Primula, well known for its heterostyly, is the largest genus in the family Primulaceae with more than 500 species. The considerable species number has introduced a huge challenge for taxonomy. Although several phylogenetic constructions have been carried out thoroughly, the relationships between Primula species were remained incompletely understood, especially for the relationship among sections within Chinese species. P. wilsonii Dunn is a PSESP (plant species with extremely small populations) with very limited genetic information to explore its endangered mechanism and conservation. In this study, we sequenced and assembled the complete chloroplast genomes of P. wilsonii using Illumina sequencing and compared its genomic sequences with those of four related Primula species. The chloroplast genomes of Primula species were similar in the basic structure, gene order and GC content. The detected 38 SSRs loci and 17 hyper-variable regions had many similarities in P. wilsonii, P. anisodora, P. miyabeana and P. poissonii, but showed a significant difference compared with those in P. secundiflora. Slight variations were observed among Primula chloroplast genomes, in consideration of the relatively stable patterns of IR contraction and expansion. Phylogenetic analysis based on chloroplast genomes confirmed three major clades in Chinese Primula, but the infrageneric sections were not in accordance with morphological traits. The P. poissonii complex was confirmed here and P. anisodora was the species that was most closely related to P. wilsonii. Overall, the chloroplast genome sequences provided useful genetic and evolutionary information for phylogeny, population genetics and conservation studies on Chinese Primula species.
Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate semi-natural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites were used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition, community evenness, and functional response traits. We found that extensively grazed pastures and within-site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting nest densities. Ant community evenness was high in wetter grasslands with low within-site variability in soil moisture and surrounded by a less diverse landscape. Fourth-corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within-site local variability in soil moisture and low intensity grazing promote ant species densities, and highlight the role of habitat temperature and humidity affecting on community evenness. We hypothesize that a higher diversity of land cover types in a forest-dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g. stochastic colonization), in shaping ant community structure in temperate semi-natural upland grasslands.
The predicted temperature increase caused by climate change is a threat to biodiversity. Male reproduction is particularly sensitive to elevated temperatures resulting in sterility. Here we investigate temperature induced changes in reproductive tissues and the fertility reduction in male Drosophila melanogaster. We challenged males during development and either allowed them to recover or not in early adulthood, while measuring several determinants of male reproductive success. We found significant differences in recovery rate, organ sizes, sperm production and other key reproductive traits among males from our different temperature treatments. Spermatogenesis and hence sperm maturation was impaired before reaching the upper thermal sterility threshold. While some effects were reversible, this did not compensate the earlier damage imposed. Surprisingly, developmental heat stress was damaging to accessory gland growth and female post mating responses mediated by seminal fluid proteins were impaired regardless of the possibility of recovery. We suggest that sub-lethal thermal sterility and the subsequent fertility reduction is caused by a combination of malfunctioning reproductive traits: inefficient functionality of the accessory gland and alteration of spermatogenesis.
Carnivore communities are extremely important for maintaining the structure/function of ecosystems. Exploring the carnivore coexistence can provide the data needed for the development of effective conservation strategies for endangered species. We aimed to (1) reveal the dietary composition of a carnivore community that inhabits the Everest region by analyzing molecular diets, (2) assess activity patterns by analyzing camera-trapping records. Dietary analysis revealed 22 food MOTUs of 7 orders and 2 classes. Snow leopard and wolf mainly preyed on ungulate mammals (%PR = 61%, 50%), while lynx and red fox mainly consumed small mammals (%PR = 62%, 76%). Higher dietary overlap (Pianka’s index = 0.95 ~ 0.97) was observed between similar-sized predators (snow leopard versus wolf, lynx versus fox); and there was no dietary difference between them (P > 0.05). Lower dietary overlap (Pianka’s index = 0.53 ~ 0.67) was observed between predators with large body size difference (snow leopard versus lynx, snow leopard versus red fox, wolf versus fox); and dietary difference was significant (P < 0.01), indicating the existence of dietary partitioning. In activity pattern analysis, predators exhibited higher temporal overlap with the more frequently consumed prey species, indicating that predator activity can be regulated by prey availability. Snow leopard and wolf had the higher activity overlap (Δ = 0.87) suggesting the lack of temporal partitioning. Red fox had the lower coefficients of overlap with snow leopard and wolf (Δ = 0.60, Δ = 0.59), suggesting that fox temporally avoid snow leopard and wolf slightly. We revealed the coexistence mechanisms of a carnivore community in the Everest region, by confirming that sympatric coexistence was facilitated by both dietary and temporal partitioning. These results will help to increase understanding of carnivore communities, and provide the scientific foundation for the conservation of threatened species in the Mount Everest region.
