by conducting salvage logging, which can amplify the immediate effects, but it is unclear whether logging will result in lasting differences in forest structure and dynamics when compared with forests affected only by insect outbreaks. We used 15 years of data from an experimental removal of Tsuga canadensis (L.) Carr. (Eastern hemlock), a foundation tree species within eastern North American forests, and contrasted the rate, magnitude, and persistence of response trajectories between girdling (emulating mortality from insect outbreak) and timber harvest treatments. Girdling and logging were equally likely to lead to large changes in forest structure and dynamics, but logging resulted in faster rates of change. Understory light increases and community composition changes were larger and more rapid in the logged plots. Tree seedling and understory vegetation abundance increased more in the girdled plots; this likely occurred because seedlings grew rapidly into the sapling- and tree-size classes after logging and quickly shaded out plants on the forest floor. Downed deadwood pools increased more after logging but standing deadwood pools increased dramatically after girdling. Understory light levels remained elevated for a longer time after girdling. Perhaps because the window of opportunity for understory species to establish was longer in the girdled plots, total species richness increased more in the girdled than logged plots. Despite the potential for greater diversity in the girdled plots, Betula lenta L. (black birch) was the most abundant tree species recruited into the sapling- and tree-size classes in both the girdled and logged plots and is poised to dominate the new forest canopy. The largest difference between the girdling and logging treatments-deadwood structure and quantity-will persist and continue to bolster aboveground carbon storage and structural and habitat diversity in the girdled plots. Human responses to insect outbreaks hasten forest reorganization and remove structural resources that may further alter forest response to ongoing climate stress and future disturbances.

Automated detection of an insect‐induced keystone vegetation phenotype using airborne LiDAR

Abstract Ecologists, foresters and conservation practitioners need ‘biodiversity scanners’ to effectively inventory biodiversity, audit conservation progress and track changes in ecosystem function. Quantifying biological diversity using remote sensing methods remains challenging, especially for small invertebrates. However, insect aggregations can drastically alter landscapes and vegetation, and these ‘extended phenotypes’ could serve as environmental landmarks of insect presence in remotely sensed data. To test the feasibility of this approach, we studied symbiotic ants that alter the canopy shape of whistling thorn acacias (Acacia [syn. Vachellia] drepanolobium), a keystone tree species of the black cotton soils of east African savannas. We demonstrate a protocol for using light detection and ranging (LiDAR) data to collect, prepare (including a customizable tree‐segmentation algorithm) and apply a convolutional neural network‐based classification for the detection of ant‐inhabited acacia tree phenotypic variations. Applying this protocol enabled us to effectively detect intra‐specific tree phenotypic variation induced by insects. Surveying ant occupancy across 16 ha and 9680 acacia trees took 1000 work hours, whereas surveyed patterns of ant distribution were replicated by our trained classifier using only an hour‐long airborne LiDAR collection time. We suggest that large‐scale surveys of insect occupancy (including insect‐vectored disease) can be automated through a combination of airborne LiDAR and machine learning.

Experimental warming promotes phytoplankton species sorting towards cyanobacterial blooms and leads to potential changes in ecosystem functioning

A positive feedback loop where climate warming enhances eutrophication and its manifestations (e.g., cyanobacterial blooms) has been recently highlighted, but its consequences for biodiversity and ecosystem functioning are not fully understood. We conducted a highly replicated indoor experiment with a species-rich subtropical freshwater phytoplankton community. The experiment tested the effects of three constant temperature scenarios (17, 20, and 23 °C) under high-nutrient supply conditions on community composition and proxies of ecosystem functioning, namely resource use efficiency (RUE) and CO2 fluxes. After 32 days, warming reduced species richness and promoted different community trajectories leading to a dominance by green algae in the intermediate temperature and by cyanobacteria in the highest temperature treatments. Warming promoted primary production, with a 10-fold increase in the mean biomass of green algae and cyanobacteria. The maximum RUE occurred under the warmest treatment. All treatments showed net CO2 influx, but the magnitude of influx decreased with warming. We experimentally demonstrated direct effects of warming on phytoplankton species sorting, with negative effects on diversity and direct positive effects on cyanobacteria, which could lead to potential changes in ecosystem functioning. Our results suggest potential positive feedback between the phytoplankton blooms and warming, via lower net CO2 sequestration in cyanobacteria-dominated, warmer systems, and add empirical evidence to the need for decreasing the likelihood of cyanobacterial dominance.

