Importance Of Environmental Drivers Research Articles

Bacterial community composition in the Northern Gulf of Mexico intertidal sediment bioturbated by the ghost shrimp Lepidophthalmus louisianensis.

Bioturbation plays an important role in structuring microbial communities in coastal sediments. This study investigates the bacterial community composition in sediment associated with the ghost shrimp Lepidophthalmus louisianensis at two locations in the Northern Gulf of Mexico (Bay St. Louis, MS, and Choctawhatchee Bay, FL). Bacteria were analysed for shrimp burrows and for three different depths of bioturbated intertidal sediment, using second-generation sequencing of the 16S rRNA gene. Burrow walls held a unique bacterial community, which was significantly different from those in the surrounding sediment communities. Communities in burrow walls and surrounding sediment communities also differed between the two geographic locations. The burrow wall communities from both locations were more similar to each other than to sediment communities from same location. Alpha- and Gammaproteobacteria were more abundant in burrows and surface sediment than in the subsurface, whereas Deltaproteobacteria were more abundant in burrows and subsurface sediment, suggesting sediment mixing by the bioturbator. However, abundance of individual ASVs was geographic location-specific for all samples. Therefore, it is suggested that the geographic location plays an important role in regional microbial communities distinctiveness. Bioturbation appears to be an important environmental driver in structuring the community around burrows. Sampling was conducted during times of the year and water salinity, tidal regime and temperature were variable, nevertheless the structure microbial communities appeared to remain realatively stable suggesting that these environmental variable played only a minor role.

Rapid diversification of a free-living protist is driven by adaptation to climate and habitat

Microbial eukaryotes (protists) have major functional roles in aquatic ecosystems, including the biogeochemical cycling of elements as well as occupying various roles in the food web. Despite their importance for ecosystem function, the factors that drive diversification in protists are not known. Here, we aimed to identify the factors that drive differentiation and, subsequently, speciation in a free-living protist, Synura petersenii (Chrysophyceae). We sampled five different geographic areas and utilized population genomics and quantitative trait analyses. Habitat and climate were the major drivers of diversification on the local geographical scale, while geography played a role over longer distances. In addition to conductivity and temperature, precipitation was one of the most important environmental drivers of differentiation. Our results imply that flushing episodes (floods) drive microalgal adaptation to different niches, highlighting the potential for rapid diversification in protists.

Life history traits and historical comparison of blue whiting (Micromesistius poutassou) growth performance from the western Pomo/Jabuka Pits area (central Adriatic Sea)

Although fishing is considered the primary cause of the decline in fish populations, increasing evidence of the significant role of climate change has been provided recently in the Mediterranean Sea, which shows one of the highest warming trends in the world. In this area, the most important environmental driver is represented by the increase in seawater temperature. Though several studies have addressed the effects of sea warming on thermophilic species, little attention has been paid to cold-water species. Among these, blue whiting (Micromesistius poutassou) constitutes one of the most important traditional fisheries resources in the northern part of the basin, particularly in the central Adriatic Sea. This area has experienced intense fishing exploitation by the Italian and Croatian fishing fleets. Since 2015, the Pomo/Jabuka Pits area, the fleets’ main fishing ground, has been subject to a series of fishing regulations over time and space. In the present study, we investigated the age structure and growth performance (by means of otoliths) of blue whiting, comparing samples collected during 1985–86 and 2020–21 in the Pomo/Jabuka Pits. Our results show that the 2020–21 blue whiting specimens had a lower length-at-age compared to 1985–86. The asymptotic length estimate decreased from 29 cm TL in 1985–86 to 25 cm TL in 2020–21. The pattern observed might be related to a modification in the cold and dense water formation dynamics in the northern Adriatic Sea, as a consequence of climate change, resulting in higher temperatures and lower nutrient and oxygen exchange, which may have hampered the optimal growth of the species. Moreover, data on the historical trend of landings from the Adriatic Sea reveals a clear decline in catches starting from 2000 onwards. Although the introduction of a fishing ban in the Pomo/Jabuka Pits was an important milestone, the abundance of this species in the area remains at low levels, highlighting a potentially alarming situation for the stock of blue whiting in the central Adriatic Sea.

