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The present study was undertaken in the natural temperate Himalayan forests of Himachal Pradesh, India, to assess the tree species composition and diversity. For this purpose, six major forest types (FT) viz., FT1- Upper Himalayan Pinus roxburghii forest, FT2- Quercus leucotrichophora forest, FT3- Low-level P. wallichiana forest, FT4- Moist C. deodara forest, FT5- Western Mixed Coniferous Forest, FT6- Pinus gerardiana forest were selected. Detailed sampling was carried out in these forest types, and the sample plots in each forest type were laid out using the stratified random approach. Tree stem density varied from 191.11 N ha−1 (FT6) to 441.11 N ha−1 (FT2), whereas the tree total basal cover varied from 20.01 m2 ha−1 (FT6) to 47.59 m2 ha−1 (FT5). The diversity indices reflected that a total of 21 tree species (16 genera, 11 families) were identified, with tree species richness ranging from 3 (FT6) to 9 (FT1 & FT5). The forest type FT5 recorded the maximum Shannon index of diversity (2.36), Simpson Index of diversity (0.75), Margalef's Index of richness (1.37), pielou equitability (0.74), menheink index of species richness (0.49), whereas the highest Shannon Index of diversity (0.73) and species heterogeneity (0.85) in FT6 forest type. Furthermore, dominance-diversity (d-d) curves drawn that all the six forest types showed geometric curves reveals that one or two tree species are dominant in a particular forest type. Simultaneously, the research area's species diversity, tree stem density, and tree total basal cover were equivalent to those seen in other sections of Western Himalayas.

Late Quaternary carbonate dissolution was evaluated by using planktonic foraminifera indices perfect test ratio (PTR) of Goborotalia menardii, G. menardii fragmentation index (MFI), percentage of total resistant species (RSP) and sediment calcium carbonate (CaCO3) content in five sediment cores collected from two diverse oceanographic settings of the Indian Ocean. The cores collected from a depth range of 2000 and 4250 m of the Andaman Sea, a marginal sea in the Northern Indian Ocean and a seamount rise in the Central Indian Basin (CIB) in the abyssal Indian Ocean depict the intensity of selective carbonate dissolution in the glacial-interglacial cycles of the late Quaternary period. The assemblages from the Andaman Sea show little or no dissolution (deepest core AAS 11, water depth: ~3000 m), whereas cores collected from the CIB shows moderate to very high dissolution (SVBC 37, water depth of ~4000 m and core BC 37, water depth of ~4250 m). Excellent carbonate preservation in the Andaman Sea is reflected in the high order of species diversity consisting of thirty-five species. In contrast, selective dissolution in the CIB resulted in poor diversity with just about twenty-three species. The well-preserved planktonic foraminifera assemblages provide a better paleoceanographic record in the Andaman Sea. The carbonate dissolution proxies in the Andaman Sea point towards excellent preservation during Marine Isotope Stage 2 (MIS 2), especially during the deglacial period (Heinrich event 1) attributed to enhanced ventilation and deepening of carbonate compensation depth (CCD). Cores from the CIB demonstrate that the dissolution does not uniformly modify an assemblage due to the differential susceptibility of each species. Selective dissolution is an important issue in interpreting foraminiferal assemblages for climatic and environmental changes. The study reveals that the relationship between G. menardii abundances and its fragments in a single core is an effective parameter to understand the dissolution as its ratio is not affected by climatic or related environmental changes. Utmost care should be taken while using species variation as an evidence for climatic or related environment change from the CIB. The present investigation observes that the MFI can trace deep-sea carbonate dissolution quantitatively at both CIB and the Andaman Sea locations.

A monitoring survey was conducted in snake gourd agro ecosystem during the fruiting season at Gangnapur, West Bengal, India to generate extensive data on fruit fly diversity, population dynamics, infestation rates and evaluate the effect of trapping on fruit fly infestation rates vis-a-vis benefit cost ratio of snake gourd cultivation. Methyl Eugenol and Cue Lure traps were used to assess the fruit fly species diversity. The number of adult male flies trapped was used to calculate fruit fly per trap per day and assess the population dynamics. Bactrocera dorsalis, Zeugodacus cucurbitae and Zeugodacus tau were the predominant fruit fly species during the fruiting season. Maximum species diversity and evenness estimates were registered by Methyl Eugenol traps. Species richness estimates for Cue Lure and Methyl Eugenol traps during the entire experiment are analogous due to the trapping of two different types of fruit fly species. Zeugodacus cucurbitae is the most abundant species in the snake gourd ecosystem and dominated the community of fruit flies throughout the study. Fruit fly per trap per day values indicated that the Gangnapur area is at infestation level, for Zeugodacus cucurbitae and Bactrocera dorsalis, while, for Zeugodacus tau the area is at suppression level. The rate of infestation varied from 6.93 % to 44.09 %. Farmers with traps in their fields reported a benefit cost ratio of 0.73 to 4.63, while the no-trap group reported 0.34 to 1.56. This study at Gangnapur has proven the beneficial effect of trapping on the benefit cost ratio of snake gourd cultivation.

Tropical leaf phenology—particularly its variability at the tree-crown scale—dominates the seasonality of carbon and water fluxes. However, given enormous species diversity, accurate means of monitoring leaf phenology in tropical forests is still lacking. Time series of the Green Chromatic Coordinate (GCC) metric derived from tower-based red–greenblue (RGB) phenocams have been widely used to monitor leaf phenology in temperate forests, but its application in the tropics remains problematic. To improve monitoring of tropical phenology, we explored the use of a deep learning model (i.e. superpixel-based Residual Networks 50, SP-ResNet50) to automatically differentiate leaves from non-leaves in phenocam images and to derive leaf fraction at the tree-crown scale. To evaluate our model, we used a year of data from six phenocams in two contrasting forests in Panama. We first built a comprehensive library of leaf and non-leaf pixels across various acquisition times, exposure conditions and specific phenocams. We then divided this library into training and testing components. We evaluated the model at three levels: 1) superpixel level with a testing set, 2) crown level by comparing the model-derived leaf fractions with those derived using image-specific supervised classification, and 3) temporally using all daily images to assess the diurnal stability of the model-derived leaf fraction. Finally, we compared the model-derived leaf fraction phenology with leaf phenology derived from GCC. Our results show that: 1) the SP-ResNet50 model accurately differentiates leaves from non-leaves (overall accuracy of 93%) and is robust across all three levels of evaluations; 2) the model accurately quantifies leaf fraction phenology across tree-crowns and forest ecosystems; and 3) the combined use of leaf fraction and GCC helps infer the timing of leaf emergence, maturation and senescence, critical information for modeling photosynthetic seasonality of tropical forests. Collectively, this study offers an improved means for automated tropical phenology monitoring using phenocams.

Three species of the snakefly genus Inocellia Schneider, 1843 (Raphidioptera: Inocelliidae) are reported from the Hengduan Mountains in southwestern China. Among them, Inocellia yulongensis sp. nov. is described as new to science. Inocellia cheni Liu, H. Aspock, Yang & U. Aspock, 2010 is first recorded from Sichuan Province based on a newly collected male from a locality over 4200 m a.s.l. Inocellia obtusangularis Liu, H. Aspock, Yang & U. Aspock, 2010 is first recorded from Yunnan Province. The rich species diversity of snakeflies and its biogeographic significance from the Hengduan Mountains are discussed.

Elevational gradients in mountains show rapid changes in environmental conditions across a small geographic extent. This results in habitat specialization in animal communities which results in changes in species composition across space. We explore changes in species and functional group composition of ants using the first ever data on the distribution of ants across an elevational gradient in the Eastern Himalaya. Ants were sampled from 600 to 2400 m elevations at 200 m intervals using Winklers and pitfall traps. The sampling yielded 166 species of ants from 10,560 individuals, which were then classified into functional groups. We used redundancy analysis to test the effects of environmental factors (temperature, leaflitter volume, understory vegetation) and spatial predictors on species as well as functional group composition of communities at different elevations. Our results show that species diversity within all functional groups decreases towards higher elevations. The functional group composition of ant communities shows a gradient from high evenness at low elevations to being dominated by opportunist species at higher elevations. Redundancy analyses shows that most of the variation in species as well as functional group composition is driven by spatially structured environmental variation. This is most likely due to the high correlation between temperature and elevation. In summary, the changes in species as well as functional group composition are likely driven by a gradient in climate across the elevation gradient.

