Habitat type impacts small mammal diversity in the Ukaguru Mountains, Tanzania

We assessed the habitat association of the diversity and abundance of small mammals in the Ukaguru Mountains within the Eastern Arc Mountains, Tanzania. An estimation of the vegetation parameters and live-trapping of small mammals for three consecutive nights per month for 21 months were carried out in farmland, disturbed and intact forests. A total of 1196 individual small mammals comprising 13 species were captured. Species diversity and evenness in intact forest were much higher compared to disturbed forest. Principal component analysis (PCA) explained 87.7% of the variance with two factors. The study suggests vegetation and habitat disturbances are factors responsible for the observed diversity of small mammals in the Ukaguru Mountains. Mastomys natalensis, Mus triton and Praomys delectorum accounted for 90.0% of total captures. M. triton and M. natalensis were the most abundant in farmland with 46.8 and 42.8% of total captures respectively and associated with the herbaceous vegetation. P. delectorum correlated with litter depth and trees and accounted for 90.0 and 80.0% total captures in disturbed and intact forests respectively but the mean abundances in both habitats were not significantly different (p = 0.72).

Habitat disturbance Linked with Host Microbiome Dispersion and Bd Dynamics in Temperate Amphibians

Anthropogenic habitat disturbances can dramatically alter ecological community interactions, including host-pathogen dynamics. Recent work has highlighted the potential for habitat disturbances to alter host-associated microbial communities, but the associations between anthropogenic disturbance, host microbiomes, and pathogens are unresolved. Amphibian skin microbial communities are particularly responsive to factors like temperature, physiochemistry, pathogen infection, and environmental microbial reservoirs. Through a field survey on wild populations of Acris crepitans (Hylidae) and Lithobates catesbeianus (Ranidae), we assessed effects of habitat disturbance on environmental bacterial resevoirs, Batrachochytrium dendrobatidis (Bd) infection, and skin microbiome composition. We found higher measures of microbiome dispersion (a measure of community stability) in A. crepitans from more disturbed ponds, supporting the hypothesis that disturbance increases stochasticity in biological communties. We also found that habitat disturbance limited microbiome similarity between locations for both species, suggesting less bacterial exchange in more disturbed areas. Higher disturbance was associated with lower Bd prevalence for A. crepitans, which could signify suboptimal microclimates for Bd in disturbed habitats. In this system we use microbiome dispersion as a metric of population health. Combined, our findings show that reduced microbiome stability stemming from habitat disturbance could compromise population health, even in the absence of pathogenic infection.

Disturbance Effects on Spatial Autocorrelation in Biodiversity: An Overview and a Call for Study

The spatially autocorrelated patterns of biodiversity can be an important determinant of ecological processes, functions and delivery of services across spatial scales. Therefore, understanding disturbance effects on spatial autocorrelation in biodiversity is crucial for conservation and restoration planning but remains unclear. In a survey of disturbance versus spatial patterns of biodiversity literature from forests, grasslands and savannah ecosystems, we found that habitat disturbances generally reduce the spatial autocorrelation in species diversity on average by 15.5% and reduce its range (the distance up to which autocorrelation prevails) by 21.4%, in part, due to disturbance-driven changes in environmental conditions, dispersal, species interactions, or a combination of these processes. The observed effect of disturbance, however, varied markedly among the scale of disturbance (patch-scale versus habitat-scale). Surprisingly, few studies have examined disturbance effects on the spatial patterns of functional diversity, and the overall effect was non-significant. Despite major knowledge gaps in certain areas, our analysis offers a much-needed initial insights into the disturbance-driven changes in the spatial patterns of biodiversity, thereby setting the ground for informed discussion on conservation and promotion of spatial heterogeneity in managing natural systems under a changing world.

Rapid reassembly of an intertidal community following prehistoric disturbance

The elimination of lower trophic levels following severe habitat disturbance can trigger new community assembly processes. However, little is known about how past habitat disturbances have affected codependent evolution of trophically-linked and closely interacting taxa. Using genome-wide analysis of a macroalgal community affected by ancient catastrophic coastal uplift, we track the ecological dynamics of past co-dispersal and co-diversification among obligate interacting taxa. Our study reveals rapid and concerted reassembly of an intertidal community following disturbance. Specifically, hierarchical co-demographic analyses of multispecies genomic data support synchronous expansions of four strictly intertidal species in the wake of tectonic disturbance. These data show that tight algal-epifaunal links underpin parallel demographic responses across distinct trophic levels. These results highlight that high-resolution comparative genomic data can elucidate the strength of obligate ecological interactions, and the evolutionary dynamics of past co-dispersal and co-diversification in post-disturbance communities.

