Multiple Response Permutation Procedure Research Articles

Monitoring Changes in Composition and Diversity of Forest Vegetation Layers after the Cessation of Management for Renaturalization

Overstory and understory vegetation play a vital role in forest ecosystem functionality. However, it is necessary to enhance the knowledge of their diversity and compositional dynamics following cessation of disturbance, which is required to inform restoration approaches and the mechanisms required for maintaining disturbance cessation. We conducted a chronosequence spanning 0–1, 5–6, 11–12, 20–24, and 28–34 years since disturbance cessation, and old-growth forests to investigate the dynamic changes in overstory and understory vegetation diversity and composition, as well as maintenance mechanisms following the cessation of anthropogenic disturbances in subtropical regions of Eastern China. The current study results indicated a decrease in understory cover and periodic fluctuations in the diversity of overstorey and understory vegetation following disturbance cessation efforts. Specifically, the shrub layer exhibited the highest richness in 28–34 years, while the herb layer showed the lowest evenness. Multivariate analysis using multiple-response permutation procedures indicated that the species composition and interspecific quantity ratio of understory plants in the forest at 28–34 years significantly differ from those in the early closure stage. An indicator species analysis revealed that more support was given to sun-loving plants after 0–1 years of the enclosure, while species with shade tolerance and low nutrient requirements were supported after 28–34 years. The structural equation model results show that 38.8% of the impact on herb evenness was related to light and substrate diversity. The ecological restoration time mainly indirectly affects understory vegetation by influencing the upper vegetation, light availability, and substrate heterogeneity. Overall, this study revealed that cessation of anthropogenic disturbance can maintain and care for understorey plant diversity and contribute to the sustainable management of forests.

Amplicon-based next-generation sequencing for comparative analysis of root canal microbiome of teeth with primary and persistent/secondary endodontic infections.

To compare the root canal microbiome profiles of primary and persistent/secondary infections using high-throughput sequencing with the help of a reliable bioinformatics algorithm. Root canal samples of 10 teeth in the primary endodontic infection (PEI) group and 10 teeth in the persistent/secondary endodontic infection (SEI) group were included resulting in a total of 20 samples. After DNA extraction from the samples, sequencing was performed on the Illumina MiSeq platform. Pair-end Illumina reads were imported to QIIME 2; amplicon sequence variants (ASVs) generated by DADA2 were mapped to GreenGenes database. Weighted UniFrac distances were calculated and principal coordinates analysis (PCoA) was used to compare beta diversity patterns. The multiple response permutation procedure (MRPP), the analysis of similarities (ANOSIM), and permutational multivariate analysis of variance (adonis) were conducted for testing group differences. Linear discriminant analysis effect size (LEfSe) analysis was utilized to identify differentially abundant taxa between the groups. The linear discriminant analysis (LDA) score threshold was set to 4.0. Within the Gram-negative facultative anaerobic Gammaproteobacteria class outgroup, two orders (Pasteurellales, Vibrionales) and two families (Pasteurellaceae, Vibrionaceae) were significantly more abundant in the PEI group, whereas Gram-positive bacteria, Actinomycetales order, and Gram-positive anaerobic taxa, one genus (Olsenella) and one species (Olsenella uli), were identified as significantly more abundant in the SEI group. A few taxa were differentially abundant within either the PEI or SEI group. Reliable bioinformatic tools are needed to define microbial profiles of endodontic infections. Based on a limited number of samples, no distinct variation was determined between the bacterial diversity of initial and recurrent endodontic infections.

High Daily and Year-Round Variability in Denitrification and Nitrogen Fixation in a Northern Temperate River

