The small brown planthopper (SBPH), Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) is a most destructive rice pest which has caused serious economic losses in China. To effectively manage this pest, we investigated genomic polymorphism, evaluated genetic divergence and populations genetic structure of SBPH at 31 sampling sites in China using a population genomics approach. In this study, we generated over 2,813,221,369 high-quality paired-end reads (413,689.55 Mb) across 306 individuals derived from double-digest restriction site-associated DNA sequencing (ddRAD-seq), and 1925 reliable single nucleotides (SNPs) were detected with an average sequencing depth of 13.99×. Overall, low levels of genetic diversity and strong genetic differentiation among all of populations were obtained (Global FST = 0.261). Neighbour-joining dendrograms, Bayesian clustering methods, discriminant analysis of principal components (DAPC) and principal component analysis (PCA) revealed three genetically distinct groups: Southwestern group, Northern group and Eastern group. Furthermore, we also observed a high degree of admixture, widespread hybridization and gene flow among populations of Northern China. A Mantel test indicated a pattern of isolation-by-distance throughout China (r = 0.211, P = 0.031). Neutrality test indicated SBPH has experienced a recent population expansion. Accordingly, our results provide new insights into the genetics of SBPH and thus contribute to develop effective management strategies for this pest.

1. Some small mammals exhibit Dehnel’s phenomenon, a drastic decline in body mass, braincase and brain size from summer to winter, followed by a regrowth in spring. This is accompanied by a reorganization of the brain and changes in other organs. The evolutionary link between these changes and seasonality remains unclear, although the magnitude of change varies between locations as the phenomenon is thought to lead to energy savings during winter. 2. Here we explored geographic variation of the intensity of Dehnel’s phenomenon in Sorex araneus. We compiled the literature on seasonal changes in braincase size, brain and body mass, supplemented by our own data from Poland, Germany and Czech Republic. 3. We analysed the effect of geographic and climate variables on the magnitude of change and patterns of brain reorganization. 4. From summer to winter the braincase height decreased by 13%, followed by 10% regrowth in spring. For body mass the changes were -21%/+82%, respectively. Changes increased along the north-east axis. Several climate variables were correlated with these transformations, confirming a link of the magnitude of the changes with environmental conditions. This relationship differed for the brain mass decline vs. regrowth, suggesting that they may have evolved under different selective pressures. 5. We found no geographic trends explaining variability in the brain mass changes although they were similar (-21%/+10%) to those of the braincase size. Underlying patterns of change in brain organisation in North-Eastern Poland were almost identical to the pattern observed in Southern Germany. This indicates that local habitat characteristics may play a more important role in determining brain structure than broad scale geographic conditions. 6. We discuss the techniques and criteria used for studying this phenomenon, as well as its potential presence in other taxa and the importance of distinguishing it from other kinds of seasonal variation.

The forest people around the world through their indigenous knowledge contribute to the sustainable management of forests. This article argues that the Sheka people in southwestern Ethiopia by their ecological knowledge, values, and spiritual use could manage the Ororo tree (Ekebergia capensis). The Ororo tree (Ekebergia capensis) is one of the most important endemic tree species in the Sheka zone southwestern Ethiopia and, at the same time, one of the most endangered species. Data collected on the indigenous ecological knowledge of the Sheka people and how the Ororo tree could be managed and conserved through the DEDO culture documented and the spiritual connection between the Ororo trees and the Sheka people traditional belief system measured. The findings revealed that through their traditional forestrelated knowledge, the Sheka people conserve and manage a single larger tree called Ororo. The Ororo tree is a special type of tree that has cultural and spiritual attachments that are presently non-existent. This unique forest conservation practice has been referred to as the DEDO culture. The culture of DEDO comes up with worshiping around the Ororo tree. Thus, the culture of DEDO played an important role in maintaining the conservation of the DEDO sacred tree (Ororo) and biodiversity therein. Over time, the DEDO sacred tree (Ororo) conservation culture has been decline, and various factors have contributed to the decline of this useful ecological knowledge.

