Multi-response Permutation Procedure Research Articles

Assessing Vegetation Composition and the Indicator Species around Water Source Areas in a Pine Forest Plantation: A Case Study from Watujali and Silengkong Catchments, Kebumen, Indonesia

This research aimed to assess vegetation composition and the indicator species around water source areas of pine forest plantation. Data were collected through interview and vegetation survey. Vegetation communities were first compared using multi-response permutation procedure (MRPP) analysis. Indicator species analysis was then employed to determine the indicator species for each condition by considering historical data from the interview. Canonical correspondence analysis (CCA) and simple correlation analysis were also included. The result showed significant differences in species composition between water source areas in Watujali (lower low flow) and Silengkong (higher low flow) catchments, indicated by T = −5.104, p = 0.000. Pinus merkusii was dominant in Watujali (important value = 78%, D′ = 0.62) compared to Silengkong (important value = 41%, D′ = 0.21), and in becoming an indicator species (value = 52.1, p = 0.042) for Watujali. Meanwhile, Laportea sinuata, as the specific tree of water source areas, was an indicator for Silengkong (value = 29.4, p = 0.004). At a smaller level, indicator species differentiated the two catchments, even though they shared similar in D′ and H′. Among specific plants of water source areas, only Ficus septica was an indicator for Watujali (value = 29.4, p = 0.004), given its adaptability. Specific plants of water source areas, including Laportea sinuata, Coctus spicatus, and Calocassia gigantea, were significant indicators for Silengkong catchments, illustrated by 34.6, 35.9, and 33.0 of indicator values, respectively. These results also reflected the relationship among tree vegetation change, environmental features, and the growth of smaller species, as implied by both CCA and simple correlation. This finding could be used as basic information for early assessment of environmental change and environmental restoration efforts around water source areas on pine forest plantations. Repetition of this study is suggested to be carried out in other pine forest areas, as each region sometimes has its own specific native and natural species.

Time in pasture rotation alters soil microbial community composition and function and increases carbon sequestration potential in a temperate agroecosystem

Soil carbon (C) sequestration plays an important role in mitigating global climate change, and certain land utilization strategies can exert a pronounced effect on carbon storage. Land use practices, such as planting previously cropped lands into perennial grasslands, can increase soil C sequestration; however, the temporal response of soil C pools to such changes in land use are likely complex and not well quantified. In the current study, a space-for-time approach was used to assess the response of soil C sequestration and microbial community composition during a five-year grazed pasture rotation following three years of vegetable production on a central Kentucky farm. After 5 years in pasture, soil organic C and N in the top 15 cm increased 20.6% and 20.1%, respectively, from year 1 levels, and particulate organic matter C (POM C) increased 53.5%. A carbon mineralization (CM) assay indicated that the potential release of CO2 also increased with time in pasture rotation. When compared to permanent pasture (not previously used for vegetable production), soil microbial community composition differed in rotation years 1–3 but became similar in years 4 and 5. Multi-response permutation procedure (MRPP) analysis showed that CM and POM were key factors affecting microbial community composition. Soil microbial community composition also varied with time of year (season), but to a lesser degree than with pasture duration. Overall, incorporation of perennial pasture into cropping systems can have profound effects on microbial community composition and function, increasing soil organic C, and consequently enhancing the potential for C sequestration; however, whether these increases in C storage persist throughout the full cropping sequence (i.e., once the pasture has been returned to vegetables) and/or how these changes influence subsequent vegetable production remains to be evaluated.