Caddisflies (Trichoptera) of Protected Calcareous Fen Habitats: Assemblages, Environmental Drivers, Indicator Species, and Conservation Issues.

The caddisflies (Trichoptera) of calcareous fen habitats, in contrast to those of other peatland types, have been poorly researched. We thus conducted a two-year study in south-eastern Poland encompassing four types of such habitats-drained and undrained fens and water bodies (pools and ditches) located within the fens-in order to define trichopteran reference assemblages (PCoA), indicator species (IndVal analysis), and the drivers (both natural and those associated with landscape management, including area protection) responsible for caddisfly species distribution (CCA). The most important environmental driver was habitat persistence. Distance-based RDA analysis revealed a distinct pattern in the distribution of species with or without diapause along the persistence gradient. Environmental drivers associated with plants were also crucial for both fens and water bodies. The key factor influencing the caddisfly assemblages of pools and ditches was the use and management of the surrounding land, whereas in the fens, it was the level of area protection. Physical and chemical water parameters had no statistically significant impact on the assemblages. Some factors can be modified by humans (e.g., water level regulation, vegetation, and landscape management) to maintain healthy ecosystems for aquatic insects.

Assessing acidity impacts in Nordic lakes and streams: Development of a macroinvertebrate-based multimetric index to quantify degradation and recovery

1)Emissions of acidifying compounds have decreased over several decades, nevertheless acidification impacts on aquatic ecosystems remains as a regionally important environmental driver resulting in biodiversity loss and impaired function in many lakes and streams.2)Many metrics based on macroinvertebrates are currently used to assess the biological impacts of acidification. However, few include measures of community composition, abundance, diversity, and the presence/absence of tolerant/sensitive taxa, and fewer still are calibrated simultaneously for both lentic and lotic waters and across large geographic regions.3)Data on water chemistry and benthic macroinvertebrates was extracted from a database compiled by representatives from Norway, Sweden and Finland. Using lake- and stream data on water chemistry and macroinvertebrates from Norway and Sweden, we developed a Nordic macroinvertebrate-based multimetric index (MMI) for acidity (NAMI) to assess impacts of and recovery from acidity using information on measures of community structure and traits.4)Lake and stream datasets were explored together and independently for correlation between measures of community structure and traits to acid neutralizing capacity (ANC), modified ANC regarding 1/3 of the organic acids as strong (ANCo1) and pH. Significantly correlated candidate metrics with highest correlations were chosen using forward stepwise linear regression models against ANC, ANCo1 and pH. Results showed that the combined lake and stream MMI had the highest correlation (r-squared) with ANCo1.5)Seven metrics were included in NAMI: one measure of composition (sum of the combined relative abundance of Gastropoda, Bivalvia and Crustacea), two measures of diversity (the number of Ephemeroptera taxa excluding leptophlebiids and the number of Bivalvia taxa), one effect trait (taxa with life cycle duration > 1 year), two response traits (taxa with resistance forms: eggs and plastron respiration) and one tolerance trait (preference > 5 pH < 5.5).6)The NAMI is a promising metric to standardize lake and stream macroinvertebrate assessments of acidity impacts and recovery across the Nordic countries, and to harmonize chemical and biological classifications of water quality, including progress towards achieving international objectives.

Macrobenthic fauna of the Agulhas Bank shelf edge

The deep sea (>200m depth) off South Africa is largely unexplored, with most benthic macrofauna samples limited to depths shallower than 100m. The benthic infaunal diversity of the Agulhas Bank shelf edge has not yet been studied. We analysed seven grab samples that were opportunistically collected along the shelf edge at depths of 290-533 m. A total of 136 macrofauna items representing 75 species were identified, and the first species list of the infauna of the shelf edge was compiled, Polychaetes comprised 48% of total abundance, and the sites had an average similarity of 7% based on species abundance, Spearman rank correlation showed that depth and sediment particle size are important environmental drivers of community abundance and biomass variation on the shelf edge, Habitat heterogeneity is likely high along the Agulhas Bank shelf edge, Greater sampling effort in habitats for which data are scarce provides crucial information for offshore biodiversity assessment and management