Rates of nitrogen (N) cycling processes like denitrification and dinitrogen (N2) fixation, which together are the primary contributors to N2 flux rates from surface waters, may change at different time scales from seasons to weeks to days. Yet, we know little about the magnitude, mechanisms or drivers of these temporal changes, especially at shorter daily and weekly timescales. Quantifying variation in rates and drivers across temporal scales is essential to understand how nutrient cycling processes operate in aquatic ecosystems and predict how they may respond to shifting seasonal dynamics caused by global change (i.e., earlier snowmelt and extreme weather events). This study quantified denitrification and N2 fixation rates seasonally and daily in a northern temperate river, and explored how environmental conditions such as discharge, light, and N and phosphorus (P) concentrations were related to that variation at different time scales. We measured denitrification and N2 fixation rates on biweekly and daily intervals at a single 20-m long sampling reach in the Pilgrim River in Michigan's Upper Peninsula from May 2017 through May 2019. We found high rates of daily change (difference in rate from one day to the next) for both processes in all seasons (maximum daily change 5,690 μg N/m2/h for denitrification and 38 μg N/m2/h for N2 fixation). No detectable differences in rates among seasons were detected using Multiple Response Permutation Procedure (MRPP). Day-to-day variation did not change before and after elevated discharge events, including a 1,000-year flood that occurred in June 2018. Partial least squares (PLS) regression identified total dissolved N, dissolved organic N, and ammonium as important predictors of denitrification and N2 fixation, but explained only 15–28% of the variation in all measured rates. The unexpectedly high daily variation and lack of seasonal difference in rates found in this study demonstrate the need to use caution when studying these processes and/or extrapolating rates across time scales, as discrete and infrequent measurements may be misleading.

Maine's Bumble Bee (Hymenoptera: Apidae) Assemblage-Part 1: Composition, Seasonal and Regional Distribution, and Resource Use.

Global declines of bumble bees place natural and agricultural ecosystems at risk. Given bumble bees importance to Maine's major agricultural crops, we conducted a statewide, quantitative survey of bumble bee species seasonal and ecoregional abundance, richness, diversity, and floral resource use. We recorded 11 Bombus species at 40 survey sites across Maine's three ecoregions, with Bombus ternarius Cresson, 1863 and Bombus impatiens Cresson, 1863 being the most common and Bombus citrinus Smith, 1854 the least commonly encountered. Bumble bee species richness did not differ as a function of ecoregion, but did decline over the season, while species diversity differed by ecoregion and also declined over the season. Multiple response permutation procedure (MRPP) indicated ecoregional differences in species composition of bumble bee assemblages and nonmetric multidimensional scaling produced a stable ordination suggesting assemblage differences were associated with survey site variables including forage plant cover, forage plant richness, elevation, development, and deciduous forest cover. Both MRPP and correspondence analysis also revealed differences in the floral resources utilized by bumble bee species in each ecoregion. Low connectance and nestedness levels indicated low stability pollinator networks in each ecoregion, suggesting Maine bumble bee assemblages may be at risk of decline in response to additional external perturbations.

Restoration in degraded subtropical broadleaved forests induces changes in soil bacterial communities

Soil resident bacterial communities are involved in myriad key processes that facilitate ecosystem functionality. However, our understanding of their diversity and compositional dynamics following ecological restoration, and the main factors that influence them, remains inadequate. We employed a chronosequence (0–1, 5–6, 11–12, 20–24, and 28–34 years since restoration) to examine the dynamic changes in soil bacterial diversity and composition, as well as the essential factors that affected them since the cessation of anthropogenic disturbances (e.g., recurring fuelwood collection and domestic animal grazing), and used old-growth forests as a reference in the subtropical forests of Eastern China. We found that soil bacterial diversity increased with time since restoration, and community compositions shifted toward being similar to those of old-growth forests over time. However, the recovery process was prolonged since the significant difference in soil bacterial diversity between degraded and restored forests did not occur until after 24 years since restoration. Multivariate analysis using multiple-response permutation procedures indicated the soil bacterial communities were compositionally distinct between degraded, restored, and old-growth forests. An analysis of indicator species revealed that forests at the early stage of recovery times supported Rokubacteria and Actinobacteria, while old-growth forests were distinguished by Chlamydiae. Soil carbon, microbial biomass carbon, soil water content, and microbial biomass nitrogen recovered over time and became increasingly akin to those of old-growth forest soils. Soil carbon, soil water content, and soil pH could explain 84.5% of the variations in bacterial community dynamics following restoration. Overall, this study revealed a prolonged recovery process of the community structures of soil bacteria (e.g., diversity, composition, and phylum abundance) following restoration, which was coupled with changes in soil properties in subtropical forests of China.

Artificial light at night at the terrestrial-aquatic interface: Effects on predators and fluxes of insect prey.