Differences exist in bird communities using restored and natural wetlands in the Parkland region, Alberta, Canada

Wetland restoration is used to compensate for historic and ongoing wetland losses. We compared bird community composition in 24 restored wetlands and 36 natural wetlands in the Parkland region of Alberta. Natural wetlands ranged in exposure to agricultural activity and were binned into three classes (low, medium, and high disturbance). Although the abundance and average species richness of birds were similar between restored and natural wetlands (analysis of variance: p > 0.22), the avian community composition differed significantly among wetland types (multiresponse permutation procedure [MRPP]: A = 0.05, p < 0.001). The avifauna using restored wetlands was distinct from the avifauna using natural wetlands spanning a range of disturbance levels (A = 0.02–0.06; p ≤ 0.006). Notably, restored wetlands were surrounded by less shrub/forest cover and more open water than low‐disturbance, natural wetlands. The majority (58%) of species using the surveyed wetlands were not classified as wetland‐dependent. Interestingly, if only wetland‐dependent species are considered, the avifauna using restored wetlands is no longer distinctive (MRPP: A < 0.01, p = 0.187), although the abundance of wetland‐dependent birds was marginally higher in restored wetlands (n = 24) than in low‐disturbance, natural wetlands (n = 10; Tukey's honestly significant difference test: p = 0.041). Overall, restored wetlands had reduced beta diversity compared to natural wetlands, regardless of whether the avifauna were restricted to wetland‐dependent species or considered comprehensively. This draws into question the legitimacy of the assumption that restoration can fully offset continued losses of natural wetlands.

Post‐fire vegetation recovery at forest sites is affected by permafrost degradation in the Da Xing'an Mountains of northern China

AbstractQuestionVegetation recovery and succession patterns after fire are not completely explained by the interactions of climate, disturbance, and species pool. Site‐specific factors can substantially change vegetation succession. We hypothesize that on sites exposed to fire and surface permafrost degradation, successional trajectories will produce different species assemblages than typical post‐fire succession.LocationDa Xing'an Mountains, northern China.MethodsVegetation and environmental data were collected at eight sites of past natural wildfire events. These sites represented different topographical situations, with four sites on slopes (lacking surface permafrost) and four sites in valleys (with surface permafrost). Three plots were established on each site, representing three different fire presence zones (burned, ecotone and unburned areas), giving a total of 24 plots. We used non‐metric multidimensional scaling (NMS) to describe post‐fire vegetation recovery at different sites and multi‐response permutation procedures (MRPP) to test our hypothesis.ResultsThe variation in dates of last fire was similar between the slope and valley sites. Slope sites that had been burned prior to 2003 had recovered to a composition similar to unburned sites by the time the study was conducted in 2017. However, none of the burned valley sites had fully recovered, even those exposed to fire in 1986, suggesting that the surface permafrost conditions affected the recovery pattern of vegetation. On burned valley sites, shrub species that are tolerant of saturated soils had become dominant and the number of tree saplings and seedlings became significantly lower than on the slope sites.ConclusionThe interaction of fire and topographic site type (through the influence of surface permafrost degradation) was revealed as a primary factor affecting species composition and tree density of post‐fire communities. On valley sites, melting of the surface permafrost after fire caused a failure of tree recruitment and prompted shrub species tolerant of saturated soils to become dominant.

Local- and Landscape-Level Variables Related to Poweshiek Skipperling Presence in Michigan Prairie Fens

AbstractThe Poweshiek skipperling Oarisma poweshiek, Lepidoptera: Hesperiidae is a historically common prairie butterfly with a range extending throughout prairie systems of the upper midwestern United States and southern Manitoba, Canada. Rapid, range-wide declines have reduced the number of verified Poweshiek skipperling locations to one in Manitoba prairie, one in Wisconsin prairie, and four in prairie fens in Michigan. Our objective was to investigate parameter suites with the potential to be biologically relevant to Poweshiek skipperling occupancy with the goal of informing conservation efforts. At 18 prairie fens categorized as occupied (n = 9) or unoccupied (n = 9), we collected information on plant biodiversity, water chemistry, soil chemistry, site geometry, and surrounding current and historical land cover at three spatial scales. To address the complexity of these systems, we used multiresponse permutation procedures and nonmetric multidimensional scaling to explore associations between variable groups thought to be relevant to Poweshiek skipperling (conditions for suspected larval host plants, system integrity, and agricultural influence) and occupancy categories. We used indicator species analysis to understand the relationships between plant biodiversity and Poweshiek skipperling occupancy at whole- and intrafen scales. Multiresponse permutation procedures analysis suggested that conditions for suspected larval host plants differed between occupied and unoccupied prairie fens. At the whole-fen scale, we identified 14 plant species associated with Poweshiek-occupied sites, including two purported larval host plants, Muhlenbergia richardsonis and Schizachyrium scoparium. At the intrafen scale, we identified 52 species associated with unoccupied Poweshiek sites, including many weedy species and those tolerant of inundated conditions. Our results can inform the evaluation of potentially suitable habitat for introduction and reintroduction efforts.