An inexpensive method for reliable recovery of stream temperature data

AbstractObjectiveWater temperature is perhaps the single‐most important environmental driver of fish populations. The strong relationship between fish and water temperature allows fisheries managers to make predictions about the influence of temperature on fishes under both current and future climatic conditions. These predictions are more robust if based on year‐round and long‐term data. However, water temperature data are commonly compromised or lost altogether when data‐logging temperature sensors are damaged or go missing. In recognition of the need for reliable ways to collect long‐term, year‐round temperature data, we designed, implemented, and tested a durable but cryptic logger deployment and retrieval system.MethodsWe used metal housings and stakes to protect and anchor temperature loggers on the streambed and, when necessary, used a metal detector to assist with logger recovery. We then evaluated logger recovery rates across 12 years and 312 deployments at 85 sites in first‐ to ninth‐order Rocky Mountain streams and rivers.ResultAlthough we recovered only 73% of loggers with traditional means of retrieval (e.g., GPS or photo), presumably owing to the inconspicuous nature of our metal housings and streambed anchor stakes, we recovered 96% of loggers when a metal detector was also used. Ordinal and binary logistic regression revealed that a metal detector was especially beneficial when trying to recover loggers from unfamiliar monitoring sites or those deployed for long periods of time (years).ConclusionOur methods could be replicated for a reliable and inexpensive approach to acquiring year‐round stream temperature data.

Grassland ecosystem type drives AM fungal diversity and functional guild distribution in North American grasslands.

Nutrient exchange forms the basis of the ancient symbiotic relationship that occurs between most land plants and arbuscular mycorrhizal (AM) fungi. Plants provide carbon (C) to AM fungi and fungi provide the plant with nutrients such as nitrogen (N) and phosphorous (P). Nutrient addition can alter this symbiotic coupling in key ways, such as reducing AM fungal root colonization and changing the AM fungal community composition. However, environmental parameters that differentiate ecosystems and drive plant distribution patterns (e.g., pH, moisture), are also known to impact AM fungal communities. Identifying the relative contribution of environmental factors impacting AM fungal distribution patterns is important for predicting biogeochemical cycling patterns and plant-microbe relationships across ecosystems. To evaluate the relative impacts of local environmental conditions and long-term nutrient addition on AM fungal abundance and composition across grasslands, we studied experimental plots amended for 10 years with N, P, or N and P fertilizer in different grassland ecosystem types, including tallgrass prairie, montane, shortgrass prairie, and desert grasslands. Contrary to our hypothesis, we found ecosystem type, not nutrient treatment, was the main driver of AM fungal root colonization, diversity, and community composition, even when accounting for site-specific nutrient limitations. We identified several important environmental drivers of grassland ecosystem AM fungal distribution patterns, including aridity, mean annual temperature, root moisture, and soil pH. This work provides empirical evidence for niche partitioning strategies of AM fungal functional guilds and emphasizes the importance of long-term, large scale research projects to provide ecologically relevant context to nutrient addition studies.

Environmental drivers and interaction mechanisms of heavy metal and antibiotic resistome exposed to amoxicillin during aerobic composting.

The environmental accumulation and spread of antibiotic resistance pose a major threat to global health. Aerobic composting has become an important hotspot of combined pollution [e.g., antibiotic resistance genes (ARGs) and heavy metals (HMs)] in the process of centralized treatment and resource utilization of manure. However, the interaction mechanisms and environmental drivers of HMs resistome (MRGs), antibiotic resistance (genotype and phenotype), and microbiome during aerobic composting under the widely used amoxicillin (AMX) selection pressure are still poorly understood. Here, we investigated the dynamics of HMs bioavailability and their MRGs, AMX-resistant bacteria (ARB) and antibiotic resistome (ARGs and intI1), and bacterial community to decipher the impact mechanism of AMX by conducting aerobic composting experiments. We detected higher exchangeable HMs and MRGs in the AMX group than the control group, especially for the czrC gene, indicating that AMX exposure may inhibit HMs passivation and promote some MRGs. The presence of AMX significantly altered bacterial community composition and AMX-resistant and -sensitive bacterial structures, elevating antibiotic resistome and its potential transmission risks, in which the proportions of ARB and intI1 were greatly increased to 148- and 11.6-fold compared to the control group. Proteobacteria and Actinobacteria were significant biomarkers of AMX exposure and may be critical in promoting bacterial resistance development. S0134_terrestrial_group was significantly negatively correlated with blaTEM and czrC genes, which might play a role in the elimination of some ARGs and MRGs. Except for the basic physicochemical (MC, C/N, and pH) and nutritional indicators (NO3 --N, NH4 +-N), Bio-Cu may be an important environmental driver regulating bacterial resistance during composting. These findings suggested the importance of the interaction mechanism of combined pollution and its synergistic treatment during aerobic composting need to be emphasized.