The outcomes of species interactions–such as those between predators and prey–increasingly depend on environmental conditions that are modified by human activities. Light is among the most fundamental environmental parameters, and humans have dramatically altered natural light regimes across much of the globe through the addition of artificial light at night (ALAN). The consequences for species interactions, communities and ecosystems are just beginning to be understood. Here we present findings from a replicated field experiment that simulated over-the-water lighting in the littoral zone of a small lake. We evaluated responses by emergent aquatic insects and terrestrial invertebrate communities, and riparian predators (tetragnathid spiders). On average ALAN plots had 51% more spiders than control plots that were not illuminated. Mean individual spider body mass was greater in ALAN plots relative to controls, an effect that was strongly sex-dependent; mean male body mass was 34% greater in ALAN plots while female body mass was 176% greater. The average number of prey items captured in spider webs was 139% greater on ALAN mesocosms, an effect attributed to emergent aquatic insects. Non-metric multidimensional scaling and a multiple response permutation procedure revealed significantly different invertebrate communities captured in pan traps positioned in ALAN plots and controls. Control plots had taxonomic-diversity values (as H’) that were 58% greater than ALAN plots, and communities that were 83% more-even. We attribute these differences to the aquatic family Caenidae which was the dominant family across both light treatments, but was 818% more abundant in ALAN plots. Our findings show that when ALAN is located in close proximity to freshwater it can concentrate fluxes of emergent aquatic insects, and that terrestrial predators in the littoral zone can compound this effect and intercept resource flows, preventing them from entering the terrestrial realm.

How bottom-up and top-down controls shape dune topographic variability along the U.S. Virginia barrier island coast and the inference of dune dynamical properties

When topography is incorporated into models of barrier dune dynamical states, how it is represented determines the dynamical properties inferred. Bottom-up representations rely on elevation and localized biogeomorphic modification. Top-down representations incorporate constraints imposed by the spatial patterns of topography. These spatial patterns emerge from island morphological context and the extent localized biogeomorphic processes can expand and structure the larger landscape. We compared topographies across 30 sites among seven barrier islands of the Virginia (U.S.A) coast to gauge the importance of elevation, the bottom-up variable often weighted most in dune biogeomorphic models, relative to top-down patch and continuous surface landscape representations of topography. LiDAR-derived digital elevation models of each site were characterized with non-metric multidimensional scaling to assess how these bottom-up and top-down metrics structured dune topographic variability. Multiple response permutation procedures gauged the strength of topographic differences among sites grouped according to island morphology versus groupings defined by clustering of topographic metrics. Elevation was the dominant metric structuring topography for these low relief islands. Spatial structure was weakly developed. Topographic differences were more robust when based on clusters defined largely by elevational properties rather than by island or island morphological type. For the Virginia barrier islands, storm inputs may more directly shape topography and override landscape-extent top-down spatial structure. The dominance of elevation suggests that resistance may be the more relevant dynamical property for this coast. Properties like resilience may be greater on higher islands with longer storm-free intervals in which biogeomorphic elements can configure relief and act as recursive top-down controls.

Impacto del sistema zanja bordo sobre la cobertura vegetal en pastizales de la región Mixteca, estado de Oaxaca.

In Mexico, the foraging-stock load in pastures is not regulated according to stocking rates, which are estimated in terms of coverage and productivity; this situation has led to the degradation of the vegetation coverage, the reduction of infiltration and water storage capacity in the soil, and the increase of surface runoffs and erosion, which affect the pasture productivity and biomass production, and promote the proliferation of plants with lower palatability and protein quality. Actions to endorse the conservation of soil and water have been implemented in order to mitigate grassland degradation. In this research, the impact of the ditch check dam (DCD) system over the vegetation coverage was evaluated in grasslands of the watershed from rancho Dolores, in the Mixteca region of the State of Oaxaca. Changes in the vegetation coverage were estimated according to percentages of green, dry and total coverage, biomass production, vegetation indexes, and floristic composition in three polygons with DCD at five sampling sites (among-ditch, starting point, ditch, check dam, and foot) and in three polygons without DCD at three sampling sites (upper, central and lower portions). Biomass production in the check dam and ditch was 2.38 Mg ha-1 and 2.29 Mg ha-1 respectively, with significant differences among the following sites: among-ditch, starting point, and foot; the percentages of vegetation coverage, IVPN, NDVI and SAVI did not show significant differences. The control presented significant differences in biomass production and coverage percentage; however, the vegetation indexes did not vary. In areas with DCD, the dominant species was Melinis repens with low forage potential; in control areas, the dominant species was Bouteloua griff ithsii, with regular forage potential. The Multiple Response Permutation Procedure indicated significant differences in the floristic composition among sites with DCD and the control.