Multivariate analyses of the vegetation of the western Himalayan forests of Muzaffarabad district, Azad Jammu and Kashmir, Pakistan

Abstract Muzaffarabad district, Azad Jammu and Kashmir, Pakistan is part of the western Himalaya and rich in phytodiversity, but until now little was known about its plant diversity on larger spatial scale and vegetation composition through multivariate statistical tools. To fill this research gap, the whole district was ecologically explored for the collection of field data from August 2014 to July 2016. For vegetation studies, a total of 16 altitudinal transects comprising 110 sampling stations (samples) with 990 plots were studied by using a stratified random vegetation sampling method. Different multivariate statistical tools including Monte Carlo permutation test, Indicator species analysis, hierarchical clustering, ordination, variation partitioning and multi-response permutation procedures tests were used for the first time for the study area to elucidate the number of significant vegetation groups, ranking and placement of plant species in these groups, classification of vegetation units, detection of important gradients, importance of groups of environmental variables and pairwise compositional differences of the species groups respectively. The results showed that all the recorded 343 plant species belong to seven significant plant associations which were further placed into 5 major forest types. Out of the total 19 variables studied, CCA detected the significant contribution of the majority (simple effects: 12; unique effects: 8) of them. The latter (unique effects) in descending order included altitude, forest cover, deforestation, community maturity, forest density, latitude, slope aspect, and longitudinal variations. Similarly, variation partitioning results depicted that topography was the leading driver affecting vegetation distribution, followed by the biotic and edaphic factors. The forest edges, especially the sub-alpine ecosystem, were most diverse, supported higher tree density and also faced maximum deforestation pressure. Furthermore, rangelands in the temperate to alpine zones were affected by heavy overgrazing. Due to the disrupted local ecosystem functioning, the study area needs proper management and conservations plans to save its biodiversity wealth in this part of western Himalaya.

Low weight piglets show differences in intestinal microbiota, intestinal transcriptome and immune cell profile compared to high weight piglets during the first two weeks of lactation

Abstract Piglets born with lower weight and showing low performances during the first weeks of lactation are associated with higher risks of gastroenteric diseases after weaning. Therefore, we investigated the developmental differences between these pigs compared to the high weight piglets. Eight litters adjusted to 12 piglets were used. In each litter, piglets showing the lowest weight gain (LWG) or the highest weight gain (HWG)in the first week of life were selected. For each piglets enrolled, ileal gene expression, immune cell populations and microbiota profiles were studied. Results obtained from microarray and Q-PCR analysis showed that, at 16 days of age, the expression of genes involved in oxidative stress and immune response was altered in LWG piglets’ ileum. Analysis of the LH-PCR data of the microbiota using non-metric multidimensional scaling (NMS) and blocked multiresponse permutation procedure (MRBP) revealed that the microbiota of the HWG and LWG piglets tended to differ in ileal mucosa (p = .097) and differed incolonic lumen (p = .024). From day 8 to 16, LWG piglets failed to show an increase of CD21+ B cells in their blood (P weight × day = 0.01), but showed an increase of CD4+CD8α-Th cells (P = 0.002), unlike the HWG piglets. Percentages of CD14+ monocytes and other MHC-II+ cells were respectively higher and lower on day 8 compared to day 16 (P < 0.01). Moreover, LPS activated PBMC from LWG piglets produced less IL-6 (P < 0.05). These results suggest that piglets low performances during lactation affect the development of their immune system and is associated with differences in intestinal gene expression profile and microbiota.

