Intermediate levels of wood extraction may facilitate coexistence of an endemic arboreal marsupial and Indigenous communities

Land-use change is a major driver of biodiversity loss. Large-scale disturbances such as habitat loss, fragmentation and degradation are known to have negative consequences for native biota, but the effects of small-scale disturbances such as selective logging are less well known. We compared three sites with different regimes of selective logging performed by Indigenous communities in the South American temperate rainforest, to assess effects on the density and habitat selection patterns of the Near Threatened endemic arboreal marsupial Dromiciops gliroides. We used structured interviews to identify patterns of wood extraction, which was 0.22–2.55 m3 per ha per year. In the less disturbed site only two tree species were logged, in the intermediately disturbed sites eight species were logged at low intensity, and in the most disturbed site seven species were logged intensively. The site with intermediate disturbance had the highest fleshy-fruited plant diversity and fruit biomass values as a result of the proliferation of shade-intolerant plants. This site also had the highest density of D. gliroides. These findings are consistent with Connell's intermediate disturbance hypothesis, suggesting that coexistence of people with nature is possible if wood extraction volumes are moderate, increasing plant diversity. Indigenous communities have sustainably used natural resources for centuries, but current rates of land-use change are becoming a significant threat to both them and their natural resources.

Assessment and Valuation of Commercially Important Bivalves and Gastropods within the Seagrass Beds of Laguindingan, Misamis Oriental and Rizal, Zamboanga del Norte, Philippines

A study was conducted to assess the abundance and value of commercially important bivalves and gastropods within the seagrass beds of Laguindingan, Misamis Oriental and Rizal, Zamboanga del Norte, Mindanao, Philippines. The line transect method was used to assess the diversity of the bivalves and gastropods within the seagrass beds and coring was used in collecting sediment samples. Laguindingan was categorized as undisturbed site, while Rizal as disturbed site. The results identified three families of gastropods in undisturbed and thirteen families in disturbed, comprising a total of seven bivalves and six gastropods. Cyprea sp. Dominated in undisturbed area, while Anadara inequivalves dominated in disturbed area. The diversity index in disturbed (1.57) was greater than in undisturbed (0.88) probably due to high organic matter (2.56ppm) compared to the undisturbed area (1.92ppm). Ironically, the total volume of bivalves and gastropods production in disturbed area was higher at19.84 kg compared with2.23 kg in undisturbed. In terms of total monetary value, the undisturbed production could yield PHP 22,672.32 (USD 466.48) in an approximated area of 165 ha, while PHP 422,130.50 (USD 8,685.37) in 326 ha in the disturbed area. The study revealed that higher diversity resulted in higher production with greater monetary value derived from bivalves and gastropods in disturbed area contributed by higher organic load. Protection and management of the seagrass beds is likely most needed in both disturbed and undisturbed are as to support not only a robust but also a healthy production of shellfish fit for human consumption.

Clonal variation in coppiced and uncoppiced growth, root-sprout stem formation, and biomass partitioning in Salix interior on two highly disturbed site types

Salix interior Rowlee (INT), a wide-ranging North American willow from the small taxonomic group Salix sect. Longifoliae, is notable for its ability to form multi-stemmed vegetative stem colonies arising via root sprouts (RS) from a shallow horizontal root network. This study quantifies biomass production for both 1-yr-old coppiced plants and the original 4-yr-old plants, as well as for the RS stems associated with each ortet (original mother plant) using eight selected genotypes established on two distinct site types. Significantly greater coppiced and uncoppiced ortet stem dry mass was recorded on the coarse-textured, shale rock overburden (SO); possibly due to significantly greater fertility, compared to adjacent gravel outwash deposits (GD), which had greater RS stem mass. Significant clonal differences, as well as site type × clone interactions, were found for ortet stem dry mass, especially on SO sites, When expressed as a fraction of total stem dry mass produced on 2 m × 2 m biomass plots, the RS component represented a significant 57% of total stem dry mass per plot on GD sites. The use of colony-forming willows such as INT minimizes the need for periodic replanting, providing a cost advantage over conventional short-rotation, coppice-based woody biomass plantations using species that do not have the ability to reproduce via root sprouting.