PANABIO: a point-referenced PAN-Arctic data collection of benthic BIOtas

Abstract. Profound environmental changes, such as drastic sea-ice decline, leave large-scale ecological footprints on the distribution and composition of marine biota in the Arctic. Currently, the impact of such stressors is not sufficiently understood due to the lack of pan-Arctic data that allow for estimating ecological baselines as well as modelling current and forecast potential changes in benthic biodiversity and ecosystem functioning. Here, we introduce the PAN-Arctic data collection of benthic BIOtas (PANABIO) and discuss its timeliness, potential, and details of its further development. The data collection contains individual datasets with records (presence, counts, abundance, or biomass) of benthic fauna, usually at genus level or species level, which were identified in field samples obtained at point-referenced locations (stations) by means of grabs, towed gear, or seabed imaging. The data cover the entire pan-Arctic realm, i.e. the central Arctic Ocean, Chukchi Sea, East Siberian Sea, Laptev Sea, Kara Sea, Barents Sea (including the White Sea), Svalbard waters, Greenland Sea, Norwegian Sea, Canadian Archipelago, Beaufort Sea, and Bering Sea as well as some adjacent sub-Arctic regions (Sea of Japan, Gulf of Okhotsk). Currently (as of 14 December 2023), PANABIO includes 27 datasets with a total of 126 388 records of 2978 taxa collected from 11 555 samples taken at 10 596 stations during 1095 cruises between 1800 and 2014. These numbers will increase with more data becoming available over time through contributions from PANABIO users. The data collection is available in a PostgreSQL-based data warehouse that can be accessed and queried through an open-access front-end web service at https://critterbase.awi.de/panabio (last access: 27 February 2024). A snapshot of the current data collection and its 27 individual datasets is also available from the data publisher PANGAEA (https://doi.org/10.1594/PANGAEA.963640, Piepenburg et al., 2023).

Wetness severity increases abrupt shifts in ecosystem functioning in arid savannas.

The accelerating pace of climate change has led to unprecedented shifts in surface temperature and precipitation patterns worldwide, with African savannas being among the most vulnerable regions. Understanding the impacts of these extreme changes on ecosystem health, functioning and stability is crucial. This paper focuses on the detection of breakpoints, indicative of shifts in ecosystem functioning, while also determining relevant ecosystem characteristics and climatic drivers that increase susceptibility to these shifts within the semi-arid to arid savanna biome. Utilising a remote sensing change detection approach and rain use efficiency (RaUE) as a proxy for ecosystem functioning, spatial and temporal patterns of breakpoints in the savanna biome were identified. We then employed a novel combination of survival analysis and remote sensing time series analysis to compare ecosystem characteristics and climatic drivers in areas experiencing breakpoints versus areas with stable ecosystem functioning. Key ecosystem factors increasing savanna breakpoint susceptibility were identified, namely higher soil sand content, flatter terrain and a cooler long-term mean temperature during the wet summer season. Moreover, the primary driver of changes in ecosystem functioning in arid savannas, as opposed to wetter tropical savannas, was found to be the increased frequency and severity of rainfall events, rather than drought pressures. This research highlights the importance of incorporating wetness severity metrics alongside drought metrics to comprehensively understand climate-ecosystem interactions leading to abrupt shifts in ecosystem functioning in arid biomes. The findings also emphasise the need to consider the underlying ecosystem characteristics, including soil, topography and vegetation composition, in assessing ecosystem responses to climate change. While this research primarily concentrated on the southern African savanna as a case study, the methodological robustness of this approach enables its application to diverse arid and semi-arid biomes for the assessment of climate-ecosystem interactions that contribute to abrupt shifts.