Roosting Ecology of Black-Headed Ibis (Threskiornis melanocephalus) in Urban and Rural Areas of Southern Rajasthan, India

The roosting ecology of most waterbird species is poorly known and even less is known from southern Asia, where many species inhabit human-modified areas. Roosting ecology of the Black-headed Ibis (Threskiornis melanocephalus) was studied in urban and rural settings in southern Rajasthan, India. Analyses focused on assessing whether site characteristics varied between nest sites, urban and rural roost sites, and paired sites (i.e., a waterbird roost site near Black-headed Ibis roosts but without Black-headed Ibis). Additionally, the hypothesis that factors affecting Black-headed Ibis numbers at roosts would be similar at urban and rural sites was tested. Tree characteristics (canopy cover, girth at breast height) were different (P < 0.05) between nest and roost sites. Urban roost sites experienced 2.3 times greater disturbance than rural roost sites. Paired site characteristics were similar to urban roost sites (multi response permutation procedure, significance of δ = 0.3), but were dissimilar to rural roost sites. Co-occurring roosting bird assemblages were significantly different between roosts and paired sites (significance of δ < 0.01) in urban and rural settings. Black-headed Ibis numbers at urban roosts were influenced by multiple variables, but models showed considerable ambiguity at rural sites. Results strongly suggest that including roost sites in a species status assessment is important.

Coexistence of two sympatric flagship carnivores in the human-dominated forest landscapes of Northeast Asia

Understanding how large carnivore guilds survive in human-dominated landscapes is key to inform strategies for their conservation in the face of global carnivore declines. Amur tigers and leopards are recovering across the China-Russia border. However, knowledge is limited about competitive interactions between two large cats in Northeast Asia. To assess the spatial, temporal and combined spatiotemporal behavioral mechanisms potentially allow co-occurrence between tigers and leopards in a human-dominated forest landscape. Based on a large-scale camera-trapping data set in Northeast China, we used three different approaches for quantifying spatiotemporal associations: one spatial method (two-species occupancy model), one strictly temporal method (activity pattern overlap), and one spatiotemporal method based on multi-response permutation procedures at shared camera trap sites. Spatially, leopards showed no avoidance of the areas highly used by dominant tigers, but their diurnal activity pattern was significantly different from that of tigers. Spatiotemporal overlap analysis showed fine-scale behavioral avoidance when both co-occurred at camera locations, which further facilitates sympatry. Tigers spatially overlapped with humans, but they were less active during the day when human activities were more frequent. In areas with high cattle density, low occurrence of tigers and leopards may reflect the absence of sika deer, an important prey item for both species. This study provides the first empirical evidence that tigers do not limit leopard distributions, at least in our study area in Northeast Asia. Our results highlighted temporal segregation, not large-scaled spatial avoidance, as a key mechanism promoting coexistence of two large carnivores. Understanding these fine- spatial scale (i.e., camera locations) interactions between sympatric carnivores can help devise management strategies for predator guilds in human-dominated landscapes, currently a major global challenge.

Can fishways restore river connectivity? A case study using β diversity as a method of assessment