Nematodes as bio-indicators of physical disturbance of marine sediments following polychaete bait harvesting

Sediment disturbance in marine environments is caused by activities including polychaete bait harvesting, trawling, dredging, sediment erosion and treading. These activities affect the benthic communities by changing the densities, community assemblage and diversity. The aim of this study was to evaluate the potential of nematodes as indicators of sediments disturbance following polychaete bait harvesting. The study was conducted in three sites experiencing different bait harvesting intensities in Mida Creek, Kenya. Sediment samples were collected from the mudflats during low tide, preserved in 5% formalin and transported to the laboratory for processing and identification of nematodes. The highly disturbed site recorded the lowest nematode genus richness while the less disturbed sites had the highest. Overall, the most abundant nematode genera in the non-disturbed (Dabaso) and less disturbed sites (Kirepwe) were selective deposit feeders (Spirinia and Terschellingia), while most disturbed sites (e.g. Mayonda) had predators/omnivores (Pheronus, Aporcelaimellus) and selected members of the genus Spirinia. The disturbed site was characterised by low nematode diversity (H’) and low dominance (D) while the non-disturbed and less disturbed sites had higher diversity and dominance. Clearly, nematode community assemblage, diversity and feeding guilds changed following disturbance to a low diversity that favoured higher proportions of predator/omnivore taxa.

Anthropogenic Pressure on Tree Species Diversity, Composition, and Growth of Balanites aegyptiaca in Dinder Biosphere Reserve, Sudan

Anthropogenic disturbances, such as illegal harvesting and livestock browsing, often affect natural forests. However, the resulting tree species diversity, composition, and population structure have rarely been quantified. We assessed tree species diversity and importance value indices and, in particular, Balanites aegyptiaca (L.) Del. population structure, across 100 sample plots of 25 m × 40 m in disturbed and non-disturbed sites at the Dinder Biosphere Reserve, Sudan, from April 2019 to April 2020. We found that the tree species diversity in non-disturbed sites was more than double that of disturbed sites (p < 0.001, T = 32.6), and seedlings and saplings comprised more than 72% of the entire tree population (F2,48 = 116.4, p = 0.034; F2,48 = 163.2, p = 0.021, respectively). The tree density of B. aegyptiaca in the disturbed site was less than half that of the non-disturbed site (p = 0.018, T = 2.6). Balanites aegyptiaca was seven times more aggregated in disturbed sites compared to more regularly spaced trees in non-disturbed sites (T = 39.3 and p < 0.001). The poor B. aegyptiaca population status of the disturbed site shows that the conservation of this vulnerable species is essential for a sustainable management and utilization scheme.

Contrary to vertebrates, less aggressive and more consistent individuals are common in disturbed habitats in the colonial spider Metabus gravidus (Araneae: Araneidae)

Habitat disturbance may affect average behavioural types and consistency/plasticity of behaviour. Studies with solitary vertebrates suggest that human-modified habitats may favour bolder, more aggressive and more plastic individuals. We evaluated whether wild colonial spiders, Metabus gravidus, vary in the magnitude, consistency and plasticity of boldness and aggressiveness between an undisturbed forest and an adjacent urban area in Monteverde, Costa Rica. Repeatability of aggressiveness was high at the disturbed site but moderate at the undisturbed site; repeatability of boldness was low at both sites. Individual and population plasticity was similar between sites for both behaviours. Aggressiveness decreases with increasing colony size at the disturbed site; this trend was not observed at the undisturbed site. Boldness did not change with colony size. In contrast to solitary animals, our results indicate that less aggressive and more consistent colonies may have an advantage living in human-disturbed habitats.

Anthropogenic disturbance and chimpanzee (Pan troglodytes) habitat use in the Masito-Ugalla Ecosystem, Tanzania

The habitat quality of chimpanzee (Pan troglodytes), including the availability of plant food and nesting species, is important to ensure the long-term survival of this endangered species. Botanical composition of vegetation is spatially variable and depends on soil characteristics, weather, topography, and numerous other biotic and abiotic factors. There are few data regarding the availability of chimpanzee plant food and nesting species in the Masito-Ugalla Ecosystem (MUE), a vast area that lies outside national park boundaries in Tanzania, and how the availability of these resources varies with human disturbance. We hypothesized that chimpanzee plant food species richness, diversity, and abundance decline with increasing human disturbance. Further, we predicted that chimpanzee abundance and habitat use is influenced negatively by human disturbance. Published literature from Issa Valley, Gombe, and Mahale Mountains National Parks, in Tanzania, was used to document plant species consumed by chimpanzees, and quantify their richness, diversity, and abundance, along 32 transects totaling 63.8 km in length across four sites of varying human disturbance in MUE. We documented 102 chimpanzee plant food species and found a significant differences in their species richness (H = 55.09, P &lt; 0.001) and diversity (H = 36.81, P &lt; 0.001) across disturbance levels, with the moderately disturbed site exhibiting the highest species richness and diversity. Chimpanzees built nests in 17 different tree species. The abundance of nesting tree species did not vary across survey sites (H = 0.279, P &gt; 0.964). The least disturbed site exhibited the highest encounter rate of chimpanzee nests/km, with rates declining toward the highly disturbed sites. Our results show that severe anthropogenic disturbance in MUE is associated with the loss of chimpanzee plant food species and negatively influences chimpanzee habitat use, a relationship that threatens the future of all chimpanzee populations outside national parks.