Raised water temperature enhances benthopelagic links via intensified bioturbation and benthos-mediated nutrient cycling

Sediment reworking by benthic infauna, namely bioturbation, is of pivotal importance in expansive soft-sediment environments such as the Wadden Sea. Bioturbating fauna facilitate ecosystem functions such as bentho-pelagic coupling and sediment nutrient remineralization capacities. Yet, these benthic fauna are expected to be profoundly affected by current observed rising sea temperatures. In order to predict future changes in ecosystem functioning in soft-sediment environments like the Wadden Sea, knowledge on the underlying processes such as sediment reworking, is crucial. Here, we tested how temperature affects bioturbation and its associated ecosystem processes, such as benthic nutrient fluxes and sediment oxygen consumption, using luminophore tracers and sediment incubation cores. We used a controlled mesocosm experiment set-up with key Wadden Sea benthos species: the burrowing polychaetes Arenicola marina and Hediste diversicolor, the bivalve Cerastoderma edule, and the tube-building polychaete Lanice conchilega. The highest bioturbation rates were observed from A. marina, reaching up to 375 cm2yr−1; followed by H. diversicolor, with 124 cm2yr−1 being the peak bioturbation rate for the ragworm. Additionally, the sediment reworking activity of A. marina facilitated nearly double the amount of silicate efflux compared to any other species. Arenicola marina and H. diversicolor accordingly facilitated stronger nutrient effluxes under a warmer temperature than L. conchilega and C. edule. The oxygen uptake of A. marina and H. diversicolor within the sediment incubation cores was correspondingly enhanced with a higher temperature. Thus, increases in sea temperatures may initially be beneficial to ecosystem functioning in the Wadden Sea as faunal bioturbation is definitely expedited, leading to a tighter coupling between the sediment and overlying water column. The enhanced bioturbation activity, oxygen consumption, and facilitated nutrient effluxes from these invertebrates themselves, will aid in the ongoing high levels of primary productivity and organic matter production.

Can Exclusion of Feral Ecosystem Engineers Improve Coastal Floodplain Resilience to Climate Change? Insight from a Case Study in North East Arnhem Land, Australia.

Global climate change can interact with local drivers, such as ecosystem engineers, to exacerbate changes in ecosystem structure and function, with socio-ecological consequences. For regions of Indigenous interest, there may also be cultural consequences if species and areas affected are culturally significant. Here we describe a participatory approach between the Indigenous (Yolngu) Yirralka Rangers and non-Indigenous researchers that explored the interaction between sea level rise and feral ungulate ecosystem engineers on culturally significant floodplains in the Laynhapuy Indigenous Protected Area (IPA), northern Australia. A feral ungulate exclusion fence array (12 fenced and 12 unfenced plots) was stratified by elevation/salinity to disentangle the effects of salinity and ungulates on floodplain soil and vegetation. We found that exclusion of feral ungulates improved ground cover vegetation, which, according to our literature-derived ecosystem process model, may enhance soil trapping and reduce evapotranspiration to provide the antecedent conditions needed to improve floodplain resilience to sea level rise. The mid-zone of the supratidal floodplain study site was suggested as the region where the benefits of fencing were most pronounced after two years and ground cover species diversity was highest. Ongoing monitoring is required to investigate whether removal of feral ungulates can increase resilience against sea level rise and recruitment of eco-culturally significant Melaleuca species. An interview with a key Yolngu Traditional Owner of the study site demonstrated the importance and effectiveness of the partnership. Yolngu land owners and rangers were active co-researchers and will decide if, when and how to integrate results into feral ungulate management and climate adaptation responses, highlighting the importance of industry-university partnerships in maximising biocultural conservation outcomes.

Intraspecific leaf trait variation mediates edge effects on litter decomposition rate in fragmented forests.

