Discussions of the factors regulating nutrient recycling by consumers have focused on predictions from Ecological Stoichiometry (ES) and the Metabolic Theory of Ecology (MTE). ES posits that imbalances between the composition of an animal’s body tissues and its diet should determine its nutrient excretion rates, whereas the MTE predicts that excretion should directly reflect metabolic activity arising from body size and temperature. Each framework has been supported by data, but they are rarely tested together. In this study, we measured excretion rates of nitrogen (NH4), phosphorus (SRP) and N:P excretion ratio, body N:P stoichiometry, body size, and temperature for 12 species of fish from an Atlantic rainforest stream in Brazil. We fitted 8 competing models reflecting different combinations of ES (body N:P, armor classification, diet group) and MTE (body size, temperature) variables. For both N and P excretion, as well as excreted N:P ratio, only body size was included in the best model, and interspecific differences in size-scaling were greater for N than for P. Fitted size scaling coefficients were lower than the MTE prediction of 0.75 for both N (0.59, 95% CI = 0.45, 0.73) and P (0.56, 95% CI = 0.40, 0.77). There was only weak evidence that body armor in 3 of 12 species led to more retention of P, and there was no discernable effect of diet group, body N:P, or water temperature. We conclude that differences in nutrient excretion among species within a shared environment primarily reflect contrasts in metabolic rates arising from body size, rather than disparities between consumer and resource stoichiometry. Our findings align with those from other ecosystems and synthesis across aquatic taxa, expanding support for the MTE as the primary framework for predicting nutrient excretion rates. Key words: ecological stoichiometry, metabolic ecology, animals, nitrogen, phosphorus, freshwater.

Ecological restoration of former agricultural land can improve soil condition, recover native vegetation, and provide fauna habitat. However, restoration benefits are often associated with time lags, as many attributes, such as leaf litter and coarse woody debris, need time to accumulate. Here we experimentally tested whether adding fine and coarse woody debris to a decade-old restoration sites can accelerate restoration benefits. We used a Multi-site Before-After / Control-Impact design to test the effects on 30 response variables over a period of two years, including those describing soil physical and biochemical properties, herbaceous vegetation and ant communities. We analysed the data using linear mixed-effect models and perMANOVAs. Of the 30 response variables, a significant effect of mulch or log additions was found for just four variables: volumetric water content, decomposition of tea leaves, native herbaceous species cover and species richness of opportunistic ants. Mulch addition had a positive effect on soil moisture when compared to controls but suppressed growth of native (but not exotic) herbaceous plants. Whilst other soil properties such as organic matter and dissolved organic carbon showed a positive response to mulch addition, the effect was not statistically significant. On plots with log additions, decomposition rates of tea leaves decreased, and species richness of opportunistic ants increased. However, we found no effect on total species richness and abundance of other ant functional groups. The benefit of mulch to soil moisture was offset by its disbenefit to native herbs in our study. Logs increased species richness of opportunistic ants, but given time, may provide habitat for cryptic species. Indeed, benefits to other soil biophysical properties, vegetation and ant fauna may require longer timeframes to be detected. Further research is needed to determine whether the type, quantity and context of mulch and log additions may improve restoration outcomes.

Environmental temperature is a key driver of malaria transmission dynamics. Using detailed temperature records from four sites (1800-3200m) in the western Himalaya, we model how temperature regulates parasite development rate (the inverse of the extrinsic incubation period, EIP) in the wild. Using a Briére parametrization of the EIP, combined with Bayesian parameter inference, we study the thermal limits of transmission for avian (P. relictum) and human Plasmodium parasites (P. vivax and P. falciparum) as well as for two malaria-like avian parasites, Haemoproteus and Leucocytozoon. We demonstrate that temperature conditions can substantially alter the incubation period of parasites at high elevation sites (2600-3200m) leading to restricted parasite development or long transmission windows. We then compare estimates of EIP based on measures of mean temperature versus hourly temperatures to show that EIP days vary in cold versus warm environments. We found that human Plasmodium parasites experience a limited transmission window at 2600m. In contrast, for avian Plasmodium transmission was not possible between September to March at 2600m. In addition, temperature conditions suitable for both Haemoproteus and Leucocytozoon transmission were obtained from June to August and in April, at 2600m. Finally, we use temperature projections from a suite of climate models to predict that by 2040, high elevation sites (~ 2600 m) will have a temperature range conducive for malaria transmission, albeit with a limited transmission window. Our study highlights the importance of accounting for fine-scale thermal effects in the expansion of the range of the malaria parasite with global climate change.