Microbial diversity is essential for the maintenance of the normal structure and function of bioregenerative life support systems (BLSS). As a typical nutrient-deficient environment (NDE), the BLSS does not provide sufficient types of available substrates for microbial communities, and its internal microbial diversity is usually not high due to interspecific competitive exclusion. However, it is reported that microbial diversity is abnormally high in the International Space Station (ISS) after long-term exposure to low-dose ionizing radiation (LDIR). It remains a mystery why LDIR leads to the formation and maintenance of high microbial diversity. In this study, a series of artificial microbial communities have been cultivated in NDE without and with LDIR, respectively. These communities are composed of three common microbial species (Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa) in the ISS. By comparing and analyzing the differences in the microbial physiological and behavioral response characteristics in the two scenarios, a reasonable hypothesis was put forward to elucidate the formation and maintenance mechanisms of high microbial diversity in NDE with LDIR. Then a set of kinetic models were developed based on this hypothesis, observed phenomena, and experimental data. Finally, these kinetic models were sufficiently validated and the hypothesis was fully confirmed through large-scale digital simulations. Briefly, two fundamental succession mechanisms of the microbial communities are supposed to exist in NDE with LDIR: substrate-based negative feedback regulation (SNFR) and microbial delayed responses. These two decisive succession mechanisms can give rise to asynchronously convergent fluctuations of microbial populations and significantly alleviate the interspecific competitions. Such a species-for-quantity strategy drives the microbial communities to form and maintain species diversity with higher richness and evenness. This study can lay the theoretical foundation and provide new ideas for the construction of advanced BLSS featured with more robust structures and stronger function.

The sources of toxic trace elements from the rivers to be debouched into the sea through estuaries are either weathered naturally from the soils and rocks or introduced anthropogenicaly from point or non-point sources, in labile form or in particulate form. The chemistry and ecology of an estuarine system are entirely different from the fluvial as well as the marine system. To gain a better understanding of the geochemical behavior of physico-chemical parameters, major ions and trace elements and to examine variations in associated chemical fluxes, 20 water samples were collected throughout the Manakudy estuary and analyzed during pre and post monsoon season. The major ion sequence of abundance is followed as Na > Mg > K > Ca > NO3 > SiO4 > P > NO2 with respect to the mean values during both monsoons. Among the trace metals, the mean concentration of Fe, Zn, Mn, and Pb are 4128, 42, 36, & 5.18 μg/l in premonsoon and 2064, 31,37, 25, & 6.17 μg/l in postmonsoon is found as high when compared to Cu, Cr, Cd and Co. To precisely identify the toxicity level of trace metals in water, the contamination factor (CF) and potential ecological risk index (PERI) were computed. Cu recorded as highly contaminating metal in estuarine water followed Zn based on CF values. The PERI values show moderate to high risk in premonsoon and moderate to significantly high risk in postmonsoon water. The physico-chemical parameters, major ions and trace elements are interrelated components of water quality properties which controls the estuarine water ecosystem. So that the enrichment and overloading of these components are by the geogenic and anthropogenic processes that adversely affects the species diversity, metabolism and the population of habitats. It is recommended for strategic management plans must be implemented to control the overloading of pollutants in Manakudy estuarine water.

The Qilian Mountain Grassland is an important animal husbandry production base in northwestern China. Horses, cattle, and sheep are the main livestock, which are widely distributed in the desert grasslands and alpine meadows around the Qilian Mountains. Grazing livestock produce large amounts of feces, and the germinable seeds in feces constitute the seed banks. Research on the size, plant species composition, and distribution of livestock dung seed banks in the Qilian Mountain grasslands may help understand the interactions between grass species and livestock and inform the comprehensive management practices for grazing livestock. In mid-October 2018, we collected the dung of horses, cattle, and sheep in the alpine meadows and desert grasslands of the Qilian Mountains and estimated the composition and size of the dung seed bank by the greenhouse germination method. Seeds of aboveground vegetation in the same location were also collected to determine the relationships between the size and composition of dung seed banks and the seed traits (i.e., mass and shape). A total of 30 plant species germinated from the dung seed banks of the three livestock species, of which 22 species (73%) were perennial. The seedling densities for horse, cattle, and sheep dung were 11.91, 10.80, and 7.60 seedlings per gram dung, respectively. The species richness, species diversity, and Jaccard coefficients of similarity between dung seedling and aboveground vegetation of horse dung were significantly greater than that of cattle and sheep dung. Regression analyses indicated that medium-sized (10−30 mg) and spherical (0.04−0.10 shape index) seeds had the greatest germination potential. Our study suggests that, of the three livestock species tested, the horse dung seed bank contributes most to grassland recovery and restoration of the Qilian Mountains.

Plant functional traits, especially leaf traits, are accepted proxies for ecosystem properties. Typically, they are measured at the species level, neglecting within-species variation. While there is extensive knowledge about functional trait changes (both within and across species) along abiotic gradients, little is known about biotic influences, in particular at local scales. Here, we used a large biodiversity-ecosystem functioning experiment in subtropical China to investigate intra-specific trait changes of 16 tree species as a response to species richness of the local neighbourhood. We hypothesized that because of positive complementarity effects, species shift their leaf traits towards a more acquisitive growth strategy, when species richness of the local neighbourhood is higher. The trait shift should be most pronounced, when a focal tree's closest neighbour is from a different species, but should still be detectable as a response to species richness of the directly surrounding tree community. Consequently, we expected that trees with a con-specific closest neighbour have the strongest response to species richness of the surrounding tree community, i.e., the steepest increase of acquisitive traits. Our results indicate that species diversity promoted reduced competition and complementarity in resource use at both spatial scales considered. In addition, the closest neighbour had considerably stronger effects than the surrounding tree community. As expected, trees with a con-specific nearest neighbour showed the strongest trait shifts. However, the predicted positive effect of local hetero-specificity disappeared at the highest diversity levels of the surrounding tree community, potentially resulting from a higher probability to meet a strong competitor in a diverse environment. Our findings show that leaf traits within the same species vary not only in response to changing abiotic conditions, but also in response to local species richness. This highlights the benefit of including within-species trait variation when analysing relationships between plant functional traits and ecosystem functions.

The loss of a particular species from a community may have different effects on its functioning, depending on the presence or absence of functionally similar or phylogenetically close species in that community (redundancy). Redundancy is thus defined as the fraction of species diversity not expressed by functional or phylogenetic diversity. We assessed functional and phylogenetic alpha- and beta-redundancy in helminth and flea assemblages of two species of South African rodents, Rhabdomys dilectus and Rhabdomys pumilio, using community uniqueness as the inverse indicator of redundancy. We asked whether patterns of functional and phylogenetic alpha- and beta-uniqueness differed between (i) parasite groups (endo- versus ectoparasites), (ii) host species within parasite groups, and (iii) biomes within host species. We found differences between the two hosts in the functional and phylogenetic alpha-uniqueness (but not beta-uniqueness) of flea, but not helminth, assemblages. Significant correlations between the alpha-uniqueness of parasite assemblages and the total parasite prevalence were found only for phylogenetic uniqueness and only in helminths. Pairwise site-by-site dissimilarities in uniqueness (beta-uniqueness) and pairwise dissimilarity in prevalence were significantly associated (positively) in helminths but not in fleas. A between-biome difference in functional (but not phylogenetic) alpha-uniqueness was found in both helminth and flea assemblages harboured by R. pumilio. We conclude that the resilience of parasite assemblages in terms of the effect on hosts depends not only on their transmission strategy but also on traits of host species and environmental factors.