ABSTRACT Aim Invasive species are one of the main causes of biodiversity loss world-wide. As introduced populations increase in abundance and geographical range, so does the potential for negative impacts on native communities. As such, there is a need to better understand the processes driving range expansion as species become established in recipient landscapes. We investigated the potential for population growth and range expansion of introduced populations of a non-native lizard (Podarcis muralis), considering multi-scale factors influencing growth and spatial spread. Location England, UK Methods We collated records of P. muralis presence through field surveys and a citizen science campaign. We used presence-only models to predict climate suitability at a national scale (5km resolution), and fine-scale habitat suitability at the local scale (2m resolution). We then integrated local models into an individual-based modelling platform to simulate population dynamics and forecast range expansion for 10 populations in heterogeneous landscapes. Results National-scale models indicated climate suitability restricted to the southern parts of the UK, limited by a latitudinal cline in overwintering conditions. Patterns of population growth and range expansion were related to differences in local landscape configuration and heterogeneity. Growth curves suggest populations could be in the early stages of exponential growth. However, annual rates of range expansion are predicted to be low (5-16 m). Conclusions We conclude that extensive nationwide range expansion through secondary introduction is likely to be restricted by currently unsuitable climate beyond southern regions of the UK. However, exponential growth of local populations in habitats providing transport pathways is likely to increase opportunities for regional expansion. The broad habitat niche of P. muralis, coupled with configuration of habitat patches in the landscape, allows populations to increase locally with minimal dispersal.

A document by Qing Xia, written on Authorea.

1. Fire and frost represent two major hurdles for the persistence of trees in open grassy biomes and have both been proposed as drivers of grassland-forest boundaries in Africa. 2. We assess the response of young tree seedlings, which represent a vulnerable stage in tree recruitment, to traumatic fire and frost disturbances. 3. In a greenhouse experiment, we investigated how seedling traits predicted survival and resprouting ability in response to fire vs frost; we characterised survival strategies of seedlings in response to the two disturbances, and we documented how the architecture of surviving seedlings is affected by fire vs frost injury. 4. Survival rates were similar under both treatments. However, different species displayed different levels of sensitivity to fire and frost. Seedling survival was higher for older seedlings and seedlings with more basal leaves. Survivors of a fire event lost more biomass than the survivors of a frost event. However, the architecture of recovered fire and frost treated seedlings were mostly similar. Seedlings that recovered from fire and frost treatments were often shorter than those that had not been exposed to any disturbance, with multiple thin branches, which may increase vulnerability to the next frost or fire event. 5. Synthesis. Fire caused more severe aboveground damage compared to frost, suggesting that trees in these open grassland systems may be subjected to a seedling release bottleneck maintained by fire. However, the woody species composition will almost certainly be influenced by phenomena that affect the timing and frequency of seedling exposure to damage, as mortality was found to be dependent on seedling age. Therefore, changes in fire regime and climate (esp. changes that bring about less frost and reduced fire intensity and frequency) are likely to result in changes in the composition and the structure of the woody components of these systems.

Population genomics is a useful tool in the integrated pest management toolbox for elucidating population dynamics, demography, and histories of invasion. However, next-generation sequencing approaches can be hampered by low DNA input from small organisms, such as insect pests. Here, we use a restriction-site associated DNA sequencing approach combined with whole-genome amplification to assess genomic population structure of a newly described pest of canola, the diminutive canola flower midge, Contarinia brassicola. We find that whole-genome amplification prior to library preparation caused a reduction in the overall number of loci sequenced and an increase in overall sequencing depth but had no discernable impact on genotyping consistency for population genetic analysis. Clustering analyses recovered little geographic structure across the main canola production region, but differentiated several geographically disparate populations at edges of the agricultural zone. Given a lack of alternative hypotheses for this pattern, we suggest these data support alternative hosts for this species and thus our canola-centric view of this midge as a pest has limited our understanding of its biology. These results speak to the need for increased surveying effort across multiple habitats and other potential hosts within Brassicaceae, to elucidate both our ecological and evolutionary knowledge of this species as well as potential management implications.