There is strong trait dependence in species-level responses to environmental change and their cascading effects on ecosystem functioning. However, there is little understanding of whether intraspecific trait variation (ITV) can also be an important mechanism mediating environmental effects on ecosystem functioning. This is surprising, given that global change processes such as habitat fragmentation and the creation of forest edges drive strong trait shifts within species. On 20 islands in the Thousand Island Lake, China, we quantified intraspecific leaf trait shifts of a widely distributed shrub species, Vaccinium carlesii, in response to habitat fragmentation. Using a reciprocal transplant decomposition experiment between forest edge and interior on 11 islands with varying areas, we disentangled the relative effects of intraspecific leaf trait variation versus altered environmental conditions on leaf decomposition rates in forest fragments. We found strong intraspecific variation in leaf traits in response to edge effects, with a shift toward recalcitrant leaves with low specific leaf area and high leaf dry matter content from forest interior to the edge. Using structural equation modeling, we showed that such intraspecific leaf trait response to habitat fragmentation had translated into significant plant afterlife effects on leaf decomposition, leading to decreased leaf decomposition rates from the forest interior to the edge. Importantly, the effects of intraspecific leaf trait variation were additive to and stronger than the effects from local environmental changes due to edge effects and habitat loss. Our experiment provides the first quantitative study showing that intraspecific leaf trait response to edge effects is an important driver of the decrease in leaf decomposition rate in fragmented forests. By extending the trait-based response-effect framework toward the individual level, intraspecific variation in leaf economics traits can provide the missing functional link between environmental change and ecological processes. These findings suggest an important area for future research on incorporating ITV to understand and predict changes in ecosystem functioning in the context of global change.

Effects of Photovoltaic Power Station Construction on Terrestrial Environment： Retrospect and Prospect

With the rapid growth of global energy consumption, the environment will further deteriorate, and the competition among countries to reduce emissions will become more intense. Photovoltaic power generation using solar energy as a clean energy source is of strategic importance for achieving a carbon-neutral planet. Therein, centralized photovoltaic power stations in terrestrial ecosystems cover the earth's surface, which leads to changes in land use and has a significant effect on the surface energy balance and precipitation regimes, altering soil nutrient cycling and plant productivity, and ultimately significantly affects ecosystem functions and services. By synthesizing relevant studies on this topic over the past 20 years, we summarized the effects of photovoltaic power station construction on microclimate, soil, flora and fauna, and potential changes in terrestrial ecosystem functions. Overall, the photovoltaic power stations improved the quality of the soil condition, especially in harsh environments, and increased the vegetation coverage. In addition, photovoltaic power stations could affect ecosystem functions including plant productivity, soil erosion resistance, and soil carbon sequestration by regulating microclimatic factors such as solar radiation intensity, air temperature and humidity, wind speed, and wind direction. Although numerous studies have anticipated the potential effect of photovoltaic power stations on ecosystem structure and functions, empirical evidence remains scarce. Therefore, more studies focusing on the regional variability of the ecological impacts of photovoltaic power stations and the potential pathways of photovoltaic power stations affecting ecosystem functions are needed in the future. Improving the understanding of the ecological effects of photovoltaic power stations may help to provide a basis for ecological protection and restoration.

Morphometric variations of two patellid limpets between artificial breakwaters and natural reefs

Artificial shorelines often differ from natural reefs in shape, composition, and habitat complexity. They promote higher accumulation of pollutants and increased physiological stress, which lead to changes in species distributions and ecosystem functioning. This can promote trophic shifts and reduced genetic diversity of gastropod populations inhabiting artificial shorelines and might promote morphological changes, which may influence behaviour, vulnerability to predation, feeding efficiency, sex ratios, reproductive development, and overall fitness. This study explores inter- and intraspecific shell morphometric variations in Patella rustica and P. caerulea between breakwaters (ripraps) and natural reefs in three sites of Ceuta (North Africa, Spain), including a physicochemical assessment of the studied locations: shore orientation, inclination and wave exposure, and substratum nature, heterogeneity and roughness. Limpets on artificial substrata had a slightly smaller extra-visceral cavity and flattened shell profile, which suggests that the desiccation and temperature stress driven by the lithological composition and roughness of the studied substrata might have influenced the registered shell shape variation. However, the high morphometric variation registered for both species across sites and substrata suggests that limpets' morphology might be responding to a complex interaction of environmental and ecological factors rather than solely rock type. The findings of this study highlight the complex interplay between rock type and local environmental conditions in shaping patellid limpets’ shell morphology and provide insights into the adaptive mechanisms that drive shell shape variation in limpet populations in the face of coastal sprawl and anthropogenic global change.