Quercus semecarpifolia Sm. is a multipurpose, ecologically and economically important tree species of the sub-alpine ecosystem in the Indian Himalayan Region, forming a major part of the forests between 2800 and 3700 m amsl. Because of various natural and anthropogenic factors, populations of several forest species are dwindling in the region. This warrants the study of the population status, regeneration pattern, physicochemical properties of soil, and habitat suitability model of Q. semecarpifolia in the sub-alpine ecosystem of the Great Himalayan National Park (GHNP). In total, 37 populations, representing 4 habitats and 8 aspects between 2803 and 3613 m amsl and with 20–65° slope, were sampled to determine the species richness, density, total basal area, Species Diversity Index (H'), Concentration of dominance (Cd), and profile of the species. Among the populations, total tree density of Q. semecarpifolia ranged from 40 to 840 Ind ha−1, with a total basal area of 0.01–122.58 m2 ha−1, total shrub density of 240–1810 Ind ha−1, total herb density of 13.8–162.3 Ind m−2, total sapling density of 10–670 Ind ha−1, and total seedling density of 10–700 Ind ha−1. H' of trees ranged from 0.03 to 1.84, that of saplings between 0 and 2.44, of seedlings between 0 and 0.36, of shrubs between 0.43 and 2.28, and of herbs between 1.07 and 3.33. Cd for trees ranged from 0.00 to 1.00, that for saplings from 0.00 to 1.00, for seedlings from 0.00 to 1.00, for shrubs from 0.43 to 2.28, and for herbs from 0.07 to 3.33. Most individuals were in the range 73.6–94.5 cm circumference at breast height, and the least were in the ranges 136.6–157.5 cm and ≥ 220.6 cm. Seedlings and saplings were relatively very high in number. Tree density showed a positive correlation with total nitrogen (p ≤ 0.01, r = 0.35, n = 37) and a negative correlation with pH (p ≤ 0.01, r = -0.13, n = 37). The MaxEnt model calibration test for Q. semecarpifolia yielded satisfactory results (AUCmean = 0.899 ± 0.02). The BIO19 (precipitation in the coldest quarter) variable was the most influential and contributed 76.7% to the habitat model. The model identified an area of 145 km2 as suitable for reintroduction of the species in the GHNP. Frequent monitoring of species populations, standardization of propagation protocol for mass multiplication, awareness among the inhabitants, and establishment in in-situ and ex-situ conditions are recommended.

Fish migration in rivers is a growing area of concern as mounting anthropogenic influences, particularly fragmentation from dams and barriers, constitute major threats to global river species diversity. Barriers can impede the movement of fishes between areas critical to the completion of their lifecycle, affecting both population and ecosystem viability. In response, fish passage solutions have been identified as a critical need to maintain fisheries viability in the Laurentian Great Lakes, and around the world. Pivotal to the success of these fish passage solutions is a more complete understanding of the movement phenology and environmental cues that instigate migration. We used a dual-frequency identification sonar (DIDSON) to evaluate environmental triggers of river entry during spring and summer for three size classes of migratory fishes in the Boardman River, a Lake Michigan tributary. Our results indicate that medium size fish (>30 cm and

In southern Africa, archaeobotanical studies are intrinsically linked to prehistoric investigation and the discipline of anthracology has already proved its potential for palaeoenvironmental and palaeoecological reconstructions. While the region benefits from particularly good preservation of macro charcoal remains in its sites, anthracological studies remain underexplored and the methodological framework still needs to be developed and adapted to the diverse southern African ecological contexts. Here we provide a review of sampling methods and sample representativeness and we compare it with wood charcoal analyses performed in southern Africa. We used the charcoal-rich layers from the Later Stone Age sequence of Bushman Rock Shelter (BRS) to elaborate a sampling strategy producing samples that can both be analysed in a timely manner and that are statistically representative of the whole assemblage. In light of our results, we discuss the relevance of applying anthracological methods developed in European contexts. The evaluation of the taxa richness, diversity and size distribution at BRS leads to the recommendation of the identification of at least 500 charcoal fragments per stratigraphic unit. Thick layers should be split into two distinct samples, one comprising the top half and the other one the bottom half of the layer. The analysis of thin layers with limited charcoal abundance necessitates increasing the surface of sampling. All size-classes should be analysed to avoid any sampling bias.

Urban green spaces are often subject to intensive management and therefore only provide habitat for very few plant and animal species. Many studies have already proven that less intensive management of near-natural grassland habitats can increase species diversity, for example of butterflies. However, there is still a lack of knowledge as to what extent less intensive management of urban green spaces can promote urban butterfly diversity. Therefore, we examined parameters that determine the number of butterfly species in less maintained or even abandoned urban green spaces. We expected butterfly species richness and observation numbers to be affected by different management regimes. Butterfly surveys were carried out on 56 sites in the city of Hannover, Germany, in three consecutive years. The sites were subject to different management regimes. We explored parameters such as area size, the diversity of nectar plant species and habitat diversity for each site. A total of 34 species were recorded, with a minimum of 0 and a maximum of 17 species per site and year. The extreme drought and heat in 2018 clearly influenced the results of our study and this was reflected in massive decreases of observation numbers for some species. Less intensive management showed preferable effects in comparison to intensive management, but area size and nectar plants were more important factors influencing butterfly species richness and number of observations. Our results suggest that site parameters such as area size, nectar plant species richness or number of habitat types had stronger influences on butterflies than variations of extensive management. We conclude that less intensive urban green space management for good butterfly habitats is not a question of grazing, mowing or temporary abandonment, but instead must aim to increase nectar plant and habitat diversity.

Habitat loss and fragmentation are critical threats that cause biodiversity loss. However, the driving factors of species diversity in fragmented habitats are complex. This study was conducted in the agro-pastoral ecotone of northern China, a region that has suffered from severe habitat fragmentation due to agricultural activities. Based on the plant species richness, patch characteristics (patch area, fractal dimension, and isolation), landscape characteristics (grassland area ratio within buffer zones with different radii (50–500 m) around each patch), and environmental characteristics (mean annual precipitation, mean annual temperature, altitude, extremely high temperature, extremely low temperature, slope, and aspect) of 82 remnant grassland patches, we first explored the appropriate buffer zone with the most powerful impact on species richness of remnant grassland patches (SRP). Furthermore, we analyzed the relationships between a series of predictors and SRP. Finally, we confirmed the critical driving factors of SRP through a random forest analysis. The results showed that the landscape scale with the most powerful impact on SRP was 150 m. The patch area, grassland area ratio of a buffer zone with a 150 m radius, mean annual precipitation, and slope all had significantly positive effects on SRP. Among these factors, patch area and patch isolation were the top two driving factors of SRP. Our study suggests that large and highly connected patches should be protected for the construction of natural reserves. Meanwhile, the habitat around patches within a suitable range should also not be ignored. We highlight that the island biogeography theory could be used to predict plant species richness of remnant grassland patches in the agro-pastoral ecotone of northern China.

Bacterial symbionts in aphids are known to benefit the insect host and associated with aphid’s ecological adaptation. The pea aphid (Acyrthosiphon pisum), an important legume pest worldwide, carries at least eight endosymbionts, providing a model system to study insect–bacteria interactions. However, species diversity and geographic variations of endosymbionts are unknown in Chinese populations; therefore, we characterized symbiont communities and diversity of 27 pea aphid samples from 13 geographic populations of China. Via amplicon high-throughput sequencing and diagnostic PCR, we found that bacterial communities of Chinese populations were dominated by Proteobacteria and Firmicutes. Among eight known endosymbionts, five (Buchnera, Serratia, Hamiltonella, Regiella, and Rickettsia) were detected by both methods, with a specific geographical distribution. The obligate symbiont, Buchnera, was present in all aphid samples, while the four facultative symbionts showed a significant geographic variation. Each population was randomly infected with distinct endosymbionts, ranging from three to five species. Serratia and Rickettsia showed relatively higher abundance in central regions of China, Regiella was predominant in eastern and western China, whereas Hamiltonella showed an extremely low abundance and was absent in four populations. Samples grouped by altitudes showed a significant diversity difference, whereas there was no significant difference between red and green body colors. Bacterial community structures of the Chinese pea aphid populations were mainly influenced by environmental factors, other than body colors. These data can guide the development of potential biocontrol techniques against this aphid.