Twenty-year record of white pox disease in the Florida Keys: importance of environmental risk factors as drivers of coral health.

Declining coral populations worldwide place a special premium on identifying risks and drivers that precipitate these declines. Understanding the relationship between disease outbreaks and their drivers can help to anticipate when the risk of a disease pandemic is high. Populations of the iconic branching Caribbean elkhorn coral Acropora palmata have collapsed in recent decades, in part due to white pox disease (WPX). To assess the role that biotic and abiotic factors play in modulating coral disease, we present a predictive model for WPX in A. palmata using 20 yr of disease surveys from the Florida Keys plus environmental information collected simultaneously in situ and via satellite. We found that colony size was the most influential predictor for WPX occurrence, with larger colonies being at higher risk. Water quality parameters of dissolved oxygen saturation, total organic carbon, dissolved inorganic nitrogen, and salinity were implicated in WPX likelihood. Both low and high wind speeds were identified as important environmental drivers of WPX. While high temperature has been identified as an important cause of coral mortality in both bleaching and disease scenarios, our model indicates that the relative influence of HotSpot (positive summertime temperature anomaly) was low and actually inversely related to WPX risk. The predictive model developed here can contribute to enabling targeted strategic management actions and disease surveillance, enabling managers to treat the disease or mitigate disease drivers, thereby suppressing the disease and supporting the persistence of corals in an era of myriad threats.

Crustaceans of the Northwest Pacific Ocean: Species richness and distribution patterns

Biodiversity patterns of marine crustaceans are still unknown in many locations or might have been overlooked due to our knowledge gaps, despite increasing sampling and data sharing efforts during the last decades. By analysing big data extracted from open portals such as Ocean Biodiversity Information System (OBIS) and Global Biodiversity Information System (GBIF), we aim to revisit the distribution and biodiversity patterns of the highly speciose and abundant Crustacea in the Northwest Pacific (NWP) from shallowest depths to the deep sea. This study focussed on selected benthic and pelagic crustacean (sub) classes and their species richness, sampling effort, and expected species richness (ES50) using equal/sized hexagonal cells, 5° latitudinal bands, 500 m depth intervals were analyzed. Crustacean species richness was highest in the tropical Philippines as well as around the Japanese islands. Pelagic crustacean species richness peaked at 30° latitude and declined beyond that. Benthic taxa; however, depicted high levels of species richness across most of the latitudinal gradient, reaching its highest point at 45° latitude. Due to the prevalence of certain crustacean orders in the deep sea, benthic species richness showed a distribution pattern with two distinct peaks across bathymetric gradients; with highest species richness recorded at shallow-water depths and also at abyssal depths. The most important environmental drivers of benthic and pelagic crustacean species richness were primary productivity (positive correlation) and salinity (negative correlation). Our study provides first insights into biodiversity patterns of the highly diverse Crustacea in the NWP and highlights strong differences between benthic and pelagic taxa. The results presented here could help us to better understand whether benthic or pelagic taxa might respond differently to climate changes in the NWP based on their distinct physiological and biological characteristics. This information is crucial in establishing species management strategies and ecosystem restorations in both shallow water and deep-sea environments.