Most herbivorous insects are diet specialists in spite of the apparent advantages of being a generalist. This conundrum might be explained by fitness trade-offs on alternative host plants, yet evidence of such trade-offs has been elusive. Another hypothesis is that specialization is non-adaptive, evolving through neutral population genetic processes and within the bounds of historical constraints. Here we report on a striking lack of evidence for the adaptiveness of specificity in tropical canopy communities of armored scale insects. We show that specialists abound and that host-use is phylogenetically conservative, but in comparison to generalists, specialists occur on fewer of their potential hosts, and are no more abundant where they do occur. Of course local communities might not reflect regional diversity patterns. But based on our samples, comprising hundreds of species of hosts and armored scale insects at two widely separated sites, host-use specialists do not appear to outperform generalists.

Foraging decisions are essential for survival, thus investigation of food preferences is a major goal in behavioral ecology. Cafeteria trials, in which multiple options are displayed to foragers simultaneously, can quantify these preferences. However, statistical analyses of these data are problematic. The aim of this research is to determine the efficacy of using Shannon Diversity (Hs) and Evenness (J) to quantify diet preferences and apply this approach to field data collected in a model system. Shannon Diversity (Hs) provides a single value to represent a forager’s diet, based on proportions of each food type offered. Shannon Evenness (J’) assesses the relative quantity of each food type consumed, and is an intuitive way to address foraging preferences. Null models inspected how values of Hs and J’ change with diet breadth. This approach was tested for a cafeteria trial of two common chipmunks [Eastern (Tamias striatus) and Least (Neotamias minimus)] with five different seed types [Red (Acer rubrum) and Sugar (A. saccharum) Maple, Balsam Fir (Abies balsamea), Pin Cherry (Prunus pensylvanica), and Beaked Hazelnut (Corylus cornuta)]. Hypothesis tests determined if observed diets were statistically different from those predicted based on equal preferences. Values of Hs increased with diet breadth; although mean J’ was unaffected by diet breadth, variability increased. Chipmunks displayed significant seed preferences: Tamias preferred Sugar Maple whereas Neotamias preferred Red Maple. Moreover, each species avoided the seed type preferred by the other chipmunk. Null models indicate that Hs accurately estimates real changes in diet breadth. The fact that J’ did not significantly change with increasing diet breadth also supports the utility of this approach to determine non-random diet preferences. Use of diversity indices to quantify feeding choices can be extended to other contexts (e.g., comparison of suites of foragers, and altering feeding context by changing amounts of each resource offered).

In recent decades, alpine grassland has been serimously degraded across the Qinghai Tibetan Plateau (QTP), although grazing exclusion has been widely adopted to restore degraded QTP grassland. It remains unknown whether this management approach is effective for all degraded alpine grasslands. In this study, plots with three grazing management treatments (free grazing, FG; reduced grazing, RG; grazing exclusion, GE) and four degradation stages (non-degradation, ND; light degradation, LD; moderate degradation, MD; heavy degradation, HD) were compared. Our results showed that the total aboveground biomass (AGB) and species richness (SR) were reduced while total belowground biomass (BGB) increased with increasing degradation, and the responses of SR, AGB and BGB to grazing management varied with the degree of degradation. The total AGB in the LD, MD and HD stages reduced significantly after 6 years under RG and GE, but there was no significant change of AGB in the ND stage. Meanwhile, SR reduced significantly after 6 years under RG and GE across all degradation stages except for HD. Furthermore, the responses of plant functional groups to grazing management varied. After 6 years under RG and GE, the Gramineae AGB increased significantly across all degradation levels; that of the sedges decreased (except in the MD stage); and that of the forbs increased significantly in LD and HD but decreased significantly in ND. Our result suggested that the light degradation grassland can be restored by reducing grazing, and moderate degradation and heavy degradation grassland can restored by grazing exclusion.