The process of community assembly is important to explain species coexistence and the maintenance of species diversity. Succession provides a good opportunity to study the role of the deterministic and stochastic processes during the community species composition. We investigated species composition and environmental factors and calculated the change in species diversity, phylogenetic diversity, net relatedness index, and nearest taxon index along a successional chronosequence, with a series of 0.5 × 0.5 m2 plots (n = 20) from five successional subalpine meadow plant communities (ages 1, 3, 5, 15, and 30) in the Qinghai-Tibetan Plateau. In the plots, we found a significant change in species composition and abiotic environmental factors. Our redundancy analysis showed that soil nitrate nitrogen and soil organic carbon were the key environmental factors that affect the community composition in succession gradient. The community showed an overdispersion phylogenetic structure along with the early and medium succession. The ends of the succession stage showed a random or convergent phylogenetic structure. The results showed that the construction process of plant communities in the early and middle stages of succession was mainly affected by habitat filtering. In the late stage of succession, the process of community construction is more complex, which could be affected by the limiting similarity and neutral driving process. Our findings are important to be used in managing ecological restoration and protection.

A survey of plant parasitic nematodes (PPN) abundance and diversity was conducted in foothills of Western Ghats at Coimbatore and Nilgiris districts in Tamil Nadu, India. Our study pointed to evaluate the PPN association with weeds, shrubs, and herbs including some agricultural crop cover both agro and forest ecosystems. Soil samples were collected around the rhizosphere of the plants and nematodes were isolated, counted under a microscope and identified by morphological characters. We collected 415 soil samples around the rhizosphere of 84 major plant families. Among 84 plant families, we found 13 PPN genera those generally responsible for cash crop yield loss. The genus Helicotylenchus spp., and Meloidogyne spp., were found frequent (226,136 samples) and rarely Hemicycliophora spp.,. The PPN diversity was measured by Shannon diversity index which showed that the diversity of PPN found higher in plant species those from the families Rosaceae (2.20) and Rubiaceae (2.13). We also recorded the PPN richness was dominated in four plant families. This result reveals that the PPN diversity and richness are positively correlated with host plant species diversity and altitude. Further, our study concludes that a wild plant in the forest ecosystem behaves like a reservoir of PPN.

DNA barcodes in species tagging have become a popular tool for taking inventories of species from different groups worldwide. The present study aimed to generate DNA barcodes of butterfly species from the Western Himalayas in Uttarakhand, India. The Indian Western Himalayan region (IWHR) has been explored to a limited extent about butterfly species’ diversity. However, the IWHR is prone to environmental change, and slight variations in climatic conditions can influence species diversity and change butterflies' range. The mitochondrial cytochrome c oxidase I (COI) gene was first used to generate the DNA barcode for butterflies from this region on a broad scale. 28 morphologically identified species, consisting of 102 sequences, were finally grouped into 26 species, with only two species showing ambiguity in species identification. These species had

The Middle Eocene Climatic Optimum (MECO) at ∼40 Ma is a significant global warming event associated with pronounced changes in the hydrosphere, atmosphere, and biosphere. The Kohat Formation in the Kohat Basin (eastern Tethys, Pakistan) is studied for identifying the response of larger benthic foraminifera (LBF) to MECO. The LBF assemblages in the Kohat Formation, covering from the Shallow Benthic Zones (SBZ) 15 to 17, suggest middle Lutetian to early Bartonian in age. Microfacies analyses indicate a lagoonal (inner carbonate ramp facies belt) to open marine (middle carbonate ramp facies belt) paleodepositional environment of the Kohat Formation. A distinct positive δ13C shift marks the stratigraphic position of the MECO in this formation. At the Peak-MECO event that is marked by the onset of the positive carbon isotope excursion (CIE), no evident compositional variation in the LBF assemblages is observed. However, significant changes in the LBF assemblages with the local first and last occurrences of some LBF genera can be observed in the Post-MECO and CIE recovery phase. These changes are verified by the sudden disappearance of Alveolina and orthophragminids and initial dominance of larger shell-size Nummulites fabianii, Heterostegina, and Linderina species accompanied by an increase in the species diversity. Here, we argue that the change in the observed LBF assemblages in the uppermost part of the Kohat Formation might be related to a larger foraminiferal turnover occurring during the Post-MECO event and corresponds to the CIE recovery phase.

Saudi Arabia has no permanent lakes or rivers but has wet meadows, which are desert wetlands temporarily formed due to the seasonal rainfall. This work investigates the environmental variables' impact on the vegetation pattern in the desert-wetland ecosystem in Taif highlands. Forty-one stands were randomly selected representing three main habitats (wet meadows, slopes, and terraces) to study their floristic features and vegetation analysis. A total of 142 species were recorded belonging to 111 genera and 45 families in the desert wetlands of Taif Province. About 64.1% were natural plants, while 25.4% were segetal weeds, 7.7% were aquatic plants, and 2.8% were plants that escaped from cultivation. Therophytes dominated over the other life forms, and mono-regional taxa were the dominant chorotype. Multivariate analysis of the recorded plants produced eight vegetation groups; four of them (A: Potamogeton nodosus-Nasturtium officinale, B: Lemna gibba-Leptochloa fusca, C: Typha domingensis- Xanthium strumarium and D: Conyza stricta- Cyperus longus) represented the wet meadows, while two (E: Acacia gerrardii- Commicarpus plumbagineus and H: Osteospermum vaillantii- Eragrostis Pilosa) for slopes and other two (F: Argemone ochroleuca-Cyperus rotundus and G: Pulicaria undulata- Solanum incanum) for the desert terraces. The vegetation zonation was clear, which started from real aquatic species in the wet meadows passing through mixed vegetation in the slopes and ended with proper xerophytic vegetation in the terraces. Conyza stricta- Cyperus longus community had the highest species diversity, while that of Potamogeton nodosus-Nasturtium officinale had the lowest. The principal component analysis indicated that HCO3, NO3, Mg, Cl, Ca, and pH values were the most effective soil variable. The presence of several segetal weeds suggests the alteration of the natural status of the desert-wetland ecosystem, and thus the conservation of these natural habitats becomes urgent.

Although insects are the most diverse evolutionary radiation on Earth, they have rarely occupied marine environments. Understanding the biology of such unique marine associated taxa can lead to insights into the adaptations and limitations of insects inhabiting such an environment. Here, we describe a new species of intertidal fireflies from the northeastern coast of the Atlantic Rainforest, recovered as sister to Micronaspis floridana in the first phylogenetic analysis of Cratomorphini taxa based on morphological data of adults and larvae. We review and redefine the intertidal firefly genus Micronaspis, based on the type species M. floridana, and M. gabrielae sp. nov. We provide descriptions, illustrations and behavioral records for both immature stages and adults, for each species, and indicate putative adaptations to the intertidal environment. Due to intense human occupation along the Atlantic Coast across the Americas, loss of habitat is a concerning issue for conservation efforts of all Micronaspis species. Given the disjunct distribution of the genus (Florida, United States of America and northern Bahamas, and Bahia, Brazil), species diversity could potentially be greater.

The aim of this study was to provide a baseline assessment of the turtle community in the coastal wetlands of the Greater Toronto Area. We documented turtle species diversity, abundance, reproductive classes, sex-ratios, and evidence of inter-wetland movement. Our study consisted of a series of mark-recapture surveys across eleven Lake Ontario coastal wetland complexes of the Greater Toronto Area performed between 2016 and 2019. We captured and marked 532 individual turtles of four native species (298 midland painted, Chrysemys picta marginata; 180 snapping, Chelydra serpentina; 7 Blanding’s, Emydoidea blandingii, and 5 map, Graptemys geographica) and three non-native species (40 red-eared slider, Trachemys scripta elegans; 1 false map, Graptemys pseudogeographica, and 1 Chinese softshell, Pelodiscus sinensis). Of note was the capture of an exceptionally large male snapping turtle, one of the largest recorded in Canada for both length and mass. The age classes of both snapping and midland painted species presented large proportions of breeding-sized adults, yet midland painted turtles showed a potential low recruitment with an underrepresentation of non-reproductive females. The sex ratios of both midland painted and snapping turtles across the whole waterfront did not differ from the expected 1:1 ratio. We also recaptured 198 turtles (135 midland painted, 53 snapping, 6 Blanding’s and 12 red-eared Sliders). The recaptured turtles revealed inter-wetland movements of 12 km over a two-year span for a midland painted turtle and an 8 km journey for a snapping turtle, potentially demonstrating some connectivity between geographically separate wetland complexes.