Although the COVID-19 lockdowns in 2020 had some environmental benefits, the pandemic’s impact on the global economy has also had conservation repercussions, especially in biodiverse nations. Ecuador, which is heavily reliant on petroleum, agricultural exports, and ecotourism, experienced a rise in poverty in response to pandemic shutdowns. In this study, we sought to quantify levels of illegal timber extraction and poaching before and after the start of COVID-19 lockdowns throughout two protected areas (Reserva Jama Coaque [JCR] and Reserva Bosque Seco Lalo Loor [BSLL]) in the endangered Pacific Forest of Ecuador. We analyzed chainsaw and gunshot acoustic data recorded from devices installed in the forest canopy from December 2019 to March 2020 and October 2020 to March 2021. Results from generalized linear mixed effects models indicated less chainsaw activity before lockdowns (post.lockdown = 0.571 + 0.196 SE, p-value = 0.004), although increased average rainfall also seemed to negatively affect chainsaw activity (avg.rainfall = -0.005 + 0.001 SE, p-value < 0.001). Gunshots were too infrequent to conduct statistical models; however, 87% of gunshots were detected during the ‘lockdown’ period. Observational data collected by rangers from these protected areas also noted an increase in poaching activities beginning mid to late 2020 and persisting into 2021. These results add to the steadily growing literature indicating an increase in environmental crime, particularly in biodiverse nations, catalyzed by COVID-19-related economic hardships. Identifying areas where environmental crime increased during pandemic lockdowns is vital to address both socioeconomic drivers and enforcement deficiencies to prevent further biodiversity loss and disease outbreaks and to promote ecosystem resilience. Our study also demonstrates the utility of passive acoustic monitoring to detect illegal resource extraction patterns, which can inform strategies such as game theory modeling for ranger patrol circuits and placement of real-time acoustic detection technologies to monitor and mitigate environmental crimes.
Resting stages of aquatic organisms that accumulate in the sediment over time are an exceptional resource that allows direct insights into past populations and addressing evolutionary questions. This is of particular interest in taxa that have recently faced environmental changes such as the Daphnia longispina species complex, a keystone zooplankton group in European freshwater ecosystems. However, genomic analysis might be challenging as many of these resting stages are very small and the DNA might be degraded. To reliably allow the resequencing of single Daphnia resting eggs from different sediment layers and characterize genomic changes through time, we performed whole genome amplification to obtain DNA amounts suitable for genome re-sequencing and tested multiple protocols involving egg isolation, whole genome amplification kits and library preparation. A pre-sequencing contamination screening was developed to quickly assess possible contamination. In total, we successfully amplified and sequenced nine genomes from Daphnia resting eggs that could be identified as Daphnia longispina species. We analyzed the genome coverage and SNP calling of these samples to optimize this method for future projects involving population genomic investigation of the resting egg bank.
Abstract 1. Classic evolutionary theory suggests that sexual dimorphism evolves primarily via sexual and fecundity selection. However, theory and evidence is beginning to accumulate suggesting that resource competition can drive the evolution of sexual dimorphism, via ecological character displacement between sexes. A key prediction of this hypothesis is that the extent of ecological divergence between sexes will be associated with the extent of sexual dimorphism. 2. As the stable isotope ratios of animal tissues provide a quantitative measure of various aspects of ecology, we carried out a meta-analysis examining associations between the extent of isotopic divergence between sexes and the extent of body size dimorphism. Our models demonstrate that large amounts of between-study variation in isotopic (ecological) divergence between sexes is due to systematic heterogeneity, which may be associated with the traits of study subjects. We then completed meta-regressions to examine whether the extent of isotopic divergence between sexes is associated with the extent of sexual size dimorphism. 3. We found a modest but significantly positive association between size dimorphism and sex differences in trophic level. Furthermore, the strength of this positive association varied between ecological contexts, increasing in species whose diets provide the greatest scope for trophic variation and in those for which body size is of greater relevance to feeding. 4. Our results therefore provide further evidence that ecologically mediated selection, unrelated to reproduction, can contribute to the evolution of sexual dimorphism.