Human disturbance directly affects animal populations but indirect effects of disturbance on species behaviors are less well understood. Camera traps provide an opportunity to investigate variation in animal behaviors across gradients of disturbance. We used camera trap data to test predictions about predator-sensitive behavior in three ungulate species (caribou Rangifer tarandus; white-tailed deer, Odocoileus virginianus; moose, Alces alces) across two boreal forest landscapes varying in disturbance. We quantified behavior as the number of camera trap photos per detection event and tested its relationship to predation risk between a landscape with greater industrial disturbance and predator abundance (Algar) and a “control” landscape with lower human and predator activity (Richardson). We also assessed the influence of predation risk and habitat on behavior across camera sites within the disturbed Algar landscape. We predicted that animals in areas with greater predation risk (more wolf activity, less cover) would travel faster and generate fewer photos per event, while animals in areas with less predation risk would linger (rest, forage), generating more photos per event. Consistent with predictions, caribou and moose had more photos per event in the landscape where predation risk was reduced. Within the disturbed landscape, no prey species showed a significant behavioral response to wolf activity, but the number of photos per event decreased for white-tailed deer with increasing line of sight (m) along seismic lines (i.e. decreasing visual cover), consistent with a predator-sensitive response. The presence of juveniles was associated with shorter behavioral events for caribou and moose, suggesting greater predator sensitivity for females with calves. Only moose demonstrated a positive association with vegetation productivity (NDVI), suggesting that for other species influences of forage availability were generally weaker than those from predation risk. Behavioral insights can be gleaned from camera trap surveys and provide information about animal responses to predation risk and the indirect impacts of human disturbances.

Submerged macrophytes play a key role in maintaining a clear-water phase and promoting biodiversity in shallow aquatic ecosystems. Since their abundance has declined globally due to anthropogenic activities, it is important to include them in aquatic ecosystem restoration programs. That macrophytes establish in early spring is crucial for maintaining the macrophyte communities for the remainder of the year. However, factors affecting this early establishment of submerged macrophytes have not been fully explored yet. Here, we conducted an outdoor experiment from winter to early spring using the submerged macrophytes Potamogeton crispus and Vallisneria spinulosa to study the effects of shading, nutrient loading, snail herbivory (Radix swinhoei) and their interactions on the early growth and stoichiometric characteristics of macrophytes. The results show that the effects strongly depend on macrophyte species. Biomass and number of shoots of P. crispus decreased, and internode length increased during low light conditions, but were not affected by nutrient loading. P. crispus shoot biomass and number showed hump-shaped responses to increased snail biomass under full light. In contrast, the biomass of the plant linearly decreased with snail biomass under low light. This indicates an interaction of light with snail herbivory. Since snails prefer grazing on periphyton over macrophytes, a low density of snails promoted growth of P. crispus by removing periphyton competition, while herbivory on the macrophyte increased during a high density of snails. The growth of V. spinulosa was not affected by any of the factors, probably because of growth limitation by low temperature. Our study demonstrates that the interaction of light with snail herbivory may affect establishment and growth of submerged macrophytes in early spring. Macrophyte restoration projects may thus benefit from lowering water levels to increase light availability and making smart use of cold-adapted herbivores to reduce light competition with periphyton.