The rugged Himalayan landscape results in large variations in site conditions that regulate plant response to warming. There is lack of deeper understanding on plant response to warming under differing site characteristics in the mountainous terrain. A 2-yr experiment was conducted in the high mountains of Bhutan. The objective was to investigate the effects of short-term artificial warming on high-altitude grassland vegetation at north- and south-facing sites. An artificially warmed environment was simulated using open-top chambers (OTCs) that were compared with control chambers experiencing ambient conditions. Variables measured were species diversity, species richness, proportions of plant functional groups, forage dry matter, and forage quality. Generally at the north-facing site, OTC treatment showed a lower species diversity (OTC treatment H' ≈2.35; Control treatment H' ≈2.75), species richness (OTC treatment MI ≈1.38; Control treatment MI ≈1.45), sedge abundance (OTC treatment sedge cover ≈14.5%; Control treatment sedge cover ≈25%), and crude protein content (OTC treatment CP ≈6.60%; Control treatment CP ≈7.70%). On both sites, OTC treatment had a higher grass abundance (OTC treatment grass cover ≈24.0%; Control treatment grass cover ≈17.0%) and higher dry matter content (OTC treatment DM ≈1.70 t ha−1; Control treatment DM ≈1.50 t ha−1). The study suggests that climate warming triggers shifts in vegetation characteristics of high-altitude grasslands in the rugged mountainous terrain, but the magnitude of shift varies according to site characteristics. Under warming, the north-facing site could experience greater vegetation change, characterized by reduced species diversity, species richness, proportion of sedge, and crude protein content.

The study deals with the vertical distribution and seasonal dynamics of planktonic ciliates in the pelagic and littoral zones of a saline meromictic Lake Shira. Fourteen species of free-living ciliates have been found in the Lake, seven of them inhabiting the pelagic zone. The richness of ciliates is higher both in terms of the number of species and biomass in the littoral zone compared to the pelagic zone. Although the ciliate species diversity is low in the pelagic zone, in certain seasons, the biomass of some of the species may reach considerable values, up to 3.4 g m−2 in the water column. The biomass of ciliates in Lake Shira is generally comparable to the average values for other mesotrophic lakes. The abundance and composition of ciliate populations in Lake Shira vary considerably with depth. Changes in the Lake ecosystem caused by meromixis breakdown in 2015-2016, which induced considerable variations in many Lake components, affected the vertical distribution of planktonic ciliates. However, the annual average biomass of the species that inhabited the Lake before meromixis breakdown remained unchanged. The total ciliate biomass increased due to the presence of the new species.

The Tibetan Plateau of China is uniquely vulnerable to the global climate change and anthropogenic disturbances. As soil bacteria exert a considerable influence on the ecosystem function, understanding their response to different climates and land-use types is important. Here, we characterized the bacterial community composition and diversity across three major ecosystems (cropland, forest, and grassland) in the Sygera Mountains of Tibet, along a typical elevational gradient (3 300–4 600 m). The abundance of taxa that preferentially inhabit neutral or weak alkaline soil environments (such as Actinobacteria, Thermoleophilia, and some non-acidophilus Acidobacteria) was significantly greater in the cropland than in the forest and grassland. Furthermore, the diversity of soil bacterial communities was also significantly greater in the cropland than in the forest and grassland. We observed a unimodal distribution of bacterial species diversity along the elevation gradient. The dominant phyla Acidobacteria and Proteobacteria exhibited consistent elevational distribution patterns that mirrored the abundance of their most abundant classes, while different patterns were observed for Acidobacteria and Proteobacteria at the class level. Soil pH was the primary edaphic property that regulated bacterial community composition across the different land-use types. Additionally, soil pH was the main factor distinguishing bacterial communities in managed soils (i.e., cropland) from the communities in the natural environments (i.e., forest and grassland). In conclusion, land use (particularly anthropogenic disturbances such as cropping) largely controlled soil environment, played a major role in driving bacterial community composition and distribution, and also surpassed climate in affecting bacterial community distribution.

Species diversity is presently declining and homogenizing globally due to human land use changes and climate change effects. However, the causes of these declines are difficult to determine due to complex ecological interactions. Lepidopterans are a diverse and ecologically important group of insects that are declining in Britain and other parts of Europe. Long-term monitoring data made available in 2003 showed that 66% of observed species declined over the course of 35 years, however, it is not known what effect species losses has on ecosystem stability. Here, we assess long-term moth diversity dynamics in relation to climatic shifts over 20 years, and investigate the importance of stability in maintaining and conserving ecological communities. From 1993 to 2014, moth species data and abundances were recorded over 7,390 trapping nights. Overall, 376 species were recorded over 20-years, identifying seasonal and annual trends in species richness strongly associated with oscillations in temperature. Long-term stability, measured using mean-rank shifts and temporal variability, was indicative of significant positive associations between species diversity and temperature. Using rank shift analyses we were able to not only assess community stability dynamics, but also the individual species dynamics and their contribution to community diversity over time. We also noted generalist feeders were more associated with maintaining diverse species communities subjected to oscillating climatic conditions compared to specialist taxa. Overall, our study shows the benefit of utilizing community-based stability assessments to distill population level information from complex datasets, highlighting the need for long-term monitoring at the community level to explore impacts of environmental change on ecosystem function.

Land-use intensification, contrary to sustainable land management, has an impact on the healthiness of the environmental agroecosystem. To assess the environmental implications in abandoned land, olive groves and maize crops, the most sensitive and reliable edaphic indicators were measured to estimate plant species diversity and potentially toxic elements in soil, among different types of land-use. Species diversity presents a decrease in maize crops and olive groves compared to abandoned land. The families with the greatest species diversity were Poaceae, Asteraceae and Fabaceae in each land-use. From the results of the canonical correspondence analysis among species, sampling sites and selected environmental variables, a clear separation between species and sampling sites belonging to different types of land-use was found, presenting strong correlation with specific edaphic parameters (pH, Soil Organic Matter, Silt, Electrical Conductivity, Total Nitrogen, N O 3 - , P, K, Zn and Cu). Species diversity was reduced in maize crops due to anthropogenic interventions such as the excessive use of nitrogen and phosphate fertilizers and herbicides. Despite the fact that the lowest richness of plant species was found in olive groves, non-removal of crop residue preserves soil organic matter. In 7.4% of soil samples in olive groves, Cu total concentrations were over 100 mg kg-1 denoting polluted soils, while the potentially toxic concentrations of bioavailable copper fraction ( Cu DTPA ) probably lead to a decrease of species diversity. Future researches should therefore focus on the accumulation of toxic elements in agricultural land to preserve species diversity and a healthy environment.

While the effect of the global biodiversity crisis on local species loss is still debated, there is empirical evidence for major changes in local biodiversity attributed to increased species turnover. In communities exposed to a climate stressor, species turnover can lead to increased dominance of well-adapted species and consequently to an overall decline in species diversity. Despite the known importance of species turnover for community dynamics and functioning, experimental results on the connection between biodiversity loss and species turnover are scarce. We still do not fully understand which specific factors increase the rate of change in species composition, especially when considering natural compared to artificially lab assembled communities. In the present study, we experimentally tested whether a heatwave and dispersal increased species turnover and decreased species diversity in natural benthic diatom communities with different initial species compositions. We found that on the local scale, dispersal had overall positive effects on species richness while the relationship between exposure to the heatwave, species turnover, and diversity depended on initial community composition. However, on the regional (i.e. metacommunity) scale, exposure to the heatwave and dispersal both increased turnover and decreased Shannon diversity by almost 50%. Turnover in these metacommunities was not caused by a loss of species, but rather by a change in dominance patterns leading to homogenization, and consequently decreased diversity. Our study shows that climate change can destabilize community composition and degrade species diversity, but still after ca. 15 generations does not decrease the number of species in the community, demonstrating that the response of species diversity and richness to changing conditions can be fundamentally decoupled on ecological time scales.