Abstract Aim β diversity was used as an indicator to test the hypothesis that a fishway can increase river connectivity, as a reduction in the value of this metric indicates greater similarity among fish assemblages. Methods Quarterly sampling was performed with gillnets upstream and downstream of the Porto Primavera dam, Upper Paraná Basin, before the opening of the fishway between February 1999 and May 2001, and between February 2003 and May 2005 with the fishway in operation (10 samples per period/site). The correlation between the fish assemblages and sites was verified by applying two Mantel tests (downstream versus upstream before and one equivalent after the fishway) using the distance matrices generated by the Bray‐Curtis index. The β diversity between downstream and upstream was calculated using the Sørensen index for each sample for the comparison of such values before and after the operation of the fishway, which were tested with Asymptotic Wilcoxon-Mann-Whitney Test. To summarize changes in the structure of the fish assemblages between the sites and periods nonmetric multidimensional scaling (NMDS) was applied based on Bray-Curtis dissimilarities, using multi-response permutation procedures (MRPP). Results The Mantel tests showed no correlation between the upstream and downstream assemblages before the operation of the fishway but greater correlation after. β diversity was lower after than before the fishway, representing an increase in similarity between downstream and upstream with the fishway. MRPP analysis indicated that the fish assemblages between the sites differed more than was expected by chance, with smaller divergence between the sampling sites after the fishway (A = 0.08) than before it opened (A = 0.09). Conclusions Although fishways remain an incipient and controversial theme for neotropical fish, the Porto Primavera fishway appears to be effective in terms of the restoration of connectivity.

Helonias bullata(Swamp Pink) Habitat Characteristics under Different Landscape Settings at Fort A.P. Hill, Virginia

Helonias bullata (Swamp Pink) is a federally threatened plant found in many of the wetlands throughout US Army Garrison, Fort A.P. Hill, VA. Wetlands that support Swamp Pink are exposed to periodic occurrences of wildland fire. However, much is not yet known about the relationship between this species and wildland fire. This study examines plant-level characteristics (i.e., number of leaves, rosette size) in relation to habitat-level characteristics through comparison of Swamp Pink under 2 land-management regimes in different military training zones. We evaluated the forest compositional differences based on the presence/absence of wildland fire and military-training zone in wetlands supporting Swamp Pink and in adjacent uplands using non-metric multidimensional scaling (NMS), multi-response permutation procedures (MRPP), indicator-species analysis (ISA), and measures of density, dominance, herbaceous cover, and species richness. Swamp Pink rosettes in wetlands exposed to fire were significantly larger and averaged nearly 1 more leaf per rosette as compared to those surveyed in wetlands that were not exposed to fire. There was significantly less upland tree density in burned sites compared to unburned sites. We found no relationship between training zones and Swamp Pink size and the number of leaves. Additional differences in forest composition were revealed by comparing training zone and the presence/absence of wildland fire in conjunction with one another. Compared to other areas, the training zones with lower fire-frequency and recent evidence of fire featured significantly larger rosettes with more leaves. In uplands, overall community composition was significantly different among plots exposed to different fire-management strategies (MRPP; P 0.05). This finding suggests that wetlands limit the effects of fire on community composition. ISA showed that in both wetlands and uplands, different species characterized areas with differing fire influence, suggesting some influence by wildland fire even when such effects were not reflected in overall changes to community composition. The results of this study, the life-history of Swamp Pink, and the distribution of the species in ecosystems characterized by fire (e.g., the New Jersey Pine Barrens) suggest that Swamp Pink is not negatively impacted by fire to a significant degree. The conservation of the Swamp Pink habitat at Fort A.P. Hill may in fact benefit from periodic occurrences of wildland fire. Further research is warranted.

Effects of cover soil stockpiling on plant community development following reclamation of oil sands sites in Alberta

Stockpiling of cover soil can influence vegetation development following reclamation. Cover soil, comprising the upper 15–30 cm of the surface material on sites scheduled for mining, is commonly salvaged prior to mining and used directly or stockpiled for various lengths of time until it is needed. Salvaging and stockpiling causes physical, chemical, and biological changes in cover soils. In particular, stockpiling reduces the availability and vigor of vegetative propagules and seed, and can lead to increases in the abundance of some weedy species. This study uses data from monitoring plots to assess how stockpiling of cover soil impacts plant community development on reclaimed oil sands mine sites in northern Alberta. Development of plant communities differed distinctly between directly placed and stockpiled cover soil treatments even 18 years after reclamation. Direct placement of cover soil resulted in higher percent cover, species richness, and diversity. Nonmetric multidimensional scaling and multiresponse permutation procedure revealed compositional differentiation between the treatments. Indicator species analysis showed that direct placement treatment was dominated by perennial species while grasses and annual forb species dominated sites where stockpiled soil was used. Results indicate that stockpiling leads to slower vegetation recovery while direct placement of cover soil supports more rapid succession (from ruderal and annual communities to perennial communities). In addition, direct placement may be less costly than stockpiling. However, scheduling of salvage and placement remains a challenge.