Climate Adaptive Management in the Northeastern United States: Common Strategies and Motivations of Rural and Urban Foresters

AbstractDespite the mounting imperative for managers to help forests adapt to the rapidly shifting climate and related stressors, significant gaps remain between recommendations for adaptive forest management and its actual implementation across the globe. The research presented here offers a novel qualitative analysis regarding the current nature, extent, and drivers of adaptive management in the northeastern United States. Based on 32 in-depth semi-structured interviews with rural (n = 17) and urban foresters (n = 15) across New England and New York, we share a summary of (1) important environmental drivers of adaptation across the region, (2) commonly employed adaptive strategies, (3) significant barriers to adaptation, and (4) approaches to working through named barriers. We categorize adaptive practices of foresters as options of resistance, resilience, or transition, highlighting opportunities to increase the use of all three options across the landscape.

Browning affects pelagic productivity in northern lakes by surface water warming and carbon fertilization.

Global change impacts important environmental drivers for pelagic gross primary production (GPP) in northern lakes, such as temperature, light, nutrient, and inorganic carbon availability. Separate and/or synergistic impacts of these environmental drivers on pelagic GPP remain largely unresolved. Here, we assess key drivers of pelagic GPP by combining detailed depth profiles of summer pelagic GPP with environmental and climatic data across 45 small and shallow lakes across northern Sweden (20 boreal, 6 subarctic, and 19 arctic lakes). We found that across lakes summer pelagic GPP was strongest associated with lake water temperatures, lake carbon dioxide (CO2 ) concentrations impacted by lake water pH, and further moderated by dissolved organic carbon (DOC) concentrations influencing light and nutrient conditions. We further used this dataset to assess the extent of additional DOC-induced warming of epilimnia (here named internal warming), which was especially pronounced in shallow lakes (decreasing 0.96°C for every decreasing m in average lake depth) and increased with higher concentrations of DOC. Additionally, the total pools and relative proportion of dissolved inorganic carbon and DOC, further influenced pelagic GPP with drivers differing slightly among the boreal, subarctic and Arctic biomes. Our study provides novel insights in that global change affects pelagic GPP in northern lakes not only by modifying the organic carbon cycle and light and nutrient conditions, but also through modifications of inorganic carbon supply and temperature. Considering the large-scale impacts and similarities of global warming, browning and recovery from acidification of lakes at higher latitudes throughout the northern hemisphere, these changes are likely to operate on a global scale.

Process-explicit models reveal the structure and dynamics of biodiversity patterns

With ever-growing data availability and computational power at our disposal, we now have the capacity to use process-explicit models more widely to reveal the ecological and evolutionary mechanisms responsible for spatiotemporal patterns of biodiversity. Most research questions focused on the distribution of diversity cannot be answered experimentally, because many important environmental drivers and biological constraints operate at large spatiotemporal scales. However, we can encode proposed mechanisms into models, observe the patterns they produce in virtual environments, and validate these patterns against real-world data or theoretical expectations. This approach can advance understanding of generalizable mechanisms responsible for the distributions of organisms, communities, and ecosystems in space and time, advancing basic and applied science. We review recent developments in process-explicit models and how they have improved knowledge of the distribution and dynamics of life on Earth, enabling biodiversity to be better understood and managed through a deeper recognition of the processes that shape genetic, species, and ecosystem diversity.

Patterns of variation in plant diversity vary over different spatial levels in seasonal coastal wetlands

AbstractAimTo quantify the responses of alpha and beta diversity to multivariate gradients, incorporating variation in environmental and management variability in coastal dune slacks.LocationUnited Kingdom dune slacks.MethodsPlant community composition, plant nutrient status and soil characteristics were measured for 164 quadrats in 41 dune slacks across 12 coastal sand dune systems. Data were collated on climate and atmospheric deposition. Hydrological regimes at daily resolution were modelled and calibrated using daily‐to‐monthly site measurements, from which we calculated quadrat‐level hydrological metrics. Alpha diversity (richness, Shannon diversity and Pielou's evenness) metrics and beta diversity (turnover and nestedness) for species and genera were calculated across three spatial levels from sand dune system (highest) to dune slack to quadrat (lowest).ResultsDiversity patterns depended on the spatial and taxonomic level considered. At smaller spatial levels (between dune slacks and between quadrats), alpha and beta diversity varied along gradients driven by soil characteristics, water table depth and atmospheric deposition. At larger spatial levels (between sand dune systems), patterns of beta diversity were a consequence of plant nutrient status. There was little variability in alpha diversity along this same gradient, with only small changes in Pielou's species evenness. Patterns at a coarser taxonomic level (genus) mirrored those at the species level.Main conclusionWe show that patterns of variation in plant diversity are dependent on the spatial level considered, but taxonomic level made little difference in understanding these patterns. Therefore, if we do not consider patterns across different spatial levels, important environmental and management drivers could be missed. The high biodiversity value and degree of threat to these European protected habitats makes such understanding invaluable for their conservation.