Mustard fields (Brassica campestris: Brassicaceae) are mass flowering crops attracting a wide diversity of flower-visiting insects. Many studies have shown that the diversity of insects is higher near forest fragments than farther away from the forest edge and that Apis-bees numerically dominate such ecosystems. In this study, we investigated how insect diversity changes with distance from the forest edge (100 m, 1100 m, 2100 m) in mustard crop fields in Nepal. The effects of distance on both the abundance and richness of insects were evaluated using generalized linear mixed models, while Hill numbers were used to describe species diversity. We performed ordination analysis and PERMANOVA to examine the dissimilarity between insect communities at different distances. Finally, percent similarity was used to describe which insect species contributed most to the dissimilarity among distances. Our findings suggest that richness and abundance of the flower-visiting insects differed between distances of 100 m and 2.1 km from forest fragments. We found that values of all diversity measures were higher nearer to the forest fragments and moderately distant from the fragments. Accordingly, the ordination analysis corroborated the GLMMs, showing that insect community composition near to and moderately far from the forest fragments differed from that farther in the field. Additionally, we detected that solitary bee species (Andrena spp., Halictus spp. and Megachile lanata) outnumbered Apis-bees, greatly contributing to community discrimination among distances. Overall, we demonstrated that insect diversity within mustard crops is not homogeneous in Nepal. Cultivated plants farther from forest fragments are facing a deficit of diversity of flower-visiting insects. Furthermore, the role and the nesting habitat of solitary bees sampled here should be investigated, as they may contribute to mustard pollination in Nepal.

Progress in the identification of causal genes and understanding of the mechanism underlying kidney disease is hindered by the almost exclusive use of a few animal models with restrictive monogenic backgrounds that may be more resistant to kidney disease compared with humans and, therefore, poor models. Exploring the large genetic diversity in classical animal models, such as mice and rats, and leveraging species diversity will allow us to use the genetic advantages of zebrafish, Drosophila, and other species, to develop both new animal models that are more relevant to the study of human kidney disease and potential therapies.

A study was conducted to explore the plant biodiversity, phenology, life form and leaf size spectra of the vegetation of Biha Valley, District SWAT. The study area was surveyed thoroughly in different seasons of the year. Floristic diversity of the area consists of 202 plant species belonging to 154 genera and 70 families. There were two flowering seasons, 85.15% plant species flowers during May to August while 14.65% plant species flowers during the September to November. Biological spectrum of the area indicated that Therophytes (46.60%) was the dominant life form class, followed by Hemicryptophytes having 15.53%, Nanophanarophytes (11.65%), Megaphanerophytes (8.25%), Chamaephytes (7.77%), Geophytes (5.34%), Liana (2.91%) and Mesophanarophytes (1.94%). Leaf spectra of study area revealed that Microphylls was dominant with (41.26%) followed by Nanophylls (32.04%), Mesophylls (15.53%), Leptophylls (8.85%) and Megaphylls (2.91%).

East Asia has long been recognized as a major center for temperate woody plants diversity. Although several theories have been proposed to explain how the diversity of these temperate elements accumulated in the region, the specific process remains unclear. Here we describe six species of Carpinus, a typical northern hemisphere temperate woody plant, from the early Miocene of the Maguan Basin, southwestern China, southern East Asia. This constitutes the southernmost, and the earliest occurrence that shows a high species diversity of the genus. Together with other Carpinus fossil records from East Asia, we show that the genus had achieved a high diversity in East Asia at least by the middle Miocene. Of the six species here described, three have become extinct, indicating that the genus has experienced apparent species loss during its evolutionary history in East Asia. In contrast, the remaining three species closely resemble extant species, raising the possibility that these species may have persisted in East Asia at least since the early Miocene. These findings indicate that the accumulation of species diversity of Carpinus in East Asia is a complex process involving extinction, persistence, and possible subsequent speciation.

The plesiomorphic antenna with eleven articles is stunningly stable across the over 400.000 beetle species, despite the astonishing diversity of morphologies and ecological settings in which these organisms live. However, a few beetle lineages evolved different antennomere numbers, and these offer an interesting opportunity to understand how an otherwise fixed phenotype may eventually change, and to study what factors shape their patterns of variation. Here, we review for the first time, based on original and literature data, the unique patterns of variation in antennomere numbers in the firefly family (Coleoptera: Lampyridae), which has the greatest range (7–62) in antennomere numbers among beetles despite a relatively low species diversity (∼2000 species). We also tested the hypothesis that antennomere numbers are positively related to body size and explored patterns of antennal asymmetry across Amydetes spp, which have the greatest range in antennomere numbers (24–62). Out of the ∼100 firefly genera, nine show antennomere numbers lower or higher than 11. Among those nine genera with unusual antennomere numbers, five show intraspecific variation as well. In taxa whose antennae have less than 11 antennomeres, males seem to follow mainly light cues to find mates. In Amydetes, we found that antennomere numbers are positively related and negatively allometric to body size, suggesting that in this group the mechanism shaping antennal segmentation is sensitive to body size. Moreover, fluctuating asymmetry was found to be widespread in Amydetes spp., with a difference of up to six antennomeres between left and right antennae. The combined occurrence of unusual antennomere numbers and within-species variation suggests that in several firefly taxa a destabilization of the mechanism driving antennal segmentation has occurred.

Urban lawns provide space for recreation in cities, and they are an important part of urban green infrastructures. However, most lawns are intensively managed. As only few plant species can survive frequent mowing, urban lawns typically harbor only a limited number of plant species. To improve the biodiversity of urban lawns, it is often suggested to reduce the mowing frequency. Here, we studied the plant diversity of urban grasslands that have recently undergone management changes from mowing every few weeks to mowing only once or twice per season and compared them to intensively managed lawns. Within six years after the management changes, the grasslands with reduced mowing frequency hosted 30% more plant species than intensively managed lawns, and they were more heterogeneous both within and between grasslands. Additionally, the species composition of less frequently mown grasslands shifted from common mowing-tolerant lawn species to typical meadow species. Our study thus shows that the reduction of mowing is a simple and effective tool for increasing the biodiversity in urban grasslands.

Within the frame of the EU Common Agricultural Policy, most countries subsidise the establishment and maintenance of perennial flower strips on arable land within Agri-Environmental Schemes to provide foraging habitats and refuges for wildlife. In a replicated field experiment, we studied the effects of different types of seed mixtures on the establishment and maintenance of perennial flower strips on fertile arable land in the federal state of Saxony-Anhalt, Germany over seven years. The seed mixtures were commonly applied within recent Common Agricultural Policy funding periods: (1) a low-diversity cultivar standard seed mixture (CULTIVAR), (2) a high-diversity cultivar and native plant mixture (MIX), and (3) a high-diversity native plant mixture (WILDFLOWER). All plots were mulched every year in March and at the beginning of August. The low success of CULTIVAR triggered the massive encroachment of spontaneously established perennial grasses. In MIX, too, cultivars have disappeared after the first year. Both wildflower variants were successful in maintaining a high cover of sown perennial native forbs and a high ratio of established sown species, even after seven years. WILDFLOWER always tended to show better values than MIX. Furthermore, spontaneously establishing species began to spread their cover in MIX in the fifth year, with a very strongly increasing tendency, whereas in WILDFLOWER cover of spontaneously immigrating species stayed satisfyingly low. Using native wildflowers to establish perennial wildflower strips was very effective in maintaining high species diversity within the Agri-Environmental Schemes funding period of five years and beyond. WILDFLOWER was especially successful. On the other hand, CULTIVAR failed completely. On fertile soils in regions with rather low yearly precipitation, mulching twice a year supported the maintenance of perennial wildflower strips.