Species composition and diversity of ground bryophytes across a forest edge-to-interior gradient

Understanding diversity patterns and community structure of bryophytes will help integrate nature conservation at multiple biotic-group levels. We conducted a survey of ground bryophytes in a subtropical forest along an edge-to-interior gradient in South China. We recorded 11 liverwort species from 10 genera of seven families, and 26 moss species from 23 genera of 16 families in three transects. A two-way cluster analysis detected the environmental gradient between the forest edge and forest interior for bryophytes with habitat specificity. Functional diversity of bryophytes differed significantly across an edge-to-interior gradient. The range and median in both structural and functional diversity decreased remarkably from the forest edge to the interior. Multi-response permutation procedures showed significant differences in species composition between the forest-edge and forest-interior, and between the intermediate and forest-interior transects. Seven species were detected with a significant indicator value for indicating environmental conditions in the forest edge, while only one such species was found indicative of the intermediate transect. Our results demonstrate that remarkable edge effects exist for species composition and functional diversity patterns, and the forest edge is a marginal habitat with high biotic heterogeneity. Furthermore, functional diversity metrics are more sensitive to the edge effect than species diversity.

A Comparison of Five Wetland Communities in a North Dakota Fen Complex

Fens are rare and not well-studied within the Prairie Pothole Region (PPR) of North Dakota. PPR wetlands (including fens) are vulnerable to land use alterations, particularly conversion to agricultural production. In this study, we described a 48-ha natural fen complex with five distinct wetland plant communities (denoted cattail [Typha L. spp.], floating mat [areas at higher elevation with an upward groundwater gradient], herbaceous, tree, and wet meadow). Our goal was to describe the wetland plant communities and determine possible factors driving the formation of several distinct wetland plant communities in close proximity to one another. We identified 148 plant species, six of which are considered priorities for conservation by the North Dakota Natural Heritage Program. We compared the composition of wetland plant communities using multi-response permutation procedure (MRPP) and examined individual attributes (e.g., species richness, evenness, diversity, Floristic Quality Index, percent introduced species, percent soil organic matter, pH, and electrical conductivity) of the wetland plant communities using ANOVA and Tukey's (HSD) test. We found the highest species richness, evenness, and diversity in herbaceous and tree communities and the lowest percent introduced species in floating mat communities. There were no significant differences in the soil properties tested among the five plant communities.

Area effect of distribution of Silphids (Coleoptera, Silphidae) on Korean islands

Abstract We investigated the spatial patterns in the distribution of carrion beetles on 26 islands to test the area and distance effects on species diversity. The relationships between species richness and assemblage and island area, distance from the mainland, and shortest distance from the largest island within 2 km were analyzed using linear regression, Canonical Correspondence Analysis (CCA) and Multi-Response Permutation Procedures (MRPP). We hypothesized that both area and distance from the mainland played a significant role in species richness, while geographic location in the sea influenced aggregation of carrion beetles on islands. Area was the only factor influencing species richness of carrion beetles on islands. Moreover, distance from the mainland and close islands did not significantly influence to carrion beetles. In addition, geographic location in the same Sea did not influence beetle assemblages. Taken together, the results of this study indicated that carrion beetles on Korean islands were largely affected by island size and that dispersal was stochastic.