The use of museum specimens held in natural history repositories for population and conservation genetic research is increasing in tandem with the use of next generation sequencing technologies. Short Tandem Repeats (STRs), or microsatellite loci, are commonly used genetic markers in population and conservation genetic studies. However, they traditionally suffered from a host of issues: fragment size homology, high costs, and low throughput as a result of capillary electrophoresis genotyping and difficulty in reproducibility across laboratories. Next generation sequencing technologies can address these problems, but the incorporation of DNA derived from museum specimens suffers from significant fragmentation and contamination with exogenous DNA. Combatting these issues requires extra measures of stringency in the lab and during data analysis, yet there have not been any studies evaluating microsatellite allelic dropout from museum specimen extracted DNA. In this study, we explore a high throughput sequencing method to evaluate the amount of variation found within museum specimen DNA extracts for previously characterized microsatellites across PCR replicates. We found it useful to classify samples based on quality after replicated PCRs, which determined the rate by which genotypes were accurately recovered. We also found that longer microsatellites performed worse in all museum specimens, so when designing a study invoking museum specimens, short markers (under 250 bp) should be preferentially selected. Allelic dropout rates across loci were dependent on sample quality. The high quality museum specimens performed as well, and recovered nearly as high quality metrics as our tissue sample. Mitochondrial DNA sequences were not predictive of nuclear DNA presence, as all samples recovered cytochrome b fragments yet many lacked microsatellite genotypes, particularly in samples deemed low quality. Based on our results, we have provided a set of best practices for screening, quality assurance, and incorporation of reliable genotypes from museum specimens.

1. Deep roots have long been thought to allow trees to coexist with shallow-rooted grasses. Due to the difficulties of working belowground, data demonstrating water uptake and niche partitioning are uncommon. 2. We describe tree and grass root distributions using a depth-specific tracer experiment in a subtropical savanna, Kruger National Park, South Africa. The depth-specific tracer experiment was conducted three times during each of two growing seasons. These point-in-time measurements (i.e., tracer-defined root distributions) were then used in a soil water flow model to estimate continuous water uptake by depth and plant growth form (trees and grasses) across the two growing seasons. 3. Most active tree and grass roots were in shallow soils: the mean depth of water uptake was 22 cm for trees and 17 cm for grasses. However, slightly deeper rooting distributions provided trees with 5% more soil water than the grasses in a drier precipitation year, but 13% less water in a wet year. Small differences in rooting distributions also provided both trees and grasses with depths and times at which each rooting distributions (tree or grass) could extract more soil water than the other (i.e., unique hydrological niches of 4 to 13 mm water). 4. The effect of rooting distributions has long been inferred. By quantifying the depth and timing of water uptake, this research demonstrated that even though rooting distributions appeared similar, they provided trees and grasses with more total water, access to a unique hydrologic niche, or both. This approach demonstrated how even small differences in rooting distributions can provide plants with resource niches that can contribute to species coexistence.

The contribution of wild insects to crop pollination is becoming increasingly important as global demand for crops dependent on animal pollination increases. If wild insect populations are to persist in agricultural landscapes, there must be sufficient floral resources (FR) over time and space. The temporal, within-season component of FR availability has rarely been investigated, despite growing recognition of its likely importance for pollinator populations. Here, we examined the visitation rates of common bee genera and the spatiotemporal availability of FR in agroecosystems over one season to determine whether local bee activity was limited by the abundance of landscape FR, and if so, whether it was limited by the present or past abundance of landscape FR. Visitation rates and landscape FR were measured in 27 agricultural sites in Ontario and Québec, Canada, across four time periods and three spatial scales. Landscape FR at varying spatial scales predicted visits for the seven most commonly observed bee genera. Bombus visitation rates were higher in landscapes that had greater cumulative seasonal abundance of FR, suggesting the importance of early-season FR for this taxon. Visits from Halictus and Lasioglossum were higher in landscapes that provided either a stable or increasing amount of FR over the season and were lower in landscapes that experienced a decrease in FR over the course of a season. Andrena, Augochlorella, Megachile, and Peponapis visits were not measurably influenced by FR in previous months but were lower in landscapes that had a higher present abundance of FR, perhaps reflecting pollinator movement or dilution. Our research provides insight into how seasonal fluctuations in floral resources affect bee activity, and by examining each bee genus separately, we could observe how differences in foraging periods, foraging ranges, and the number of broods per season influence how bee taxa respond to food availability within agroecosystems.