Using the Rosgen Stream Classification System to Aid in Riparian Complex Ecological Site Descriptions Development

Land managers need consistent terminology and classification frameworks to discuss the ecological status of the land. A common framework used in upland terrestrial systems is an ecological site description (ESD), in which systems are categorized by soils, vegetation, and topography. Creating ESDs in riparian areas must follow a different framework than upland systems because function of riparian systems is driven by hydrology. This study categorized riparian areas by hydrology using stream geomorphology and the Rosgen Stream Classification System. Stream cross sectional and longitudinal profile data were collected from 75 reaches from 19 streams in North Dakota from 2012 to 2018. Each reach (i.e., one full meander) was classified by channel type (E, C, B, F, and G), and stability class (stable and unstable). A stream parameter matrix was constructed using entrenchment ratio, width-to-depth ratio, sinuosity, slope, channel bed material, bank height ratio, and meander width ratio. A multiple response permutation procedure showed that the parameters differed on the basis of both channel type and stability class. An indicator analysis showed that entrenchment ratio, bank height ratio, and meander width ratio were the parameters most influential in separating the reaches by stability class. The strongest indicator stable reach was entrenchment ratio, but meander width ratio and bank height ratio were also significant indicators of stable and unstable reaches, respectively. The parameters used in this study to delineate channel type can be used to consistently discriminate between stable and unstable channels. This information may be a useful tool in describing the states and transitions of prairie stream development in riparian complex ESDs, validating the continued use of Rosgen Stream Classification System in ESD development.

Nematode communities differ in Hopi landrace maize and commercial maize

Selection pressures of crop breeding in varying abiotic contexts may produce cultivars differing in their relationships with belowground organisms. Nematode assemblages associated with a Hopi maize (Zea mays L.) landrace and two commercial maize varieties were examined at three traditional farms (two irrigated, one dry-farmed) near the village of Moenkopi on the Hopi Reservation in Arizona, U.S.A. At each farm, the landrace and one commercial maize variety were cultivated in close proximity. Within the two irrigated farms, densities of free-living nematodes, but not plant parasitic nematodes, were higher in landrace plots compared to commercial variety plots; however, at the dry-farmed site the nematode assemblages associated with the two maize varieties did not differ. Nonmetric multidimensional scaling (NMDS) and multiple response permutation procedure (MRPP) showed that at the irrigated farms, nematode assemblages associated with landrace maize differed significantly from those associated with commercial maize in analyses based on functional guilds, feeding groups and non-phytoparasitic c-p groups. Assemblages at the dry-farmed site were different from those at the irrigated sites in community composition based on morphotypes, functional guilds, and feeding groups, but were similar to the irrigated commercial variety plots based on c-p groups. Nematode abundances were likely constrained by water availability at the dry-farmed site, but at the irrigated sites, nematode community dissimilarities between the landrace and the commercial maize variety may have resulted from differences in plant-soil microbe interactions for the two crop varieties. Selection pressures associated with Hopi agroecosystems might have produced landraces with different belowground allocation strategies than commercial crop varieties selected under high resource conditions.

Models of the fine-scale spatial distributions of trees in managed and unmanaged forest patches with Abies alba Mill. and Fagus sylvatica L.

Fine-scale spatial point-pattern analysis can give insights into the underlying pattern-creating biological processes in an environmental context. However, there are few studies comparing the spatial distribution of trees in managed stands and unmanaged forests that take into account their developmental stage. The main aim of this study was to assess and model the spatial patterns of Abies alba Mill. and Fagus sylvatica L. trees in managed and unmanaged forest patches in the early developmental stage.This study investigated tree communities dominated by A. alba and F. sylvatica in the Świętokrzyskie Mountains in Central Europe. From 2016 to 2018, 60 sample plots representing the growing-up developmental stage were randomly selected: 30 from managed stands and 30 from unmanaged forests. Models of the fine-scale spatial distributions of the trees were distinguished using hierarchical cluster analysis (HCA), analysis of group similarities (ANOSIM), and multiple response permutation procedures (MRPP). Indices based on the K-function and the O-ring statistic, ILr and IOr, respectively, were developed and used as clustering variables. The proposed indices assume values from −1 to 1 for random patterns; values > 1 indicate aggregation, and values < −1 indicate regularity.Models of the fine-scale spatial distributions of the trees differed only slightly between the managed and unmanaged patches. These models suggest that in the investigated sample plots, the fine-scale spatial patterns (with distances among the trees not exceeding 10 m) were usually random. Only in a few patches were the tree distributions found to be aggregated, from 5 to 10 m and from 7 to 10 m in the managed stands and the unmanaged forests, respectively. The relatively similar models of the fine-scale spatial distributions of the trees in the managed and unmanaged forest patches in the growing-up developmental stage show that early successional forest dynamics follow a parallel trajectory of recovery. The long-term application of the shelterwood system as well as self-regeneration and self-regulation natural processes led to the creation of the similar spatial structures of the trees. This observation may be helpful in the design of planting patterns and/or harvesting schedules.