The inclusion of overlooked lichen microhabitats in standardized forest biodiversity monitoring

AbstractEpiphytic lichens are increasingly included in forest biodiversity monitoring schemes, but most of the standardized guidelines consider only lichens colonizing a small part of tree trunks (1·0–1·5 m) and overlook other important microhabitats, such as fallen branches and stumps. In this paper, we present results of a small-scale pilot study to evaluate the possible advantage of including four distinct microhabitats in standardized procedures for assessing epiphytic lichen diversity. Trunk bases, trunks between 100 and 150 cm above the ground, stumps, and fallen branches were each sampled with a different standardized sampling method along a forest age gradient in temperate deciduous forests of the Caucasian region. Plot-level species richness was contrasted between the standardized sampling procedures of different substrata and a non-probabilistic floristic sampling. The interactions between sampling procedure and stand age were analysed using linear mixed models, and non-metric multidimensional scaling (NMDS) and multi-response permutation procedures (MRPP) were used for comparing species composition. Overall, 97 species were recorded, their richness increasing with increasing stand age. Results were consistent across the gradient of stand age and demonstrated that the adoption of standardized sampling procedures which include stumps and fallen branches in addition to tree trunks would increase the capability of maximizing species capture. This approach would allow researchers to evaluate lichen patterns by simultaneously considering the response of different communities sensitive to different stand-related factors. Despite the likelihood that a non-probabilistic floristic survey would give a more exhaustive picture of the plot-level lichen diversity, standardized sampling procedures that include tree trunks, fallen branches and stumps are likely to represent a reasonable trade-off between exhaustiveness and cost-effectiveness.

Changes of arthropod diversity across an altitudinal ecoregional zonation in Northwestern Argentina.

This study examined arthropod community patterns over an altitudinal ecoregional zonation that extended through three ecoregions (Yungas, Monte de Sierras y Bolsones, and Puna) and two ecotones (Yungas-Monte and Prepuna) of Northwestern Argentina (altitudinal range of 2,500 m), and evaluated the abiotic and biotic factors and the geographical distance that could influence them. Pitfall trap and suction samples were taken seasonally in 15 sampling sites (1,500–4,000 m a.s.l) during one year. In addition to climatic variables, several soil and vegetation variables were measured in the field. Values obtained for species richness between ecoregions and ecotones and by sampling sites were compared statistically and by interpolation–extrapolation analysis based on individuals at the same sample coverage level. Effects of predictor variables and the similarity of arthropods were shown using non-metric multidimensional scaling, and the resulting groups were evaluated using a multi-response permutation procedure. Polynomial regression was used to evaluate the relationship between altitude with total species richness and those of hyperdiverse/abundant higher taxa and the latter taxa with each predictor variable. The species richness pattern displayed a decrease in species diversity as the elevation increased at the bottom wet part (Yungas) of our altitudinal zonation until the Monte, and a unimodal pattern of diversity in the top dry part (Monte, Puna). Each ecoregion and ecotonal zone evidenced a particular species richness and assemblage of arthropods, but the latter ones displayed a high percentage of species shared with the adjacent ecoregions. The arthropod elevational pattern and the changes of the assemblages were explained by the environmental gradient (especially the climate) in addition to a geographic gradient (the distance of decay of similarity), demonstrating that the species turnover is important to explain the beta diversity along the elevational gradient. This suggests that patterns of diversity and distribution of arthropods are regulated by the dissimilarity of ecoregional environments that establish a wide range of geographic and environmental barriers, coupled with a limitation of species dispersal. Therefore, the arthropods of higher taxa respond differently to the altitudinal ecoregional zonation.