In euglossine we trust as ecological indicators: a reply to Añino et al. (2019)

Orchid bees have been considered as good ecological indicators of habitat disturbances but recently Añino et al. (2019. Sociobiology, 66: 194-197) highlighted reasons why Euglossini role as indicators should be reevaluated. Despite agreeing with some points raised by them, we present an alternative view for the use of orchid bees as indicators. For us, the main problematic issues are: (i) the authors do not present a clear definition of ecological indicator, including its role as an indirect measure of biota response to disturbed environments; (ii) they do not properly acknowledge the relative good taxonomic status of orchid bees when compared with the remaining bees; (iii) and they do not distinguish the use of particular Euglossini species as indicators in certain circumstances. In spite of some knowledge gaps, we argue that Euglossini is a good candidate to be ecological indicators in tropical forests, maybe the best candidate among all the bees.

Overview of the impact of forest habitats quality and landscape disturbances on the ecology and conservation of dormice species

Arboreal mammals are a group of special concern. We reviewed the available literature to summarize the overall potential effects of forest habitat disturbances on dormice ecology and population parameters. We took into consideration the influence of forest structure, area size and fragmentation, vegetation biodiversity, forestry treatments, and the development of road networks. The vast majority of studies have only examined two species, hazel and edible dormouse, while the ecological requirements and conservation priorities of forest, garden, and Japanese dormice have rarely been studied. There has been a substantial increase in the number of dormice studies; however, many aspects of their ecology are still unknown. The current state of knowledge points to the essential role of the complex vertical structure of forest vegetation in providing arboreal movement corridors and safe nesting places for dormice species. Moreover, dormice species are cavity dwellers that depend on the presence of old trees and nest boxes, which could have ambiguous effects.

Development of microsatellite loci and population genetics of the catfish Pimelodus yuma (Siluriformes: Pimelodidae)

ABSTRACT Pimelodus yuma (formerly Pimelodus blochii) is a freshwater fish, endemic to the Colombian Magdalena-Cauca and Caribbean basins that experiences habitat disturbances resulting from anthropogenic activities. Due to the lack of information about the population genetics of this species, this study developed 14 species-specific microsatellite loci to assess the genetic diversity and population structure of samples from the lower section of the Cauca River. The studied species showed genetic diversity levels higher than the average values reported for Neotropical Siluriformes and significant inbreeding levels as was described for some congeners. Furthermore, P. yuma comprises two coexisting genetic groups that exhibit gene flow along the lower section of the Cauca River. This information constitutes a baseline for future monitoring of the genetic diversity and population structure in an anthropic influenced sector of the Magdalena-Cauca basin.

Reproductive effort of intertidal tropical seagrass as an indicator of habitat disturbance

Habitat disturbance is one of the major causes of seagrass loss around the Andaman Sea in the Indian Ocean bioregion. Assessing the seagrass response to these disturbances is of utmost importance in planning effective conservation measures. Here we report about seagrass reproductive effort (RE) as an indicator to assess seagrass response to habitat disturbances. Quadrat sampling was used to collect seagrass samples at three locations (a disturbed and undisturbed site per location) of the Andaman and Nicobar Islands. The health of seagrass meadows was quantified based on density-biomass indices of the disturbed sites. A change ratio (D/U) was derived by contrasting the RE of disturbed (D) sites with the undisturbed (U) sites of all three locations. The relationship between RE and plant morphometrics were also quantified. Reproductive density of T. hemprichii was higher and significant at the three disturbed sites. The average reproductive density of T. hemprichii at the disturbed sites was 3.3-fold higher than the undisturbed sites. The reproductive density consisted around 52% of the total shoot density of T. hemprichii at the disturbed sites. In general, the increase in the plant RE was site-specific and was 4-fold higher at the three disturbed sites. Positive and significant correlations was observed between the change ratio of RE and the plant morphometrics, suggesting an active participation of seagrass morphometrics in the reproductive process. Increase in seagrass RE can contribute to the increase in population genetic diversity, meadow maintenance and various ecosystem functions under the influence of anthropogenic disturbance scenarios.