Eryngium maritimum L. (Apiaceae) is a geophyte that inhabits in the dunes of the Mediterranean and Atlantic. In Northern Europe, it is considered a highly endangered species due to reproductive problems, while in the Mediterranean, populations are in a good state of conservation. Although it is a highly entomophilous species, there is little literature on its pollinators. The aim of this study is to analyse the role played by E. maritimum in the dune pollination network of the Balearic Islands. For this purpose, two populations located in the North and South of Mallorca were chosen, in which diurnal transects were carried out to observe and capture pollinators on 15 plant species during the anthesis period of E. maritimum. In parallel, an analysis of the flowering period of 10 of these plant species was carried out to identify periods of competition. A total of 82 pollinator species were found, belonging to 30 different families. Eryngium maritimum is a strongly generalist species, with a total of 46 pollinator species. Functionally, Teucrium dunense and Helichrysum stoechas are functionally the most similar species to E. maritimum. However, analysis of phenology suggests that these three species have been able to decouple their blooms to avoid competition. The present study shows that E. maritimum plays a key role in the dune pollination network, being its anthesis located at the end of the dune flowering season, when there are no functionally similar species in flower.

Abstract Insect population dynamics are the result of an interplay between intraspecific competition, trophic interactions and external forces such as weather conditions, but studying how these processes combine to determine population change is challenging. We investigate mechanisms of population dynamics in a natural, low density insect population. Eggs and larvae of the noctuid moth, Abrostola asclepiadis, develop on its host plant during summer. The population density, and mortality, was closely monitored throughout this period during 15 years. Densities fluctuated between one and two orders of magnitude. Egg -- larval developmental time varied substantially among years, with lower survival in cool summers with slower development. This was presumably due to the prolonged exposure to a large guild of polyphagous arthropod enemies. We also found a density dependent component during this period, that could be a result of intraspecific competition for food among old larvae. Dynamics during the long period from pupation in late summer through winter survival in the ground to adult emergence and oviposition the next year displayed few clear patterns and more unexplained variability, thus giving a more random appearance. The population hence shows more unexplained or unpredictable variation during the long wintering period, but seems more predictable over the summer egg-larval period. Our study illustrates how weather - via a window of exposure to enemies and in combination with density-dependent processes - can determine the course of population change through the insect life cycle.

Intensified inter-annual precipitation fluctuation has profoundly altered the structure and functioning of grassland ecosystems. However, it remains elusive how fertilisation and arbuscular mycorrhizal (AM) fungi affect plant communities under a variable precipitation regime. We tested the interactive effects of inter-annual precipitation fluctuation, nutrient addition (nitrogen, N and phosphorus, P) and suppression of AM fungi on aboveground net primary productivity (ANPP) and the species composition of plant community of a desert steppe for two consecutive years (2019 and 2020). Our study demonstrated that inter-annual precipitation fluctuation had a greater impact on ANPP and the species composition of plant community than N and P addition and AM fungi, suggesting that the impacts of fertilisation and AM fungi varied by year and may be difficult to predict over time. In a normal year (2019), N and P inputs altered the ANPP and the species composition of plant community via enhancing the biomass and dominance of annual species but had few impacts on the same parameters in a dry year (2020). AM fungi had only a minimal effect on plant communities across the two years. P input alone slightly enhanced plant species richness and diversity. Our results indicate that plant community responses to nutrient enrichment and AM fungi could be changed by inter-annual precipitation fluctuation and that precipitation is a key factor affecting plant communities in desert steppe.

Dispersive movements are often thought to be multicausal and driven by individual body size, sex, conspecific density, environmental variation and/or other factors. Yet such factors rarely account for most of the variation present among dispersive movements in nature, leaving open the possibility that dispersion might be indeterministic and vary in response to environmental stochasticity. We assessed the amount of variation in movement distances that could be accounted for by potential predictors of dispersal with a large empirical dataset of movement distances performed by Fowler’s Toads (Anaxyrus fowleri) on the northern shore of Lake Erie at Long Point, Ontario (2002 – 2021, incl.). These toads are easy to sample repeatedly, can be identified individually and undertake dispersive movements parallel to the shoreline on a daily basis as they forage at night. Using a linear mixed-effect model that incorporated random effect terms to account for sampling variance and inter-year environmental variation, we found that all potential predictors of dispersive movements of these animals were, at best, weak predictors that accounted for virtually none of the variation observed among movement distances. We also used linear regression models to test for the impact of environmental stochasticity on dispersive movements and identified a strong positive correlation between the distribution of toad movement distances and variability in lake water level. We conclude that deterministic proximal factors, whether intrinsic or extrinsic, neither can be shown nor are necessary to drive dispersive movements in this population. Variation in dispersive movements can be ascribed, instead, to environmental unpredictability, consistent with nomadism.