Invasive poeciliids dominate fish community in a highly altered river: insights from a diversity study of riverbank fishes in Mexico

Abstract The presence of invasive species can cause significant changes in native communities and ecosystem functions. Mexico is home to 6% of all known freshwater fish species on the planet, with a high rate of endemism. Due to heavy urbanization, the Mexican Central Plateau has become one of the most densely populated areas in the world, and its Tula River is considered one of the most polluted rivers in Mexico. Our objective was to investigate whether native fish species persist in such adverse conditions and to evaluate the seasonal and spatial distribution of both native and non-native species at three sites along the Tula River. We evaluated environmental characteristics and fish community structure. We found two native species, the black fin goodea (Goodea atripinnis) and the yellow shiner (Notropis calientis). However, their abundance was extremely low across all sites and seasons. In contrast, invasive poecilids dominated the communities, accounting for 99.4% of the total abundance. Our results indicate a clear relationship between river characteristics and fish community structure, highlighting the significance of river width, river velocity, temperature, dissolved oxygen, and pH. The prevalence of invasive species underscores the urgent need for conservation efforts aimed to protect and restore native fish populations.

Evolution and zoning of spatial ecosystem functional stability in the southern hilly region of China: a “structure–function” perspective

IntroductionA series of significant ecological construction projects in the southern hilly region have brought about substantial changes to the ecological status and comprehensive zoning of the region. Hunan Province, with its strategic significance, was chosen as a representative research subject in the southern hilly region.MethodsWe conducted a dynamic evaluation of the ecological status change and comprehensive zoning of Hunan Province from a structure–function perspective by applying the transfer matrix, Theil-Sen, Mann-Kendall, and ecosystem service trade-offs or synergies methods. The research goal was to integrate and harmonize structural complexity and functional diversification, providing valuable insights for optimizing both ecological background and territorial background.ResultsThe main results are as follows: (1) The structural changes of ecosystems were mainly concentrated in settlement and Cropland ecosystems. While the area of bulti-up ecosystems has increased significantly, from 1.34% in 2000 to 2.72% in 2020. Cropland ecosystems marking a decrease of 1.39%, with a continued conversion of Cropland into construction land ecosystems. (2) Ecosystem function changes have introduced instability. Over time, NPP exhibited an oscillating trend of increase followed by a decrease. Spatially, there was a sharp decline in peripheral building land, and the regions of declining NPP displayed a lateral U-shaped distribution. (3) The overall trend in ecosystem service changes was positive. Quantitatively, GP and CS experienced an ascending-then-decreasing pattern, while HQ showed a weak decline and WY increased annually. At the county scale, there was noticeable spatial heterogeneity. Human socio-economic activities and environmental protection policies exert a significant impact on the ecological conditions within the study area. (4) Regarding the national territory space function partition, urban functional zones have primarily catered to residential functions and were mainly distributed in the Changsha-Zhuzhou-Xiangtan area.DiscussionEcological functional zones were mainly centered on ecological functions, and most were located in the mountainous areas of western and southern Hunan Province. The agricultural function areas were mainly to serve production functions and were mainly located in the Dongting Lake Plain, the nearshore plain of the mainstream and tributary systems of the rivers of Xiang, Zi, Yuan, and Li. In general, the changes in ecosystem structure and function in the study area reflect changes in ecological conditions. In the future, ecosystem diversity, stability, and sustainability should be improved from an integrated structure–function perspective.

1996-2018 Yılları Arasında Orman Ekosistemi Fonksiyonlarındaki Mekansal-Zamansal Değişimlerin Karşılaştırılması: Türkiye'den Bir Örnek Çalışma

The objective of this study was to determine the temporal changes in forest ecosystem values (economic, ecological, and socio-cultural functions) for the 1996, 2009 and 2018 planning periods. For this purpose, forest management plans and forest cover type maps were used to reveal the changes in forest ecosystem values for the planning periods. Temporal changes in forest ecosystem functions were discussed in terms of economic, ecological and socio-cultural functions which are three essential functions. There has been a decrease in the amount of area for economic purposes in the region in the following planning periods. A general decrease in areas for economic purposes and a general increase in areas for ecological purposes were determined during the planning periods. While there was not any area for socio-cultural purposes in the 1996 planning period, there was an area of 1631 ha in the 2009 planning period and 1575 ha in the 2018 planning period. Demands of the society and the changes in forest management planning approaches over time, changes have occurred in forest functions. Depending on these changes, decreased in production forests and increases in non-production forests (ecological and socio-cultural) were observed.