Pond permanence is a key determinant of aquatic macroinvertebrate community structure in wetlands

Abstract Globally, many aquatic ecosystems experience periodic desiccation that imposes stress on biota. The Northern Prairie Pothole Region (NPPR) in Alberta, Canada, contains abundant wetlands that fill with spring snowmelt and then draw down throughout the summer. They are often assigned a pond‐permanence class based on the duration of ponded water. These dynamic wetlands are home to diverse and productive communities of macroinvertebrates. We expected that pond permanence structures macroinvertebrate communities in NPPR wetlands. In addition to exploring the taxonomic composition of macroinvertebrate communities, we aimed to characterise these communities by functional groups to test for associations between pond permanence and desiccation strategies, feeding groups or behavioural guilds. We sampled aquatic macroinvertebrates from 87 wetlands in the NPPR that spanned a range of pond‐permanence classes. We identified macroinvertebrates to the lowest practical taxonomic level, usually family. We then performed multivariate analyses (multiresponse permutation procedures, non‐metric multidimensional scaling) to identify differences in community composition and functional groups among permanence classes. Community composition of macroinvertebrates was statistically distinct among pond‐permanence classes, with the extremes of temporarily‐ and permanently‐ ponded wetlands differing most. Notably, macroinvertebrates in temporarily‐ ponded wetlands were not unique taxa specially adapted to low‐permanence wetlands, but rather a subset of the community found in more permanent wetlands. In other words, macroinvertebrates at the family level exhibit a nested pattern of diversity best predicted by the permanence of ponded water in wetlands.

Macroinvertebrate‐based bioassessment of rivers in Addis Ababa, Ethiopia

AbstractChemical‐based studies have shown pollution of rivers in Addis Ababa, Ethiopia. However, as bioassessment is not a component of the river assessment and monitoring programmes, information on the ecological status of the rivers is limited. The study assessed the ecological status of the Little and Greater Akaki Rivers using macroinvertebrates. Macroinvertebrates were collected from twelve sites twice in the dry and wet seasons. There was abundance of few tolerant, collector‐gatherer taxa with a loss of most sensitive taxa that used to be part of the river systems. Macroinvertebrate communities from upper and lower reaches showed complete differentiation on the nonmetric multidimensional scaling (NMS) ordination graph with upstream reaches composed of relatively sensitive taxa while the lower reaches dominated by tolerant taxa. Multiresponse permutation procedure (MRPP) showed significant difference between the two reaches. Macroinvertebrate communities from the dry and wet seasons did not show differentiation on the NMS ordination graph and MRPP did not show significant difference. Both rivers scored low in the South African Scoring System (SASS 5) and ETHbios, indicating ecological degradation. The results suggest that several decades of environmental degradation might have led to impoverished regional species pool, consisting mainly tolerant and generalist taxa constant throughout the year.

Anthropogenic water sources and the effects on Sonoran Desert small mammal communities.

Anthropogenic water sources (AWS) are developed water sources used as a management tool for desert wildlife species. Studies documenting the effects of AWS are often focused on game species; whereas, the effects on non-target wildlife are less understood. We used live trapping techniques to investigate rodent abundance, biomass, and diversity metrics near AWS and paired control sites; we sampled vegetation to determine rodent-habitat associations in the Sauceda Mountains of the Sonoran Desert in Arizona. A total of 370 individual mammals representing three genera and eight species were captured in 4,800 trap nights from winter 2011 to spring 2012. A multi-response permutation procedure was used to identify differences in small mammal community abundance and biomass by season and treatment. Rodent abundance, biomass, and richness were greater at AWS compared to control sites. Patterns of abundance and biomass were driven by the desert pocket mouse (Chaetodipus penicillatus) which was the most common capture and two times more numerous at AWS compared to controls. Vegetation characteristics, explored using principal components analysis, were similar between AWS and controls. Two species that prefer vegetation structure, Bailey’s pocket mouse (C. baileyi) and white-throated woodrat (Neotoma albigula), had greater abundances and biomass near AWS and were associated with habitat having high cactus density. Although small mammals do not drink free-water, perhaps higher abundances of some species of desert rodents at AWS could be related to artificial structure associated with construction or other resources. Compared to the 30-year average of precipitation for the area, the period of our study occurred during a dry winter. During dry periods, perhaps AWS provide resources to rodents related to moisture.