1. Quantitative PCR (qPCR) has been commonly used to measure gene expression in a number of research contexts, but the measured RNA concentrations do not always represent the concentrations of active proteins which they encode. This can be due to transcriptional regulation or post-translational modifications, or localisation of immune environments, as can occur during infection. However, in studies using free-living non-model species, such as in ecoimmunological research, qPCR may be the only available option to measure a parameter of interest, and so understanding the quantitative link between gene expression and associated effector protein levels is vital. 2. Here we use qPCR to measure concentrations of RNA from mesenteric lymph node (MLN) and spleen tissue, and multiplex ELISA of blood serum to measure circulating cytokine concentrations in a wild population of a model species, Mus musculus domesticus. 3. Few significant correlations were found between gene expression levels and circulating cytokines of the same immune genes or proteins, or related functional groups. Where significant correlations were observed, these were most frequently within the measured tissue (i.e. the expression levels of genes measured from spleen tissue were more likely to correlate with each other rather than with genes measured from MLN tissue, or with cytokine concentrations measured from blood). 4. Potential reasons for discrepancies between measures, including differences in decay rates and transcriptional regulation networks are discussed. We highlight the relative usefulness of different measures under different research questions, and consider what might be inferred from immune assays.

High-throughput sequencing technology was used to analyse the species diversity, richness and dynamics of fungal communities in healthy and infected walnut leaves. The dominant phyla included Ascomycota, Basidiomycota, and Glomeromycota; the dominant classes were Tremellomycetes, Dothideomycetes, and Leotiomycetes; the dominant orders were Tremelellas, Capnodiales, and Erysiphales; the dominant families were Bulleribasidiaceae, Mycosphaerellaceae, and Erysiphaceae; the dominant genera were Vishniacozyma, Cercospora, and Ramularia; and the dominant species were Vishniacozyma heimaeyensis, Cercospora asparagi, and Cladosporium chasmanthicola. The results of this study also provided a new understanding of the succession of the walnut phyllosphere fungal community, filling a void in the knowledge of the microbial diversity associated with walnut leaf spot disease. At the same time, these results provide a scientific basis for early intervention and micro-ecological regulation of walnut phyllosphere fungal communities to prevent and control leaf spot or anthracnose.

A research study on morphometrics of Kalophrynus palmatissimus (known as Lowland Grainy Frog) at Ayer Hitam Forest Reserve (AHFR), Selangor and Pasoh Forest Reserve (PFR), Negeri Sembilan was carried out from 12 November 2016 to 13 September 2017. The study was conducted to examine data on the morphometric traits of K. palmatissimus at the two forest reserves. 15 morphometric traits of K. palmatissimus were taken by using vernier calipers. Frog surveys were done by using 15 and 18 nocturnal 400 m transect lines at AHFR and PFR, respectively. In addition, five climatic data were recorded. The results showed that most of the morphometric traits in AHFR (n = 34) and PFR (n = 31) were positively correlated within each other. General Linear Model (GLM) analysis, showed that snout-vent length (SVL) influenced most morphometric traits, except for hand length. Later, it was found that the snout-vent length of K. palmatissimus in AHFR were slightly larger than PFR. From PCA analysis, morphometric traits were grouped into two components for AHFR and PFR, respectively. In AHFR, head length, eye diameter, head width, internarial distance, interorbital distance, forearm length, tibia length, foot length, and thigh length were strongly correlated while snout length and eye-nostril distance were strongly correlated. In PFR, eye diameter, head width, internarial distance, interorbital distance, foot length and thigh length were strongly correlated, while snout length and eye-nostril distance were strongly correlated; hence, suggesting that all morphometric traits grow simultaneously in K. palmatissimus with eye-nostril distance (EN), and snout length (SL) were closely growing simultaneously at AHFR and PFR. To conclude, the data collections showed the 15 different morphometric traits of K. palmatisssimus between AHFR and PFR with K. palmatissimus at AHFR were slightly larger than at PFR. Key words: Kalophrynus palmatissimus, forest reserve, morphometrics, climatic factors, transect lines