Biotic predictors improve species distribution models for invasive plants in Western U.S. Forests at high but not low spatial resolutions

Invasions by non-native plants threaten forest health and sustainability. The ability to predict areas at greatest risk to invasion is essential for informing both monitoring and management of invasive species. Species distribution models (SDMs) are often used to identify environmental correlates of a species’ occurrence and predict geographic areas that may be suitable for its presence and are commonly constructed using solely abiotic predictors. However, mounting evidence implies that not including biotic predictors in SDMs may yield less accurate models at some resolutions typical of landscape-scale models, although this possibility has rarely been evaluated in invasive plants. In this study, we determined whether including descriptors of the biotic environment improved the accuracy of SDMs built at five decreasing spatial resolutions for infestations of five common invasive plants in forests of California, Oregon, and Washington, USA and described environmental correlates of each species’ presence.Predictors of occurrence often echoed those identified in previous studies of the focal species, indicating that our models accurately identified important environmental drivers of occurrence. Including biotic predictors in the SDMs consistently improved model accuracy only at the highest resolution we examined, which may be due to the spatial scale at which biotic interactions primarily act to constrain species’ distributions, the particular biotic predictors we used in our models, or correlations between attributes of the abiotic and biotic environment. This finding suggests that, while the practice of building SDMs using abiotic predictors alone may generally yield models whose accuracy does not differ substantially from those that also include biotic predictors, the effects of biotic interactions on the distribution of invasive plants in forests may be detectable at larger scales than previously thought.

Risk assessment and identification of factors influencing the historical concentrations of microcystin in Lake Taihu, China

Understanding the history of microcystins (MCs) pollution in large lakes can help inform future lake management. We collected sediment cores from Lake Taihu to: investigate the long-term record of MCs (MC-LR, MC-YR, and MC-RR), explore the main environmental drivers of MCs, and assess their public health and ecological risks. Results showed that MCs content in all cores increased over time. The core from north Taihu had the highest MC concentrations, with an average total MCs (sum of MC-LR, MC-YR, and MC-RR = TMCs) content of (74.31±328.55) ng/g. The core from eastern Taihu showed the lowest average TMCs content of (2.91±3.95) ng/g. PCA showed that sediment MCs at the three sites were positively correlated with sediment chlorophyll-a. MC-LR and MC-YR in northern and western Taihu negatively correlated with both the sediment total organic carbon/sediment total nitrogen ratio (STOC/STN) and water nitrate (NO3−-N) concentration, but three MC congeners at eastern Taihu showed positive correlations with water orthophosphate (PO43−-P), NO3−-N, and STOC/STN. Generalized additive model analysis at each site revealed that NO3−-N was the main TMCs driver in northern and western Taihu where phytoplankton dominated, whereas PO43−-P was the main TMCs driver in eastern Taihu where macrophytes dominated. At the whole lake scale, total phosphorus (TP) and PO43−-P were the most important environmental drivers influencing MCs; TP explained 47.4%, 44.2%, and 47.6% while orthophosphate explained 34.8%, 31.2%, and 34.7% of the deviance on TMCs, MC-LR, and MC-YR, respectively. NO3−-N also showed a strong effect on MCs variation, especially on MC-YR. Risk assessment showed that both ecological and public health risk has increased in recent years. We conclude that while control of phosphorus and nitrogen input should be a major focus for future lake management, lake zone-specific management strategies may also be important.