Parasite induced changes in host behavior is considered adaptive if it provides a reproductive advantage to the parasite. The entomopathogenic fungi are a fascinating group of arthropod parasites that exhibit enormous diversity in terms of both host choice and reproductive strategy, some of which actively manipulate the behavior of their host as a means to increase reproductive success. Here we focus on anamorphs of the genus Torrubiella, namely Gibellula spp., which are all obligate pathogens of spiders that kill their hosts in locations suspiciously ideal for fungal reproduction and propagation. In a final, eerily purposeful act, hosts reliably spin a thin stratum of web on the under-surface of a leaf to which they secure themselves immediately before death. We provide both theoretical and empirical lines of evidence that this phenomenon represents an extended phenotype of parasite genes analogous to those observed in other taxonomically related parasite-host systems. We argue that observations of spiders killed by Gibellula sp. both in the field (in situ) and the laboratory (in vitro), as well as this species’ close phylogenetic relation to other fungal lineages believed or suspected to influence host behavior, are strong evidence for the presence of adaptive manipulation.

Previous studies have demonstrated positive net primary production effects with in-creased precipitation in semi-arid grasslands of Inner Mongolian. The knowledge of the store and storage potential of carbon (C) and nitrogen (N) can help us to under-stand how ecosystems would respond to anthropogenic disturbances under different management strategies. Therefore, we carried out research on the storage of organic C and N in four sites where the floras and landform were similar but the intensities of disturbance by grazing animals varied. The primary objective of this study was to pinpoint how the store and storage potential of C and N would respond to grazing exclusion and precipitation. We determined concentrations of both soil organic car-bon (SOC) and soil total nitrogen (TN) in the 0–50 cm soil layers. Concentrations of microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were measured by an innovative method in our study. Additionally, soil bacteria and fungi content were determined in the 0–50 cm soil layers. The total C , N , MBC and MBN storage were significantly different among the four grasslands (P<0.05), and they all decreased substantially with grassland degradation and increased to a significant extent with the introduction of natural grassland (ND). More than 90% C and 95% N stored in soil were lost, while they were minor in other pools (including those stored in above-ground biomass, litter, and roots). It is inter-esting to note that micro-aggregate is a limiting factor to soil and microbial nutrients pool compared to precipitation. The limit range of C and N storage observed in these grassland soils suggests that enclosed-fence may be a valuable mechanism of seques-tering C in the top meter of the soil profile. The results of this study can provide a basis for better recovery of grassland that grazing disturbed in semi-arid areas.

1 Understanding the effect of ground types on foraging movements of ground-dwelling arthropods is a key step to managing their spatial distribution as required for successful conservation biological control. Indeed, fine movements at the centimetre scale can strongly influence the foraging ability of pest predators. However, because RFID or harmonic tracking techniques are not yet suitable for small species and video tracking focuses on uniform and light backgrounds, foraging movements have rarely been studied in relation to ground types. 2 We present a method to track a ground-dwelling arthropod (the earwig Euborellia caraibea) at night, walking on two contrasted ground types : bare soil and soil partly covered with a stratum of banana plant residues allowing individuals to hide periodically. 3 The tracking of individuals within these ground types was achieved by infrared light, tagging individuals, video treatments and semi-automatic cleaning of trajectories. We tested different procedures to obtain segments with identical durations to quantify speeds and sinuosities. These procedures were characterised by the junction time gap between trajectory fragments, the rediscretisation time of trajectories, and whether or not to use interpolation to fill in missing points in the trajectories. 4 Earwigs exhibited significantly slower and more sinuous movements on soil with banana plant residues than on bare soil. Long time gaps for trajectory junction, extended rediscretisation times and interpolation were complementary means to integrate concealed movements in the trajectories. The highest slowdown in plant residues was detected when the procedure could account for longer periods under the residues. 5 These results suggest that earwigs spent a significant amount of time concealed by the residues. Additionally, the residues strongly decreased the earwigs’ movement. Since the technical solutions presented in this study are inexpensive, easy to set up and replicate, they represent valuable contributions to the emerging field of video monitoring.