The nature of matter and energy exchange of an ecological process defines the applicability of the thermodynamic functions for describing an ecosystem. A plant community is an open system consisting of living species as material components. Following the basic laws of thermodynamics, the enthalpy H stored in biomass form of a plant community will be related to its total equivalent biomass quantity CT, the weighted average standard chemical potential μ0, Gibbs free energy G, entropy S and temperature T by H = G + TS = CTμ0. Using h, f and s to denote H/(RT), G/(RT) and S/R (R denoting the gas constant), respectively, the conventional function can be transformed to h = f + s = CTμ0/(RT). The relation sm/CT = SIm = ln(N) derived from the maximal discrete entropy theorem shows that sm (the maximum s) and SIm (the maximum information entropy) will increase with increase in the total number of species N, suggesting that N has an upper limit Nm subject to regional species resource. As an upper limt of SI and s/CT, ln(N) is applied as a biodiversity index. As an upper limt of ln(N), ln(Nm) can thus be regarded as a biodiversity potential index as it takes into account the available number of species distributed in the surrounding areas of the plant community, showing the potential limit for further increase in its biodiversity. The difference between ln(Nm) and ln(N) dtermines the distribution of H as G and TS, indicating that the internal energy distribution of an acosystem is a function of its productivity and biodiversity. The potential trends of increasing N towards Nm and increasing s towards sm suggest that an ecosystem can possess natural trends towards increase in both its species richness and evenness.

Geographical gradients in species diversity have long fascinated biogeographers and ecologists. However, the extent and generality of the positive/negative effects of the important factors governing functional diversity (FD) patterns are still debated, especially for the freshwater domain. We examined lake productivity and functional richness (FRic) of waterbirds sampled from 35 lakes and reservoirs in northern China with a geographic coverage of over 5 million km2. We used structural equation modelling (SEM) to explore the causal relationships between geographic position, climate, lake productivity and waterbirds FRic. We found unambiguous altitudinal and longitudinal gradients in lake productivity and waterbirds FD, which were strongly mediated by local environmental factors. Specifically, we found 1) lake productivity increased northeast but decreased with altitude, and the observed gradients were driven by climate and nutrient availability, with 93% of variation explained in the individual SEM; 2) waterbirds FD showed similar geographic and elevational gradients.; the environmental factors which had direct and/or indirect effects on these geographic and elevational gradients included climate, lake productivity and morphology, which collectively explained more than 56% of the variation in waterbirds FD; and 3) a significant (P = 0.029) causality between lake productivity and waterbirds FD was confirmed. Nevertheless, the causality link was relatively weak in comparison with climate and lake area (standardized path coefficient was 0.65, 0.21, and 0.17 for climate, area, and productivity, respectively). Through articulating the dominant causality paths, our results could contribute to the mechanistic explanations underlying the observed broad–scale biodiversity gradients.