A variety of relationships have been observed between sexual dimorphism and species diversity, from positive to negative and nonsignificant. Although many hypotheses have been proposed to explain these relationships, it has proven difficult to understand why patterns are so variable. Most studies on this topic have used clades as phylogenetically independent replicates for pattern analysis, but a few recent studies took an alternative approach, using sites as spatially independent replicates. We discuss how the new, site-based studies complement the traditional, clade-based studies and argue that the combined use of the two approaches will be more powerful than either alone in understanding environmental factors that produce variation in sexual dimorphism-species diversity relationships.

This study investigates in detail species diversity of cyanobacteria which proliferated on the surface of diseased sponges and bedrock in Lake Baikal (Siberia, Russia) during the ecological crisis that has been progressing in the littoral zone since 2011 and caused numerous negative changes in biota. In 2014–2015, we examined samples from diseased and healthy sponges as well as rock substrates using Sanger sequencing and high-throughput 16S rRNA gene analysis. Based on morphology, we identified 15 cyanobacterial species in biofoulings. Tychonema sp., Symplocastrum sp., Pseudanabaena galeata and Tolypothrix distorta dominated on diseased sponges. In communities of healthy sponges, we detected mainly picocyanobacteria Synechococcus. Fascicles of Symplocastrum sp. and T. distorta dominated on bedrock substrates. Phylogenetically, most 16S rDNAs clustered among Tychonema, Pseudanabaena, Geitlerinema, Kamptonema, Leptolyngbya, and Tolypothrix spp. Cyanobacterial proliferation in the littoral zone of Lake Baikal should be considered as one of the most important negative ecological processes in recent times which requires an urgent study in order to understand the causes of its emergence and development. Mat-forming cyanobacteria Tychonema characterized by the highest tropism to sponges plays a special role in the disease and death of sponges.

Plant litter dynamics are sensitive to grassland productivity and the spatial heterogeneity of plant community. In this study, we investigated the effects of litter leachates on plant community characteristics using three plant species that represent different successional stages of alpine grasslands located on the Qinghai-Tibetan Plateau (QTP). We tested four concentrations of leachates (0, 50, 100, and 200 g L−1) from Kobresia setchwanensis, Elymus nutans, and Ligularia virgaurea. The leachates from the three plant species generally responded similarly, but the responses to the varying concentrations were significantly different. Addition of litter leachates negatively impacted the aboveground biomass and species richness. The Shannon-Wiener diversity index was positively correlated with the litter leachate addition. The effects of the litter leachate’s addition on plant functional groups varied—grasses were inhibited, forbs and legumes were promoted, and sedges were not significantly affected. This study demonstrates that litter leachates are a critical determinant of species diversity, grassland productivity, and community structure in QTP alpine grasslands.

Water mites of the genus Hydrodroma are common and frequently abundant in freshwater habitats on all continents other than Antarctica. Despite the broad geographic distribution, morphological differences between named species are minor and refer usually to one or two traits. DNA diagnostics may therefore prove useful for species delimitation in addition to morphological analyses. In this study, we use multiple statistical approaches, including Automatic Barcode Gap Discovery (ABGD), K2P distances, Neighbor-Joining (NJ) clustering and statistical parsimony (SP) based on mitochondrial cytochrome c oxidase subunit I (COI), and morphology to explore diversity among Hydrodroma species from North America and Europe. The results of ABGD confirmed species status of Hydrodroma despiciens (Muller, 1776), Hydrodroma pilosa Besseling, 1940, Hydrodroma torrenticola (Walter, 1908) from Europe and identified three species-level taxa from Canada, here provisionally called Hydrodroma sp. A, Hydrodroma sp. B and Hydrodroma sp. C. This outcome is congruent with NJ analysis that yielded a tree in which individuals clearly clustered into well-supported groups that matched described and putative species. The genetic distances between named and putative species ranged from 12.79% to 22.15%. Moreover, ABGD and NJ analyses based on COI sequences from our study and additional sequences available in GenBank and BOLD (Barcode of Life Datasystem) revealed five more clusters among North American Hydrodroma that likely also represent undescribed species. The results imply that future studies of Hydrodroma from other geographical locations and different habitat types are likely to reveal many more species of the genus. Moreover, this study highlights the potential utility of DNA barcoding in estimating true species diversity of the water mites, which is of fundamental importance in freshwater ecological studies and biodiversity surveys.

Great Lakes coastal wetlands (GLCWs) provide critical fish habitat. The invasion of GLCWs by hybrid and narrow-leaved cattail, Typha × glauca and Typha angustifolia (hereafter Typha), homogenizes wetlands by out-competing native plant species and producing copious litter. However, the effect of this invasion on fish communities is little known. To measure the effect of Typha on fishes, we established plots in Typha invaded and native wetland emergent zones in a northern Lake Michigan coastal wetland, and measured environmental variables, plants, and fishes in each zone over two summers. Dissolved oxygen and water temperature were significantly lower in invaded compared to native plots. Invaded plots were dominated by Typha and its litter; whereas. sedges (Carex spp.) were the most abundant species in native plots. Fish abundance and species richness were significantly lower in Typha compared to native wetland plots. The Typha fish community was dominated by hypoxia tolerant mudminnow whereas other small, schooling, fusiform species such as cyprinids and fundulids were absent. These results illustrate the negative impact of a dominant invasive plant on Great Lakes fishes that is expected to be found in Typha invasions in other GLCWs.

Changes in phytoplankton community composition and structure can have broad-scale ecosystem effects; however, drivers of species diversity in planktonic systems are not well understood. In lakes, a common but not thoroughly tested assumption is that shallow, nearshore waters are much more diverse and productive, and contribute considerably more material and energy to pelagic food webs than deeper waters farther offshore. Lake Superior is a large, cold, oligotrophic freshwater system which can provide insight into community organization under oligotrophic conditions. We used epilimnion and deep chlorophyll layer phytoplankton data from a lake-wide sampling program conducted in 2011 and 2016 to test whether assemblage composition, total algal biovolume, cell concentrations, diversity, and richness vary with depth. Although lake depth was an important factor in structuring assemblage composition, there were no clear nearshore-offshore gradients in cell density or biovolume despite the exposure of nearshore areas to higher concentrations of watershed-derived nutrients. Shannon diversity increased slightly with increasing depth, whereas richness was uncorrelated. Understanding of the nearshore-offshore patterns in phytoplankton community characteristics in the Great Lakes has implications for designing monitoring strategies and for considering how further changes in climate and nutrient deposition would affect the base of the food web.

Background Energy and water availability are essential for biodiversity maintenance. In addition to the independent effects of water and energy on biodiversity, recent studies clarified that the effects of interaction between water and energy availability were indispensable. Methods In this exercise, by combining the species presence information and the environmental predictors, we produced species distribution models at 20 × 20 arc-minute resolution for 193 Theaceae species. Initially, the ordinary least square (OLS) regression was used to examine the stationary relationships between Theaceae diversity and climate. The statistical effects of water and energy on species diversity were detected using Geographically Weighted Regression analysis (GWR). Furthermore, the contour plots were used to view the statistical effects of the water and energy interaction on species diversity. Results The OLS results suggested that both energy and water availability are related to Theaceae species diversity. In GWR regression, the spatial variation of energy and water showed high explanatory power to the diversity pattern of Theaceae species. The patterns in the residuals of both OLS and GWR regression varied geographically. Therefore, the results of GWR regression were kept for further analysis. The value of diversity-water slopes decrease changed from positive to negative in extremely wet regions; In extremely dry conditions, the value of diversity-energy slopes decrease faster than other regions. Conclusions Our results support the following findings: 1) the latitudinal distribution of Theaceae species was limited by thermal tolerance, which support the freezing-tolerance hypothesis in macro-ecology; 2) Theaceae species diversity are sensitive to the instability of precipitation, while the limitation from energy availability is weak; 3) the effects of water and energy on species diversity are strong in dry regions. Those findings can provide further implications for Theaceae species conservation under climate change scenarios.