Explaining food web dynamics, stability, and functioning depend substantially on understanding of feeding relations within a community. Bulk stable isotope ratios (SIRs) in natural abundance are well-established tools to express direct and indirect feeding relations as continuous variables across time and space. Along with bulk SIRs, the SIRs of individual amino acids (AAs) are now emerging as a promising and complementary method to characterize the flow and transformation of resources across a diversity of organisms, from microbial domains to macroscopic consumers. This significant AA-SIR capacity is based on empirical evidence that a consumer’s SIR, specific to an individual AA, reflects its diet SIR coupled with a certain degree of isotopic differences between the consumer and its diet. However, many empirical ecologists are still unfamiliar with the scope of applicability and the interpretative power of AA-SIR. To fill these knowledge gaps, we here describe a comprehensive approach to both carbon and nitrogen AA-SIR assessment focusing on two key topics: pattern in AA-isotope composition across spatial and temporal scales, and a certain variability of AA-specific isotope differences between the diet and the consumer. On this basis we review the versatile applicability of AA-SIR to improve our understanding of physiological processes as well as food web functioning, allowing us to reconstruct dominant basal dietary sources and trace their trophic transfers at the specimen and community levels. Given the insightful and opportunities of AA-SIR, we suggest future applications for the dual use of carbon and nitrogen AA-SIR to study more realistic food web structures and robust consumer niches, which are often very difficult to explain in nature.

Research on among individual variation in behavior has increased rapidly in recent years. It is intuitively appealing that among individual variation in behavior has ecological consequences and among the most likely to be affected is trophic niche. Bold individuals, with the tendency to be explorative and risk tolerant, can be less likely to alter their foraging behavior across contexts and therefore forage more consistently. Stable isotopes are a useful tool to retrospectively estimate ecological niche and have been found to correlate to foraging behavior in the wild. It is now pressing to extent studies to further examine the ecological or evolutionary relevance of personality. We examined if common behavioral traits were correlated to ecological niche in the wild using a rapid behavioral assay and δ13C and δ15N stable isotopes from fin and muscle reflecting ecological niche for the previous weeks and months. We found that latency to explore, as a proxy for boldness, correlated to values of δ13C with bolder fish having lower δ13C values. Moreover, latency to explore also explained variation in the change in individual stable isotope niche over time. These results highlight the long-term ecological importance of among individual variation in behavior and are among the first to support a correlation of laboratory measures of behavior and ecological niche in the wild.

1. Prairie dogs (Cynomys sp.) are considered keystone species and ecosystem engineers for their grazing and burrowing activities (summarized here as disturbances). As climate changes and its variability increases, the mechanisms underlying organisms’ interactions with their habitat will likely shift. Understanding the mediating role of prairie dog disturbance on vegetation structure, and its interaction with environmental conditions through time, will increase knowledge on the risks and vulnerability of grasslands. 2. Here, we compared how plant taxonomic and functional diversity metrics, along with community-weighted trait means (CWM), respond to prairie dog disturbance across grassland types and seasons in a conservation priority, semiarid grassland of Northeast Mexico. 3. Our findings suggest that functional metrics and CWM analyses responded to interactions between prairie dog disturbance, grassland type and season, whilst species diversity and cover measures were less sensitive to the role of prairie dog disturbance. Contrary to previous studies, we found weak evidence that prairie dog disturbance has a negative effect on vegetation structure, except for minimal effects on C4 and graminoid cover, which depend mainly on season. Grassland type and season explained most of the effects on plant functional and taxonomic diversity as well as CWM traits. Furthermore, we found that leaf area as well as forb and annual cover increased during the wet season, independent of prairie dog disturbance. 4. Our results provide evidence that prairie dog disturbance is less important than grassland type and that environmental effects have a stronger role than grazing and animal disturbances on vegetation. We argue that a focus on disturbance and grazing effects is misleading, and instead attention is needed on the relationships between vegetation and environmental conditions which will be critical to understand semi-arid grassland dynamics in the region. In addition, explicit management strategies to mitigate climate change would need to consider these relationships