The experimental data used for testing the applicability of the thermodynamic equations presented in the theoretical section were obtained from an ecological restoration project implemented at a manganese tailing site. Restoration of the plant community was shown to be an irreversible process characterized by spontaneous increases in its total biomass CT and total number of plant species N associated with increases in its enthalpy H, Gibbs free energy G and entropy S. Species enrichment was the cause for the decease in mass ratio xi (biomass of a species Ci divided by CT) and biomass growth potential μi (the partial derivative of Gi with respect to Ci). The increase in s/CT (s denoting the ratio of S to gas constant R) associated with decrease in f/CT (f denoting the ratio of G to RT) with increasing N confirmed that the restored plant community possessed natural trends towards increase in its species richness and evenness. The observed trends gave support to use of the thermodynamic functions for describing the productivity-biodiversity relationship. The present analysis did not fully prove the use of the Shannon form of information entropy as a biodiversity index for the investigated plant communities. Because of the presence of significant differences in individuals among species, the biodiversity of the plant community could not be uniquely determined by its individual numbers. In comparison, the entropy factor s was shown to be a suitable biodiversity index. The fact that N is the key factor that determines the changes in s/CT and f/CT makes △N > 0 a useful index for determining the direction of spontaneous changes for all open systems with continuous input of matter and energy. As a measure of disorder, s can be generally applied as a diversity index for all systems involving transformations of matter and energy.

A universal attribute of species is that their distributions are limited by numerous factors that may be difficult to quantify. Furthermore, climate change-induced range shifts have been reported in many taxa, and understanding the implications of these shifts remains a priority and a challenge. One approach is to employ species distribution models which correlates species presence data with a set of predictor variables. Here, we use MAXENT to predict current suitable habitat and to project future distributions of two closely related Phymata species in light of anthropogenic climate change. Using species occurrence data from museum databases and environmental data from WorldClim, we identified environmental variables maintaining the distribution of Phymata americana and Phymata pennsylvanica, and created binary suitability maps of current distributions for both species on ArcMap. We then predicted future distributions using the same environmental variables under different Representative Concentration Pathways (RCP), created binary suitability maps for future distributions, and calculated the degree of overlap between the two species. We found that the strongest predictor to P. americana ranges was precipitation seasonality, while precipitation of the driest quarter and mean temperature of the coldest quarter were strong predictors of P. pennsylvanica ranges. Future ranges for P. americana are predicted to increase northwestward and southward at higher CO2 concentrations. Suitable ranges for P. pennsylvanica are initially predicted to increase, but eventually decrease with slight fluctuations around range edges. There is an increase in overlapping ranges in all future predictions. These differences in optima provide evidence for different environmental requirements for P. americana and P. pennsylvanica, accounting for their distinct ranges. Because these species are ecologically similar and can hybridize, climate change has potentially important eco-evolutionary ramifications. Overall our results are consistent with effects of climate change that is highly variable across species, geographic regions and over time.

Accurately estimating abundance is a critical component of monitoring and recovery of rare and elusive species. Spatial capture-recapture (SCR) models are an increasingly popular method for robust estimation of ecological parameters. We provide a maximum likelihood analytical framework to assess results from empirical studies to inform SCR sampling design, using both simulated and empirical data from non-invasive genetic sampling of seven boreal caribou populations (Rangifer tarandus caribou) which varied in range size and estimated population density. We use simulated population data with varying levels of clustered distributions to quantify the impact of non-independence of detections on density estimates, and empirical datasets to explore the influence of varied sampling intensity on the relative bias and precision of density estimates. Simulations revealed that clustered distributions of detections did not significantly impact relative bias or precision of density estimates. The empirical genotyping success rate was 95.1%. Empirical results indicated that reduced sampling intensity had a greater impact on density estimates in smaller ranges. The number of captures and spatial recaptures were strongly correlated with precision, but not relative bias. The best sampling designs did not differ with estimated population density but differed between large and small ranges. We provide an efficient framework implemented in R to estimate the detection parameters required when designing SCR studies. The framework can be used when designing a monitoring program to minimize effort and cost while maximizing effectiveness, which is critical for informing wildlife management and conservation.