The Effects of Area and Habitat Heterogeneity on Bird Richness and Composition in High Elevation Wetlands (“Bofedales”) of the Central Andes of Peru

We assessed area and habitat heterogeneity effects on avian richness and composition in bofedales that differed in size and microhabitat diversity. We analyzed data collected in 2 seasons and 24 bofedales using General Linear Models, Ordinary Least Square models to establish the relationship of predictor variables on richness and Akaike Information Criterion for model selection. We evaluate composition classifying species into groups using Bray Curtis ordination, followed by Multiple Response Permutation Procedure to test for differences among groups, and Indicator Species Analysis to identify species. Bofedales differed in richness (F = 5.1, p 0.05). The best model indicates that 54% of variance in richness was explained by area and microhabitat diversity, however, a tendency to decrease in microhabitat diversity as area increases, suggests a relatively more important role of area. Results are supported by composition, as microhabitats not only differed pairwise (T = −94.14, A = 0.601, p < 0.001) and had significant indicator species (p < 0.05), but because its differential contribution to richness, as some microhabitats were more speciose than others. As such, few species-rich microhabitats may contribute more to richness than many species-poor ones which is not predicted by the habitat heterogeneity hypothesis. Disentangling the influence of area and habitat heterogeneity on species richness is important to establish conservation priorities that ensure bofedales integrity under imminent climate change.

Correlates of Northern Bobwhite Distribution and Abundance with Land-Use Characteristics in Kansas

County-level agricultural statistics were correlated with Rural Mail Carrier Survey reports and Breeding Bird Survey data for northern bobwhite (Colinus virginianus) in Kansas. Results indicate statewide analysis is feasible when temporally congruent data exist for both agricultural land-use characteristics and bobwhite distribution and abundance. Interpretations of these results can be useful in state or regional analysis and in the development of habitat management strategies for bobwhite. The Multiple Response Permutation Procedure identified 16 land-use variables, 3 soil variables, and 1 spatial variable that were significantly different in counties where bobwhite were present from counties where they were absent. Sixteen land-use variables, 5 soil variables, and 3 spatial variables distinguished between counties where bobwhite abundance was classified as high or low. Spearman's rank correlation identified 8 soil variables, 14 land-use variables, and 3 spatial variables that were significantly correlated with bobwhite abundance. Least absolute deviation regression analysis revealed 4 land-use variables that were significantly correlated (Agreement= 0.48, P = 0.0001) with bobwhite abundance.

Two orchids, one scent? Floral volatiles of Catasetum cernuum and Gongora bufonia suggest convergent evolution to a unique pollination niche

Floral volatile organic compounds (VOCs) are important signals in plant-pollinator communication and thus subjected to olfactory-mediated selection. Occasionally, phylogenetically unrelated plant species will converge towards similar patterns of floral scent signalling to harness pollinators, representing a common adaptive pollination niche. Catasetum cernuum and Gongora bufonia, epiphytic orchids that are native to the Atlantic Forest of southeastern South America, are exclusively pollinated by male Eufriesea violacea orchid-bees; we hypothesised that the two species have converged towards similar floral scent compositions to effectively attract these particular fragrance-seeking floral visitors. The similarity of the chemical composition of floral scent samples obtained through headspace collection was tested using multiple approaches of multivariate analyses (Multiple Response Permutation Procedure—MRPP). According to MRPP, floral scents of C. cernuum and G. bufonia are significantly different. Additionally, the floral scents of C. cernuum and G. bufonia present (E)-β-ocimene and (E)-epoxyocimene as their major compounds, respectively. (E)-β-ocimene is a common constituent of floral scents from euglossine-pollinated orchids, while (E)-epoxyocimene is quite rare in orchids’ floral scents and it is found in only a few other species which occur outside the distribution range of C. cernuum, G. bufonia and E. violacea. However, 12 out of the 34 identified VOCs, including (E)-β-ocimene and (E)-epoxyocimene, are shared between both species. Therefore, we assume that both (E)-β-ocimene and (E)-epoxyocimene, either alone or mixed with other floral VOCs, play a major role in the specific association between these two orchids and their exclusive euglossine pollinator.