Researchers' ability to accurately screen fossil and subfossil specimens for preservation of DNA and protein sequences remains limited. Thermal exposure and geologic age are usable proxies for sequence preservation on a broad scale but are of nominal use for specimens of similar depositional environments. Cell and tissue biomolecular histology is thus proposed as a novel proxy for determining sequence preservation potential of ancient specimens with improved accuracy. Biomolecular histology as a proxy is hypothesized to elucidate why fossils/subfossils of some depositional environments preserve sequences while others do not and to facilitate selection of ancient specimens for use in molecular studies.
Earth systems are nearing a global tipping point, beyond which the dynamics of biological systems will become unstable. One major driver of instability is species invasion, especially by organisms that act as “ecosystem engineers” through their modification of abiotic and biotic factors. In a mosaic landscape of non-invaded and invaded habitat, ecosystems modified through invasion may serve as “sink” habitat. To understand how native organisms respond to habitat that is becoming increasingly modified, it is essential to examine biological communities within invaded and non-invaded habitat, identifying compositional shifts between native and non-native taxa as well as measuring how modification has affected interactions among community members. Using dietary metabarcoding, our study examines the response of a native Hawaiian generalist predator to habitat modification by comparing biotic interactions across metapopulations of spiders collected in native forest and sites invaded by kahili ginger. Our study shows that, although there are shared components of the dietary community, spiders in invaded habitat are eating a less consistent and more diverse diet consisting of more non-native arthropods which are rarely or entirely undetected in spiders collected from native forest. Additionally, the frequency of novel interactions with parasites was significantly higher in invaded sites, reflected by the frequency and diversity of non-native Hymenoptera parasites and entomopathogenic fungi. The study highlights the role of habitat modification driven by an invasive plant in altering community structure and biotic interactions, appearing to serve as a “sink” for native arthropods and thereby threatening the stability of the ecosystem.
East Yunnan-Guizhou Plateau is rich in biodiversity in China. Complex geographical and climatic conditions, and rich bird resources made this area an ideal system for studying the spatial distribution mechanism and influencing factors of birds, which were still unknown. Bird community data from 37 sites in this region were collected, including 505 bird species and 164 species of resident passerine bird analyzed. The taxonomic diversity, phylogenetic diversity, functional diversity, and community structure index were calculated. Redundancy analysis (RDA), ordinary least square (OLS), and structural equation model (SEM), were used to explore the relationship between bird diversity index and 12 environmental factors used to describe the habitat conditions of birds. Results indicated that the vascular plant species richness, habitat area, and vertical altitude difference were the three most critical factors affecting bird diversity. The phylogenetic structure of bird community was dispersed in west and clustered in east, and significantly related to latitude, habitat area, and vertical altitude difference. The functional structure was dispersed in all sites, and significantly related to mean annual precipitation and longitude. This suggest that the distribution pattern of bird diversity was caused by the comprehensive action of various habitat factors which were mainly related to food availability and habitat heterogeneity. Considering the protection of birds in this area, it is necessary to continuously promote the construction of nature reserve system proposed by the Chinese government, and pay attention to the protection of urban green space such as campus and urban parks, to maintain the area and integrity of bird habitat, while only a high plant species and area is not enough, improving the habitat heterogeneity is of great significance.
Smooth-coated otters (Lutrogale perspicillata) and Malayan water monitor lizards (Varanus salvator) occupy similar habitats and and interact regularly in Singapore’s waterways. These interactions have a range of potential outcomes and are sometimes lethal. Few formal behavioral studies exist for either species. We analyzed interactions between otters and monitor lizards by gleaning data from publicly available videos from citizen scientists to examine what factors influence aggressive and defensive behaviors, and what influences vigilance in otters. Behavioral sequence analysis revealed no obvious monitor lizard behavior that predicted otter aggression towards monitors. We found that the presence and number of otter pups is positively associated with otter aggression. Otters also tended to be more vigilant in groups with more pups, and more vigilant on land than water. Monitor lizards displayed aggressive and defensive behaviors more frequently than did otters, regardless of whether the otters were aggressive towards lizards. These observations suggests that otters vary their aggression and vigilance levels depending on the context of each interaction.