Species dispersal patterns and population genetic structure can be influenced by large geographical features and habitat fragmentation. The Qinling Mountains are a major east-west mountain range and they are also the northernmost habitat of wild Cymbidium faberi in China. However, the impact of the Qinling Mountains and habitat fragmentation in the areas on genetic variation of C. faberi at population level is still poorly understood. Here, genetic analysis of C. faberi in the Qingling Mountains was conducted based on two chloroplast DNA sequences of 271 samples in 15 locations. Hierarchical analyses of molecular variance (AMOVA) and mantel test indicated that most of the genetic variance was within populations, genetic distance between populations was correlated with the geographical distance but not strong (mantel r = 0.505, P = 0.011). Spatial analysis of molecular variance (SAMOVA) indicated that the FCT reached the maximum value at K = 2 and then decreased, which supported a two-group genetic structure. Furthermore, the Extended Bayesian Skyline Plot revealed that the estimates of effective population size of C. faberi were under demographic equilibrium in the past but an apparent decline going from approximately 1 Ma towards the present. Moreover, we found that the genetic diversity of C. faberi in fragmented landscape was lower compared to continuous ones. Therefore, we concluded that the habitat fragmentation has restricted the gene flow of C. faberi by disrupting seed dispersal. Our findings may provide helpful references for understanding how humans shape the genetic structure and the importance of conserving wild orchids.

Aims How plant-plant interactions vary with the changes of biotic and abiotic factors has debated for a long time among ecologists. The aim of this study was to explore how different neighbors influenced the responses of the intensity and importance of competition on Stipa grandis and S. krylovii to the change of soil nutrition condition. Methods The seedlings of the target species, S. grandis and S. krylovii, were grow alone and in two-species mixtures with different neighbors under two soil nutrition treatments. For each target species, we measured the biomass, root: shoot ratio, intensity and importance of competition and nutrition-addition effect. Important Findings We founded that the competition responses were mediated by the identities of neighbors and target species. (1) When in mixture with Leymus chinensis, both intensity and importance of competition negatively increased with the increase of soil nutrition. The competition importance was significantly negative on S. grandis under both soil nutrition treatments and on S. krylovii under the high soil nutrition treatment, supporting Grime’s theory. (2) When in S. grandis – S. krylovii mixture system, the competition inhibition decreased while competition importance showed no significant effects on both target species with the increase of soil nutrition, indicating competitive reduction. (3) When in mixture with Agropyron cristatum, the competition intensity significantly influenced by the interaction between target species and soil nutrition, suggesting competitive change along the soil nutrition gradient. The competition importance was significantly negative on S. grandis under the low soil nutrition treatment and on S. krylovii under the high soil nutrition treatment. Ultimately, our results demonstrate that the identities of both target and neighbor species influenced the responses of intensity and importance of competition to the change of soil nutrition condition. Several mechanisms potentially contributed to these different competition effects on different target species.

Inherent in climate change experiments is the assumption that researchers seek to understand the impacts of contemporary climate change and not the impacts of changes in the abiotic environment that are not predicted to occur. In general, climate warming is expected to be asymmetrical, with a mean increase in temperature that is driven more by warming at night rather than during the day. However, climate warming experiments tend to disproportionately increase daytime temperatures. If day and night warming have different effects on ecosystems, the mismatch in timing may produce misleading inference about the effects of climate change. To better understand how the timing of warming affects species and their interactions, we examined a food chain of lady beetles, aphids and host plants within environmental chambers programmed to simulate four w treatments (ambient, constant warming, day warming, and night warming). Our results show that the timing of warming influences predators and their interactions with prey in several ways. In plant-only treatments, all warming treatments increased plant above-ground biomass. When aphids were added, the positive direct effect of warming on plants disappeared, and night-warming indirectly reduced plant biomass more than the day- and constant-warming treatments. Although our feeding trial experiments found that lady beetles in day-warming treatments consumed the most aphids in a 24 hour period, predators generated a trophic cascade in only the night warming treatment. Our results contributes to mounting evidence predators can mediate the effects of climate warming and that these predators are affected by day and night warming differently.