How many seasons are there in a sub-tropical lake? A multivariate statistical approach to determine seasonality and its application to phytoplankton dynamics

Seasonal patterns in factors that affect primary producers are an important part of defining the structure and function of aquatic ecosystems. However, defining seasonality is often more difficult in aquatic than in terrestrial ecosystems, particularly in subtropical and tropical environments. In this study, a long-term data set for a shallow subtropical lake (Lake George, Florida, USA) was used to investigate seasonality using a range of physical, chemical and hydrological parameters. K-means cluster analysis of monthly averages among 11 selected environmental factors across 18 years suggested the overall annual pattern consists of three different seasonal clusters: a cold season (January–April), a warm season (May–August) and a flushing season (September–December). High dissolved oxygen and increased Secchi depth are key features of the cold season, while the warm season is characterized by high mean light irradiances, temperature, rainfalls, total nitrogen and phytoplankton biomass (as chlorophyll a level). The flushing season is characterized by high river discharge rates and high levels of dissolved nutrients and colored organic matter. Multiple response permutation procedures indicated that these seasonal cluster arrangements were significantly different than randomly permuted clusters (A-statistics = 0.3314, significance of delta = 0.0160, based on 1000 permutations). Results from principal component analyses supported the presence of the three seasons in the lake. Linear models explaining chlorophyll a levels using the 3-season system generally indicated better ratios of explained variance compared to the models without seasonal alignments, further indicating that even for sub-tropical systems defining seasons provides a better understanding of phytoplankton dynamics. The approaches used in this study provide statistically-based multivariate tools for the definition of seasonality in aquatic ecosystems. The ability to accurately define seasons is a key step in modeling the structure and dynamics of aquatic ecosystem, which is essential to the development of effective management strategies in a rapidly changing world.

The Relationship between Soil Chemistry and the Occurrence ofEchinacea laevigatain Northeast Georgia

ABSTRACT Echinacea laevigata, or smooth coneflower, is a federally listed endangered species found in open woods and human maintained clearings, including roadsides and utility rights of way. The species is disjunctly distributed in the eastern United States, with populations in Virginia, North Carolina, South Carolina, and Georgia, where they are associated with calcium and magnesium rich soils. This research was designed to determine if there is a nonrandom relationship between soil chemistry and the occurrence of E. laevigata along roadsides in northeast Georgia. Soil samples were collected from sites along roadsides with known populations and from arbitrarily selected sites without E. laevigata along the same roadsides. Multiple response permutation procedure (MRPP) found a nonrandom relationship between soil chemistry and occurrence. Sites with E. laevigata had a wider range of pH values but had lower iron values than the set of arbitrarily selected sites, suggesting that the species may be excluded ...

Avian Communities of the Northern Mackenzie Mountains, Northwest Territories, Canada

Basic knowledge of the abundance and distribution of birds and their habitats and the relationships between them is limited for many parts of Arctic Canada, including montane regions. This information is important for conservation purposes as bird populations and habitats shift and as interest in development of northern areas increases. We characterized bird communities in the Mackenzie Mountains of the Northwest Territories by conducting point counts (n = 376) in June 2009 and 2010 and using community analysis metrics (multiple response permutation procedures, indicator species analysis, non-metric multidimensional scaling) to statistically and graphically describe bird data in six habitat types: coniferous forest, deciduous forest, shrub (short and tall), alpine tundra, and open water wetlands. Distinct habitats had significantly different bird communities, as shown by using multiple response permutation procedures (p &lt; 0.005). Of 51 species, 32 had significant (p &lt; 0.05) indicator values for one habitat type (n = 15) or groups of habitats (n = 17) in an indicator species analysis. The tall shrub habitat type had the most indicator species (six species) followed by alpine tundra (five species), then the combined conifer, deciduous, and wetland habitat group (four species) and the deciduous forest habitat types (three species). Species richness was highest in the tall shrub (n = 37), alpine (n = 30), and conifer and short shrub (n = 29) habitats. We also observed eight bird species not previously known to occur in the area, or which were outside published ranges. Our results highlight the variability in bird community composition between the major habitat types in the Mackenzie Mountains, serve as a baseline for future bird studies in the region, and underscore the need for more research in the area with impending anthropogenic changes.