The nocturnal activities of predators and prey are influenced by several factors, including physiological adaptations, habitat quality and, we suspect, corresponds to changes in brightness of moonlight according to moon phase. In this study, we used a dataset from 102 camera traps to explore which factors are related with the activity pattern of North China leopards (Panthera pardus japonensis) in Shanxi Tieqiaoshan Provincial Nature Reserve (TPNR), China. We found that nocturnal activities of leopards were irregular during four different lunar phases, and while not strictly lunar philic or lunar phobic, their temporal activity was highest during the brighter moon phases (especially the last quarter) and lower during the new moon phase. On the contrary, roe deer (Capreolus pygargus) exhibited lunar philic activity, while wild boar (Sus scrofa) and Tolai hare (Lepus tolai) were evidently lunar phobic, with high and low temporal activity during the full moon, respectively. In terms of temporal overlap, that there was positive overlap between leopards and their prey species, including roe deer (Capreolus pygargus) and Tolai hare (Lepus tolai), while leopard activity did not dip to the same low level of wild boar during the full moon phase. Generally, our results suggested that besides moonlight risk index (MRI), cloud cover and season have diverse effects on leopard and prey nocturnal activity. Finally, distinct daytime and nighttime habitats were identified, with leopards, wild boar and Tolai hare all using lower elevations at night and higher elevations during the day, while leopards and roe deer were closer to secondary roads during the day than at night.

The neurotransmitter dopamine has been shown to play an important role in modulating behavioural, morphological and life-history responses to food abundance. However, costs of expressing high dopamine levels remain poorly studied and are essential for understanding the evolution of the dopamine system. Negative maternal effects on offspring size from enhanced maternal dopamine levels have previously been documented in Daphnia. Here, we tested whether this translates into fitness costs in terms of lower starvation resistance in offspring. We exposed Daphnia magna mothers to aqueous dopamine (2.3 mg/L or 0 mg/L for the control) at two food levels (ad libitum versus 30% ad libitum) and recorded a range of maternal life history traits. The longevity of their offspring was then quantified in the absence of food. In both control and dopamine treatments, mothers that experienced restricted food ration had lower somatic growth rates and higher age at maturation. Maternal food restriction also resulted in production of larger offspring that had a superior starvation resistance, compared to ad libitum groups. However, although dopamine exposed mothers produced smaller offspring than controls at restricted food ration, these smaller offspring survived longer under starvation. Hence, maternal dopamine exposure provided an improved offspring starvation resistance. We discuss the relative importance of proximate and ultimate causes for why D. magna may not evolve towards higher endogenous dopamine levels despite the fitness benefits this appears to have.

Phytoplankton functional traits can represent particular environmental conditions in complex aquatic ecosystems. Categorizing phytoplankton species into functional groups is challenging and time-consuming, and requires high-level expertise on species autecology. In this study, we introduced an affinity analysis to aid identification of candidate associations of phytoplankton from two datasets comprised of phytoplankton and environmental information. In the Huaihe River Basin with a drainage area of 270,000 km2 in China, samples were collected from 217 selected sites during the low-water period in May 2013; monthly samples were collected during 2006-2011 in a man-made pond, Dishui Lake. Our results indicated that the affinity analysis can be used to define some meaningful functional groups. The identified phytoplankton associations reflect the ecological preferences of phytoplankton in terms of light and nutrients acquisition. Advantages and disadvantages of applying the affinity analysis to identify phytoplankton associations are discussed with perspectives of their utility in ecological assessment.