1. Ombrotrophic peatbogs provide valuable records of environmental change on long timescales but are rarely preserved in an undamaged state near the major centres of industrial activity. Holcroft Moss is a rare example of an intact lowland peatbog in NW England, which provides a valuable opportunity to trace industrial impacts on vegetation in a sensitive environmental archive in close proximity to the early industrialising cities of Manchester and Liverpool. 2. We reconstructed the environmental changes of a Holcroft Moss before and after the Industrial Revolution using a high-resolution record of pollen, non-pollen palynomorphs, microcharcoal, peat composition (organic content, ash-free bulk density) and heavy metal content constrained by a radiocarbon and SCP (spheroidal carbonaceous particle) chronology. We examine the relationship between abiotic and biotic environmental tracers using principal components analysis and evaluate the role of local and regional climatic and anthropogenic drivers using canonical redundancy analysis and partitioning of variation. 3. Results show significant changes in bog vegetation composition during the last 700 years. From the 14th to 18th centuries AD, atmospheric climate variability and local agro-pastoral disturbance (grazing and fires) were the main drivers of vegetation change. From the mid-18th century onwards, the intensification of regional coal-fired industry contributed to increases in atmospheric pollutants such as dust, heavy metals and acid deposition that severely impacted vegetation, driving the decline of Sphagnum. Grasses subsequently rose to dominance in the 20th century associated especially with cumulative nitrogen deposition. Although atmospheric pollution significantly decreased after the Industrial Revolution, vegetation has not returned to previous pre-industrial conditions, reflecting the ongoing impact of external press drivers which pose challenges for conservation and restoration. 4. Synthesis. Palaeoecological studies are needed to reveal the long-term history of vegetation degradation and to offer guidelines for restoration and conservation practices.
Wildlife population dynamics are modulated by abiotic and biotic factors, typically climate, resource availability, density-dependent effects, and predator-prey interactions. Understanding if human-caused disturbances shape these processes is needed for the conservation and management of ecological communities within increasingly human-dominated landscapes. Garnering this understanding is difficult due to the lack of long-term longitudinal data on wildlife populations. Concurrently, the interplay between long-term human-mediated disturbances, climate, and predator density on ungulate population dynamics has been under-studied. Using a 50-year time series (1962-2012) on mule deer (Odocoileus hemionus) demographics, seasonal weather, predator density, and oil and gas development patterns from the North Dakota Badlands to investigate the long-term effects of landscape-level disturbance, we aimed to evaluate if harsh weather conditions in-combination with energy development and predators affected fall mule deer recruitment. We found that density-dependent effects and harsh seasonal weather primarily drove recruitment in the North Dakota Badlands. Recruitment was further shaped by interacting effects of harsh seasonal weather and predator presence in the form of high coyote density. Additionally, we found that fall recruitment was subtly modulated by interactions between seasonal weather and energy development (i.e., lower recruitment when harsher weather was combined with higher density of active oil and gas wells), and that the combined effect of predator density and energy development was not interactive but rather additive. Our analysis demonstrates the effect of energy development by modulating mule deer recruitment fluctuations concurrent with main recruitment drivers being biotic (density-dependency, habitat, predation) and abiotic (harsh seasonal weather, woody vegetation encroachment). A pattern emerges of density dependence, presumably due to limited quality habitat, being the primary factor influencing fall fawn recruitment in mule deer. Secondarily, stochastic weather events periodically cause dramatic declines in recruitment. Finally, the interactions between human disturbance and predation can be additive to the aforementioned drivers of recruitment and subsequently cause further declines.
The diet of an individual animal is subject to change over time, both in response to short-term food fluctuations and over longer time scales as an individual ages and meets different challenges over its life cycle. A metabarcoding approach was used to elucidate the diet of different life stages of a songbird, the Eurasian reed warbler (Acrocephalus scirpaceus) over the summer breeding season of 2017. The faeces of adult, juvenile and nestling warblers were screened for invertebrate DNA, enabling identification of prey species. Dietary analysis was coupled with monitoring of Diptera in the field using yellow sticky traps. Seasonal changes in warbler diet were subtle whereas age class had a greater influence on overall diet composition. Age classes showed high dietary overlap, but significant dietary differences were mediated through the selection of prey, i) from different taxonomic groups, ii) with different habitat origins (aquatic versus terrestrial) and iii) of different average approximate sizes. Our results highlight the value of metabarcoding data for enhancing ecological studies of insectivores in dynamic environments.