Predicting how plant invasions influence decomposition processes is difficult, as multiple factors change with plant community alteration. Here, we examined the importance of various abiotic and biotic factors (litter quality (C:N), UV radiation, and macroinvertebrate access) in driving early decomposition processes in native California sage scrub (CSS) and in adjacent non-native grassland habitats. Many findings from our experiment were consistent with studies from semi-arid regions (e.g., UV radiation drove decomposition processes and high quality litter decayed more rapidly). However, the acceleration of litter decomposition in the non-native grassland relative to native California sage scrub (CSS) was unexpected and contrasts with studies of partially invaded CSS systems. Our results highlight that studies of invaded systems that still retain native species diversity should not be extrapolated to type-converted systems. We hypothesize that high grass cover in the type-converted grassland created conditions that enhanced soil moisture, bacterial abundance, and macroinvertebrate influence relative to the CSS, accelerating decomposition and reducing regional C storage.

Green roofs are gradually being accepted and implemented across North America as they can mitigate many of the negative effects that urban areas have on humans and the environment. As rooftops are filled with living plants, individual species need to be tested for longevity and suitability. Twenty-two plant species including herbaceous perennials, grasses, and sedum were evaluated on a green roof at substrate depths of 4.5, 10, and 20 cm over an eight-year period in East Lansing, Michigan. Plants were irrigated when needed during the first two years, but had to rely on natural rainfall thereafter. All five species of sedum were still present at the end of the eight-year period, but only seven of the 17 herbaceous perennials and grasses survived. Of the herbaceous perennials and grasses, Allium cernuum was by far the dominant species in both the 10 and 20 cm deep zones. Sporobolus heterolepis and Koeleria macrantha also established themselves in the 20 cm zone, but all other species were either only present in trace amounts or had completely disappeared. Substrate moisture was probably the major factor in terms of species survival and a drought during 2016 was likely the cause for the large loss of species. Deeper substrates supported a larger variety of species, but plant species diversity decreased over time at all substrate depths. This study emphasizes the fact that if herbaceous perennials and grasses are to be successful on green roofs, then irrigation may be critical to mitigate drought and maintain species diversity. It also points out the importance of long-term studies to accurately evaluate green roof plant communities and provides the framework for a continuation of the same study in other areas of the world.

The edaphic fauna plays an important role in the organic matter dynamics of the soil. Millipeds (Diplopoda), centipeds (Chilopoda) and isopods (Isopoda) are among the main components of the soil fauna. Vegetation structure represents one of the main factors influencing composition and diversity of these species that inhabit leaf litter and soil, what is particularly important in the Amazon Forest, where there are several singular vegetation types. Savannah and forest areas stand out in ferruginous hills, which represents one of the most poorly known and highly threatened ecosystems in the Amazon. However, sampling the edaphic fauna in high diversity sites represents a challenging task. Studies have shown that sampling method may influence observed patterns of diversity. From this perspective, the present study aimed to (i) investigate whether assemblages of Chilopoda, Diplopoda and Isopoda differ between vegetation types in the Amazon, (ii) indicate how biological parameters behave in such communities, (iii) identify which method or combination of methods is better suited to sample species richness and (iv) quantify the efficiency of each method regarding time of work and cost. Sampling was conducted by means of hand collection, leaf litter collection, hay-bait traps and soil sampling in four patches, two in the savannah (also called canga) and two in the forest. Richness was higher in forest habitats for Chilopoda and Diplopoda, while for Isopoda there was no significant difference. Species composition also differed between vegetation types for Chilopoda and Isopoda, but not for Diplopoda. Beta diversity between vegetation types was mainly determined by nestedness and balancing, while turnover was the main beta diversity component responsible for differences among methods. Soil sampling and hand collection added more species to the samples, therefore, this combination was the most efficient to access diversity. Our results support the hypothesis that differences in the soil cover promoted by distinct vegetation types influence the species diversity and composition of edaphic fauna. The differences were mainly determined by nestedness and balancing, indicating that the fauna sampled in the canga represents a subset of those present in the surrounding forest. In this sense, even in ecosystems with distinct vegetation types, the combination of soil and surface sampling methods is recommended. Lastly, the present study proposes a set of decision rules and a key to select the most appropriate method to sample the studied taxonomic groups.

Although the influences of desertification and nitrogen (N) addition in shaping species composition and community structure have long been explored, our understanding of the underlying processes is not yet strong. Analyses of trends in the turnover and nestedness components of beta diversity can be informative of the processes response to N addition and desertification in desert steppe ecosystems. Our investigation of the changes in beta diversity under desertification and N addition in a desert steppe ecosystem in northern China showed desertification to significantly decrease beta diversity among communities, which leads to species homogenization. Further, decreases to the turnover component of beta diversity was likely an important factor causing homogenization under desertification. Although nitrogen addition did not fundamentally influence beta diversity, dissimilarity caused by nestedness significantly increased with nitrogen addition. The contrasting effects of desertification and N addition on the turnover and nestedness components of beta diversity suggest that the ordered loss of plant species with desertification improvement. Overall, our findings provide strong evidence that the effects of desertification and N addition on beta diversity change with ecological processes. We recommend that conservation strategies that focus management practices on prevention of desertification will be most effective in maintaining species diversity.

In order to explore the species compositions and species diversity (Dominance (Do), Shannon-Wiener index (H′), Simpson diversity index (Dsi), Species richness (DMG), Pielou evenness index (Epi) and Frequency (Fr)) of twenty Arabis alpina L. var. parviflora Franch communities, field investigation was conducted in Huize county, Yunnan province, China. Some 20 A. alpina communities were distributed in two traditional smelting tailing piles of Minbingyingjiying (TST) and Shangduoduo village (SDD) with different Pb smelting history. The morphological characteristics (plant height, branch number, basal leaf length, basal leaf width and root morphology) of A. alpina, contents and accumulation characteristics of eight potentially toxic metals (As, Cd, Cr, Cu, Pb, Zn, Al, Fe) in soil and plants were analyzed. The results showed that the morphological characteristics of A. alpina were mean plant height 12.25 cm, the basal leaf length 17.69 cm, leaf width 5.40 cm, the total root length 117.86 cm plant−1, the root diameter 0.90 mm. The leaves of A. alpina in SDD were longer and narrower with higher plant height compared with in TST. The main companion plants of A. alpina were Sporobolus fertilis (Steud.) W. D. Clayt, Arenaria orbiculata Royle ex Edgew. et Hook. F. and Eulalia speciosa. (Debeaux). The H′ and Dsi were 0.56–2.04 and 0.44–0.95, respectively. The plant species numbers, H’, Dsi and Epi of A. alpina communities in TST were higher than those in SDD. Pb contents in shoot of two A. alpina samples were more than 1000 mg kg−1, Cd content in shoot of one A. alpina sample >100 mg kg−1 and Zn contents in shoot of seven A. alpina samples >10,000 mg kg−1 with the enrichment factors and transport coefficients greater than 1. The results indicate that A. alpina as a Zn, Pb and Cd hyperaccumulator, could be used for long-term phytoremediation of soils contaminated by Cd, Pb and Zn. Species diversity of A. alpina community during long-term natural vegetation restoration was high in the middle succession with single-peak model, and A. alpina would be dominant in the succession climax stage in potentially toxic metal contamination areas.

Stratification in lowland rainforests of Meghalaya, India, which represent the westernmost limit of the rainforests north of the Tropic of Cancer, was studied in horizontal and vertical planes to elucidate the patterns in stacking of species diversity and community attributes, and to draw comparisons with rainforests of ‘Indo-Malaya’ ecozone (biogeographical realm). All individuals ≥10 cm GBH (girth at breast height) were enumerated in six transects of 10 m width and up to 500 m length covering 2.45 ha area. The stratification of whole assemblage of species in vertical plane is referred to as ‘storey structure’ (=height class distribution), which explains structural complexity. In horizontal plane, it is typically referred to as ‘stand structure’ (=girth class distribution), which explains structural heterogeneity. The stratification of an individual species in vertical plane is referred to as ‘loftiness’ and in horizontal plane, it is frequently referred to as ‘population structure’. The stand structure was characterized by a negative exponential relationship or a reverse J-shaped curve, which is typical of a well regenerating forest stand. The storey structure was characterized by the low stature of the rainforest (