1. Cattle grazing profoundly affects abiotic and biotic characteristics of ecosystems. While most research has been performed on grasslands, the effect of large managed ungulates on forest ecosystems has largely been neglected. 2. Compared to a baseline semi-natural state, we investigated how long-term cattle grazing of birch forest patches affected the abiotic state and the ecological community (microbes and invertebrates) of the soil subsystem. 3. Grazing strongly modified the soil abiotic environment by increasing phosphorus content, pH and bulk density, while reducing the C:N ratio. The reduced C:N-ratio was strongly associated with a lower microbial biomass, mainly caused by a reduction of fungal biomass. This was linked to a decrease in fungivorous nematode abundance and the nematode channel index, indicating a relative uplift in the importance of the bacterial energy-channel in the nematode assemblages. 4. Cattle grazing highly modified invertebrate community composition producing distinct assemblages from the semi-natural situation. Richness and abundance of microarthropods was consistently reduced by grazing (excepting collembolan richness) and grazing-associated changes in soil pH, Olsen P and reduced soil pore volume (bulk density) limiting niche space and refuge from physical disturbance. Anecic earthworm species predominated in grazed patches, but were absent from ungrazed forest, and may benefit from manure inputs, while their deep vertical burrowing behaviour protects them from physical disturbance. 5. Perturbation of birch forest habitat by long-term ungulate grazing profoundly modified soil biodiversity, either directly through increased physical disturbance and manure input or indirectly by modifying soil abiotic conditions. Comparative analyses revealed the ecosystem engineering potential of large ungulate grazers in forest systems through major shifts in the composition and structure of microbial and invertebrate assemblages, including the potential for reduced energy flow through the fungal decomposition pathway. The precise consequences for trophic interactions and biodiversity-ecosystem function relationships remains to be established, however.

The Species-Sorting concept, one of the models developed to explain patterns in metacommunity structure, suggests that relationships between biological communities and environmental conditions is the basic means of the species selection processes. A second concept is Neutral Theory, and the idea of neutral dynamics underpinning metacommunity structure, cannot be overlooked. The third mechanism is the Mass-Effect concept, that focuses on the interaction between environmental condition and neutral effects. In the present study, we partitioned fish communities in streams between niche and neutral theory concepts, identifying the best representation of metacommunity structure, and assessed if linear and hydrographic distance were equivalent in the representation of neutral processes. The result points to the importance of species sorting mechanisms in structuring fish communities with neutral processes best represented by the linear distances. These results are important for the fish fauna conservation leading to three considerations: (i) the variation of the landscape and habitat is important for the stream fish, (ii) the natural barriers are an important landscape component to be considered, and (iii) the artificial barriers (dams and impoundments) need to be planned taking in account the catchment basin as the landscape unit.

The relationships among species diversity, functional diversity, functional redundancy, and community stability are central to community and ecosystem ecology. This paper examines plant communities at different stages of vegetation restoration in the Guizhou karst plateau to study the relationship among functional diversity, functional redundancy, and stability of plant communities. The most important results include the following. (1) Species diversity (SD), functional redundancy (FR), and stability (STB) gradually increased with restoration, and there were significant differences among the different stages; functional diversity (FD) increased at first and then decreased, and reached the highest level at the tree irrigation stage. (2) Plant height (PLH) and specific leaf area (SLA) were functional traits that affected the diversity and stability of the plant community, and PLH was positively correlated with plant community diversity and stability, while SLA was negatively correlated with plant community diversity and stability. (3) During the community recovery, FD and FR interacted to maintain stability. In the early and late stages of recovery, the effect of functional redundancy on stability was greater than that of functional diversity, but it was the opposite in the middle stages. (4) The tree irrigation stage is the likely point at which the species diversity of plant communities in karst areas reached saturation, and the growth rate of functional redundancy after species diversity saturation was greater than that before saturation.