Taxonomic, Phylogenetic, and Functional Diversity of Ferns at Three Differently Disturbed Sites in Longnan County, China

Human disturbances are greatly threatening to the biodiversity of vascular plants. Compared to seed plants, the diversity patterns of ferns have been poorly studied along disturbance gradients, including aspects of their taxonomic, phylogenetic, and functional diversity. Longnan County, a biodiversity hotspot in the subtropical zone in South China, was selected to obtain a more thorough picture of the fern–disturbance relationship, in particular, the taxonomic, phylogenetic, and functional diversity of ferns at different levels of disturbance. In 90 sample plots of 5 × 5 m2 along roadsides at three sites, we recorded a total of 20 families, 50 genera, and 99 species of ferns, as well as 9759 individual ferns. The sample coverage curve indicated that the sampling effort was sufficient for biodiversity analysis. In general, the taxonomic, phylogenetic, and functional diversity measured by Hill numbers of order q = 0–3 indicated that the fern diversity in Longnan County was largely influenced by the level of human disturbance, which supports the ‘increasing disturbance hypothesis’. Many functional traits of ferns at the most disturbed site were adaptive to the disturbance. There were also some indicators of fern species responding to the different disturbance levels. Hence, ferns may be considered as a good indicator group for environmental stress.

Bioassessment of Mandakini River with the help of aquatic macroinvertebrates in the vicinity of Kedarnath Wildlife Sanctuary

Increasing advancement in development activities in the Indian Himalayan region in tandem with changing climate is influencing the ecological patterns of rivers. Thus, the present study investigates the effect of various degrees of anthropogenic stresses and possible implication of thermal dynamics of river water on the macroinvertebrate community in the Mandakini River, which flows in the vicinity of Kedarnath Wildlife Sanctuary of Chamoli district, Uttarakhand. The main objective was to study the community structure of macroinvertebrates in the Mandakini River and to calculate the effect of anthropogenic stresses on the macroinvertebrate community, particularly on Ephemeroptera, Plecoptera, and Trichoptera. The study was carried out in 10 spatially located sampling stations, and the frequency of sampling was divided into pre- and post-monsoon season (May and November 2017). Based on the degree of anthropogenic stresses, sampling locations were divided into least (Sonprayag), medium (Ukhimath), and high disturbed (Rudraprayag) sites. A total of 3257 individuals belonging to 7 orders and 21 families were found in both the sampling season. Diptera and Trichoptera were dominant orders in both the seasons, whereas Baetidae (Ephemeroptera), Hydropsychidae, Leptoceridae (Trichoptera) and Chironomidae (Diptera) were dominant families. Shannon diversity index varies from 2.048 to 2.25 in the least disturbed site (Sonprayag), 0.186–2.446 in medium disturbance (Ukhimath), and 1.362–2.271 in the highly disturbed site (Rudraprayag) in both the sampling season. Quantification of the EPT index shows a negative trend with an increase in anthropogenic stress, and it was least in Rudraprayag as compared to the other two sites. Result of one-way ANOVA shows a significant difference in diversity between pre- and post-monsoon season (p < 0.05). Analyzing the research gaps, it is recommended to have long-term ecological monitoring of high altitude and glacier-fed rivers and streams to obtain robust information regarding the dynamics of the riverine ecosystem in Garhwal Himalayas.

Combining genotype, phenotype, and environmental data to delineate site-adjusted provenance strategies for ecological restoration

Despite the importance of climate-adjusted provenancing to mitigate the effects of environmental change, climatic considerations alone are insufficient when restoring highly degraded sites. Here we propose a comprehensive landscape genomic approach to assist the restoration of moderately disturbed and highly degraded sites. To illustrate it we employ genomic datasets comprising thousands of single nucleotide polymorphisms from two plant species suitable for the restoration of iron-rich Amazonian Savannas. We first use a subset of neutral loci to assess genetic structure and determine the genetic neighborhood size. We then identify genotype-phenotype-environment associations, map adaptive genetic variation, and predict adaptive genotypes for restoration sites. Whereas local provenances were found optimal to restore a moderately disturbed site, a mixture of genotypes seemed the most promising strategy to recover a highly degraded mining site. We discuss how our results can help define site-adjusted provenancing strategies, and argue that our methods can be more broadly applied to assist other restoration initiatives.