Concordance between vascular plant and macrofungal community composition in broadleaf deciduous forests in central Italy

Abstract: We examined the concordance between vascular plants and macrofungi (grouped into trophic groups) in Mediterranean forest habitats (central Italy). Our goal was to test how consistently plant and fungi groups classify plots in a broadleaf deciduous forest dominated by Quercus cerris. Our hypothesis was that groups of plants can be used as surrogates for the classification of macrofungal communities. The test of concordance comprised two steps: 1) the plant species data sets were subjected to cluster analysis, to obtain three classifications based on presence of all plants, presence and frequency of only woody species; 2) Multiple Response Permutation Procedures (MRPP) was used to test the performance of each plant classification applied to the fungi data sets. The sample scores along the first PCA axis was used to investigate the relationships between compositional patterns. In the concordance analysis, the classification of only woody plants provided better results than the classification obtained with herbaceous and woody plants together. Cross-tests gave the best results when the “woody plants” classification was applied to ectomycorrhizal fungi (EMF) and, to a certain extent, to humicolous saprotrophs (Sh). The ordination analysis indicated that the frequency of woody plants follows a similar spatial distribution to EMF and Sh fungal groups and is therefore expected to discriminate the same environmental gradients. Many EMF exhibit preferences for few (one or two) hosts. Significant associations were found among a greater number of EMF and woody plant species. Woody plants such as Sorbus domestica and Prunus spinosa appear to be associated with many EMF. The combination of a high frequency of Fraxinus oxycarpa and Quercus petraea seems to promote distinct assemblages of EMF and Sh fungi. Then, characteristic assemblages of fungi were found in association with certain tree and shrub combinations.

The assemblage composition and structure of swimming crabs (Portunoidea) in continental shelf waters of southeastern Brazil

Three regions along the Brazilian coast characterized by the occurrence of contrasting natural phenomena, such as upwellings and continental input, were surveyed to determine the composition and structure of the assemblage of swimming crabs. Twelve monthly collections were undertaken (July 2010 to June 2011) in Macaé, Rio de Janeiro (MAC); Ubatuba, São Paulo (UBA); and São Francisco do Sul, Santa Catarina (SFS). The lowest values ​​of the phi sediment grain size measure, bottom temperature and the highest values of organic matter and salinity were measured in MAC. In all, 10,686 individuals were collected, belonging to six species of Portunoidea: Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Callinectes sapidus, Achelous spinicarpus and Achelous spinimanus. A Multiple Response Permutation Procedure (MRPP) test indicated that the species composition differed significantly among the sampling sites, showing substantial heterogeneity in the composition and abundance of species among regions. The results suggest that C. danae was more abundant in waters with lower salinity and lower organic matter content. In contrast, A. spinimanus is positively correlated with these factors, showing a greater abundance under the opposite conditions. Callinectes ornatus appeared not to show strong selectivity for particular habitat characteristics. We conclude from these findings that areas affected by different phenomena produce changes in the composition and abundance of the assemblage of Portunoidea. Although the strength of eutrophication differs between UBA and MAC, the substantial continental inflow affecting SFS favors the development of species that complete their life cycle in the estuary.

Lichen community from an endangered forest under different management practices in central Argentina

We studied a lichen community from 300 ha of native Espinal forest under different types of management, classified into the following sectors: temporary grazing, adjacent crops, landscaped, and conserved. We observed 20 trees in each sector, identified lichen species and measured coverage in grids of 0.2 x 0.2 m. We compared alpha and beta diversity plus coverage by sector using the Kruskal-Wallis and Mann-Whitney U tests. We also applied a Multiple Response Permutation Procedure, a Non-metric Multidimensional Scaling multivariate analysis and the Indicator Species Analysis to test associations. We found 34 species of lichens. Physciaceae was the dominant family in the community. Total lichen coverage was highest in the temporary grazing sector and lowest in the conserved sector. No significant differences were found in alpha diversity among sectors; however, beta diversity was higher in the conserved sector. Multivariate analysis also showed that different management practices determine changes in community composition.