Invasive predatory species are frequently observed to cause evolutionary responses in prey phenotypes, which in turn may translate into evolution of the prey’s population dynamics. Research has provided a link between rates of predation and the evolution of prey population growth in the lab, but studies from natural populations are rare. Here we tested for evolutionary changes in population dynamics parameters of zooplankton Daphnia pulicaria following invasion by the predator Bythotrephes longimanus into Lake Kegonsa, Wisconsin, US. We used a resurrection ecological approach, whereby clones from pre- and post-invasive periods were hatched from eggs obtained in sediment cores and were used in a 3-month growth experiment. Based on these data we estimated intrinsic population growth rates (r) and carrying capacities (K) using theta-logistic models. We found that post-invasion Daphnia maintained a higher r and K under these controlled, predation-free laboratory conditions. Thus, whereas previous experimental evolution studies of predator-prey interactions have demonstrated that genotypes that have evolved under predation have inferior competitive ability when the predator is absent, this was not the case for the Daphnia. Given that our study was conducted in a laboratory environment and the possibility for genotype-by-environment interactions, extrapolating these apparent counterintuitive results to the wild should be done with caution. However, barring such complications, we discuss how selection for reduced predator exposure, either temporally or spatially, may have led to the observed changes. This scenario suggests that complexities in ecological interactions represents a challenge when predicting the evolutionary responses of population dynamics to changes in predation pressure in natural systems.
Morphology-based taxonomic research frequently applies linear morphometrics (LMM) in skulls to quantify species distinctions. The choice of which measurements to collect generally relies on the expertise of the investigators or a set of standard measurements, but this practice may ignore less obvious or common discriminatory characters. In addition, taxonomic analyses often ignore the potential for subgroups of an otherwise cohesive population to differ in shape purely due to size differences (or allometry). Geometric morphometrics (GMM) is more complicated as an acquisition technique, but can offer a more holistic characterization of shape and provides a rigorous toolkit for accounting for allometry. In this study, we used linear discriminant analysis to assess the discriminatory performance of four published LMM protocols and a 3D GMM dataset for three clades of antechinus known to differ subtly in shape. We assessed discrimination of raw data (which are frequently used by taxonomists); data with isometry removed; and data after allometric correction. We found that group discrimination among raw data was high for LMM, possibly inflated relative to GMM when visualised in PCA plots. However, GMM produced better results in group discrimination after the size and allometry treatments. High measurement redundancy in LMM protocols appears to result in relatively high allometry but low discriminatory performance. These findings suggest that taxonomic measurement protocols might benefit from GMM-based pilot studies, because this offers the option of differentiating allometric and non-allometric shape differences between species, which can then inform on the development of the easier-to-apply LMM protocols.
1. The Millennium Ecosystem Assessment assessed ecosystem change, human well-being and scientific evidence for sustainable use of biological systems. Despite intergovernmental acknowledgement of the problem, global ecological decline has continued, including declines in insect biodiversity, which has received much media attention in recent years. 2. Several roadmaps to averting biological declines have failed, due to various economic and political factors, and so biodiversity loss continues, driven by several interacting human pressures. Humans are innately linked with nature but tend to take it for granted. The benefits we gain from the insect world are broad, yet aversion or phobias of invertebrates are common, and stand firmly in the path of their successful conservation. 3. Providing an integrated synthesis for policy teams, conservation NGOs, academic researchers and those interested in public engagement, this article considers: (1) the lack of progress to preserve and protect insects. (2) Examples relating to insect decline and contributions insects make to people worldwide, and consequently what we stand to lose. (3) How to engage the public, governmental organisations and researchers through “insect contributions to people” to better address insect declines. 4. International political will has consistently acknowledged the existence of biodiversity decline, but apart from a few narrow cases of charismatic megafauna, little meaningful change has been achieved. Public values are reflected in political willpower, the progress being made across the world changing views on insects in the public should initiate a much-needed political sea-change, but only if we as entomologists enormously expand our engagement efforts.