Indiscriminate fire is rampant throughout subtropical South and Southeast Asian grasslands. However, very little is known about the role of fire and pyric herbivory on the functioning of highly productive subtropical monsoon grasslands lying within Cwa-climatic region. We collected grass samples from 60 m x 60 m plots and determined vegetation physical and chemical properties at regular 30-day intervals from April to July 2020, starting from 30 days after fire to assess post-fire regrowth forage quality. We counted pellet groups for the same four months from 2 m x 2 m quadrats that were permanently marked with pegs along the diagonal of each 60 m x 60 m plot to estimate grazing intensity to the progression of post-fire regrowth. We observed strong and significant reductions in crude protein (mean value 9.1 to 4.1 [55% decrease]) and phosphorus (mean value 0.2 to 0.11 [45% decrease]) in forage collected during different time intervals i.e., from 30 days to 120 days after fire. Mesofaunal deer utilised the burned areas extensively for a short period, i.e., up to two months after fire when the burned areas contained short grasses with a higher level of crude protein and phosphorus. Grazing intensity of chital (Axis axis) to post-fire regrowth differed significantly over time since fire, with higher intensity of use at 30 days after fire. Grazing intensity of swamp deer (Rucervus duvaucelii) did not differ significantly until 90 days after fire, however, decreased significantly after 90 days since fire. Large-scale indiscriminate single event fires thus may not fulfil nutritional requirements of all species in mesofaunal deer community in these subtropical monsoon grasslands. We recommend for a spatio-temporal manipulation of fire to reinforce grazing feedback and to yield for the longest possible period a reasonably good food supply for the conservation of mesofaunal deer.

Molluscs are an important component of the mangrove ecosystem, and the vertical distributions of molluscan species in this ecosystem are primarily dictated by tidal inundation. Thus, sea-level rise (SLR) may have profound effects on mangrove mollusc communities. Here, we used two dynamic empirical models based on measurements of surface elevation change, sediment accretion and zonation patterns of molluscs to predict changes in molluscan spatial distributions in response to different sea-level rise rates in the mangrove forests of Zhenzhu Bay (Guangxi, China). The change in surface elevation was 4.76–9.61 mm a−1 during the study period (2016–2020), and the magnitude of surface-elevation change decreased exponentially as original surface elevation increased. Based on our model results, we predicted that mangrove molluscs might successfully adapt to a low rate of SLR (marker-horizon model: 2–4.57 mm a−1; plate model: 2–5.20 mm a−1) by 2100, with molluscs moving seaward and those in the lower intertidal zones expanding into newly available zones. However, as SLR rate increased (marker-horizon model: 4.57–8.14 mm a−1; plate model: 5.20–6.88 mm a−1), our models predicted that surface elevations would decrease beginning in the high intertidal zones and gradually spreading to the low intertidal zones. Finally, at high rates of SLR (marker-horizon model: 8.14–16.00 mm a−1; plate model: 6.88–16.00 mm a−1), surface elevations were predicted to decrease across the elevation gradient, with molluscs moving landward and species in higher intertidal zones would be blocked by landward barriers. Tidal inundation and the consequent increase in interspecific competition and predation pressure were predicted to threaten the survival of many molluscan groups in higher intertidal zones, especially species at the landward edge of the mangroves. Thus, future efforts to conserve mangrove floral and faunal diversity should prioritize species restricted to landward mangrove areas.

In this study, the plant communities at five succession stages (herbage, herbage-shrub, shrub, tree-shrub, and tree) in the Zhenning Karst Plateau area of Guizhou were examined. The changes of plant functional characteristics in different succession stages were analyzed, as was the relationship between functional traits and environmental factors. The main results include the following. (1) During the succes-sion process, plant height, leaf dry matter mass, leaf area, leaf nitrogen content, and leaf phosphorus content gradually increased, whereas leaf thickness and specific leaf area decreased, and leaf C:P ratio and leaf N:P ratios did not change significantly. (2) Soil organic matter, soil total nitrogen, soil total phosphorus, soil C:N, soil C:P, and soil C:K increased at first and then decreased, reaching a peak at the tree-shrub stage. Soil total potassium fluctuated and soil bulk density gradually decreased and reached the lowest value at the tree-shrub stage. (3) Redundancy analysis (RDA) showed that the plant community shifted from a nutri-ent-poor soil environment to a nutrient-rich environment. Soil total phosphorus, soil C:K, soil organic mat-ter, soil C:N, and soil bulk density were the key environmental factors affecting the change of functional traits. (4) Structural equation modeling suggests that that specific leaf area and leaf nitrogen content had more sensitive responses to soil nutrient resources and environmental factors, respectively.