The Environmental Drivers of Benthic Fauna Diversity and Community Composition

Establishing management programs to preserve the benthic communities along the NW Pacific and the Arctic Ocean (AO) requires a deep understanding of the composition of communities and their responses to environmental stressors. In this study, we thus examine patterns of benthic community composition and patterns of species richness along the NW Pacific and Arctic Seas and investigate the most important environmental drivers of those patterns. Overall we found a trend of decreasing species richness toward higher latitudes and deeper waters, peaking in coastal waters of the eastern Philippines. The most dominant taxa along the entire study area were Arthropoda, Mollusca, Cnidaria, Echinodermata, and Annelida. We found that depth, not temperature, was the main driver of community composition along the NW Pacific and neighboring Arctic Seas. Depth has been previously suggested as a factor driving species distribution in benthic fauna. Following depth, the most influential environmental drivers of community composition along the NW Pacific and the Arctic Ocean were silicate, light, and currents. For example, silicate in Hexactinellida, Holothuroidea, and Ophiuroidea; and light in Cephalopoda and Gymnolaemata had the highest correlations with community composition. In this study, based on a combination of new samples and open-access data, we show that different benthic communities might respond differently to future climatic changes based on their taxon-specific biological, physiological, and ecological characteristics. International conservation efforts and habitat preservation should take an adaptive approach and apply measures that take the differences among benthic communities in responding to future climate change into account. This facilitates implementing appropriate conservation management strategies and sustainable utilization of the NW Pacific and Arctic marine ecosystems.

Late Holocene volcanic and human impacts on the mountain vegetation in central Sumatra, Indonesia

The Kerinci Seblat National Park (KSNP) has been a region of great significance for palynological studies featuring the combination of unique tropical vegetation, tectonics determining frequent volcanic eruptions, and a long settlement history. This palynological study aims at reconstructing ecosystem processes and is based on a long-term analysis of vegetation composition in the mountainous region of Sumatra. The research question focused on the influence of natural disturbance such as climate and volcanism, and anthropogenic impacts and fire on vegetation dynamics in the KSNP in the Sumatran highlands. A 2300-year-old lake sediment record of Danau Belibis at 2078 m asl. provides insights into the changes in vegetation composition over time in a mountainous tropical rainforest region in Jambi province. Over the entire record, Taxus was the most dominant genus. Volcanic eruptions caused continuous competition between volcanophile taxa like Casuarina and Myrica, and primary forest taxa. Settlements and agricultural activity are represented throughout the whole record. Forest clearings for wood exploitation and cultivation took place in the period from 1600 to 1000 years BP and from 600 years BP to the present. Crops were already introduced at the beginning of the record in the Kerinci highland region. The charcoal record illustrates only occasional fire events caused by natural forces. Our findings refer to the vulnerability of vegetation dynamics concerning important environmental drivers and suggest volcanic events as an important factor for environmental changes in the highlands of Sumatra.

Environmental drivers of above-ground biomass in semi-arid rangelands

Above-ground biomass (AGB), as a key biophysical and functional parameter of rangeland ecosystems, plays an important role in ecosystem carbon (C) stocks. The aim of this study was to explore the important environmental drivers of AGB in an arid rangeland by using structural equation modelling (SEM). Vegetation and soil (physical and chemical properties) were sampled using randomised-systematic methods within sampling plots. The topographic (elevation, slope, aspect, hillshade (i.e. a technique for showing the topographical shape of hills and mountains to indicate relative slopes and mountain ridges)) and climatic (mean temperature (MT), mean precipitation (MP), actual evapo-transpiration (AET) and land-surface temperature (LST)) properties were extrapolated using a raster-based digital elevation-model (DEM) map, and their values extracted at each sampling plot. SEM was then applied to assess the direct and indirect impacts of environmental factors on AGB. The AGB was directly affected by soil (41%, P &lt; 0.05) and climatic properties (34%, P &lt; 0.05). The effect of topographical factors on AGB was non-significant (P &gt; 0.05). However, climatic properties were directly affected by topographical properties, with a path coefficient of 34%. Among soil properties, nitrogen, phosphorus and potassium concentrations, silt content and soil pH were the key factors affecting AGB. Climatic variables (MT, MP) were equally effective in explaining the climate latent variable (with loading factors of −0.97 and 0.99 respectively) and AGB changes. This study highlighted the importance of soil and climatic properties in AGB variation. SEM simplified and revealed the complex relationships among ecosystem components affecting AGB, which could assist proper management of rangelands.