Ecologies, Volume 4, Issue 1 (March 2023) – 14 articles

Agricultural expansion has had a detrimental effect on tropical forests and the animal communities that depend on them. Agroforestry systems, however, with their more complex tree and plant communities, have been shown to be important habitats for a range of globally threatened species, including nocturnal animals. Here, we present novel data on the encounter rates of seven species of nocturnal mammals in relation to agroforestry systems within four national parks and associated plantations in Bangladesh to examine if encounter rates were influenced by the human population density, presence of plantations, and human access as represented by a Human Influence Index of anthropogenic disturbance. We walked 70.3 km of transects with only semi-natural forest, 26.9 km of transects with semi-natural forest and gardens, and 21.7 km of transects with semi-natural forest and monocultures over 55 nights from 2017–2019. Of the seven species of nocturnal mammals we detected, all were present in Satachari National Park, whereas six occurred in Lawachara National Park, Rajkandi Forest Range, and Rema-Kalenga Wildlife Sanctuary. Within these national parks, three species (Bengal slow loris, large Indian civet, particolored flying squirrel) were more frequently recorded in areas with human disturbance, especially agroforestry plantations. With declining forest cover in Bangladesh, we highlight here the potential of agroforestry systems as emerging important habitats for these species. We encourage long-term studies of these lesser-studied taxa to understand fully the capacity of agroforestry systems in order to support their long-term conservation. Full article

Hummingbirds are charismatic fauna that provide important pollination services, including in the continental US, where 15 species regularly breed. Compared to other birds in North America, hummingbirds (family Trochilidae) have a unique exposure route to pesticides because they forage on nectar. Therefore, hummingbirds may be exposed to systemic pesticides borne in nectar. They also may be particularly vulnerable to pesticide exposure due to their small size and extreme metabolic demands. We review relevant factors including hummingbird life history, nectar residue uptake, and avian bioenergetic considerations with the goal of clearly identifying and articulating the specific modeling challenges that must be overcome to develop and/or adapt existing modeling approaches. To help evaluate these factors, we developed a dataset for ruby-throated hummingbirds (Archilochus colubris) and other avian species potentially exposed to pesticides. We used the systemic neonicotinoid pesticide imidacloprid as an illustration and compared results to five other common current use pesticides. We use the structure of Pop-GUIDE to provide a conceptual modeling framework for implementation of MCnest and to compile parameter values and relevant algorithms to predict the effects of pesticide exposure on avian pollinators. Conservative screening assessments suggest the potential for adverse effects from imidacloprid, as do more refined assessments, though many important limitations and uncertainties remain. Our review found many areas in which current USEPA avian models must be improved in order to conduct a full higher-tier risk assessment for avian pollinators exposed to neonicotinoid insecticides, including addition of models suitable for soil and seed treatments within the MCnest environment, ability to include empirical residue data in both nectar and invertebrates rather than relying on existing nomograms, expansion of MCnest to a full annual cycle, and increased representation of spatial heterogeneity. Although this work focuses on hummingbirds, the methods and recommendations may apply more widely to other vertebrate pollinators. Full article

Lichens are symbiotic partnerships between a filamentous fungus and a photosymbiotic “alga”. Studies show that lichens harbor endothallic fungi, but that some taxa have been difficult to isolate from the main filamentous thallus-forming fungus and other faster growing lichenicolous/endothallic fungi. Therefore, we aimed to develop and evaluate liquid yeast-enrichment strategies to (1) isolate lichen-associated yeasts in pure culture, and (2) determine the taxonomic placement and breadth of the diversity of culturable yeasts. Eighty-two lichen samples were collected and washed with distilled water, and healthy thalli were ground up and added to seven different yeast-enrichment broths. Yeast colonies were isolated in pure culture and identified using molecular techniques. Initial isolates were identified using BLASTn analysis, and a taxonomic refinement was completed using PhyML analysis. In total, 215 isolates were obtained. The most prevalently isolated ascomycetous yeasts were within the Dothideomycetes (Aureobasidium, Plowrightia, and Dothiora), while the most frequently isolated basidiomycetous yeasts belonged to the genera Curvibasidium, Sporobolomyces, and Tremella. The generic placements could not be determined for 17 isolates, and in total 25 novel species were recovered. The results of this research indicate that (1) lichen-associated yeasts are diverse, (2) employing liquid enrichment strategies is effective for isolating many of these, and (3) lichen thalli represent a valuable untapped reservoir of diverse and novel yeast species. Full article

Nanoparticles are man-made materials defined as materials smaller than 100 nm in at least one dimension. Titanium oxide nanoparticles are of great interest because of their extensive use in self-care products. There is a lack of nanotoxicological studies of TiO₂ NPs in benthic organisms to have evidence about the effects of these pollutants in freshwater ecosystems. Atya lanipes is a scraper/filter that can provide a good nanotoxicological model. This study aims to determine how the TiO₂ NPs can develop a toxic effect in the larvae of the Atya lanipes shrimp and to document lethal and sublethal effects after acute exposures to TiO₂ NP suspensions of: 0.0, 1.0, 10.0, 50.0, 100.0, and 150.0 mg/L. The results show that early exposure to TiO₂ NPs in Atya lanipes creates an increase in mortality at 48 and 72 h exposures, hypoactivity in movements, and morphological changes, such as less pigmentation and the presence of edema in exposed larvae. In conclusion, TiO₂ NPs are toxic contaminants in the larval stage of the Atya lanipes. It is necessary to regulate these nanoparticles for purposes of the conservation of aquatic biodiversity, especially for freshwater shrimp larvae and likely many other larvae of filter-feeding species. Full article

Impact of pollination on the agri-food sector is of paramount importance. Pollinators contribute to the maintenance of ecosystems, the reproduction and survival of many plants, and their presence usually leads to increased yield and quality of agricultural products. Breeding and selecting for plant traits for enhancing pollinator visits could therefore lead to more resilient farming systems. In stating the advantages of enhancing pollinators in agricultural systems, this study was designed aiming to assess six cowpea accessions for their flower traits and their effect on insect-pollinators. Pollinators species abundance and foraging activity was recorded and their impact on yield was investigated. Twenty-five of the twenty-seven flower traits studied differed statistically significantly among cowpea accessions. The main pollinators recorded belonged to the genus Xylocopa (Latreille, 1802). Seed and fresh pod yield was not affected by pollinators. The floral traits related to pollinators abundance and foraging activity were flower color, inflorescence position and the hours that the flowers per plant remained open during the day. However, they were not related linearly to pollinators abundance and foraging activity; therefore, they did not constitute safe traits for selection aiming to increase pollinators visitation. The findings suggested that other traits, such as pollen and nectar reward, probably perform a more important role in attracting pollinators compared to flower traits. Full article

Hot springs are known as highly adverse extreme environments where thermophilic and hyperthermophilic microorganisms can survive. We describe taxonomic diversity of several microbial biofilms collected along water temperature gradient in hot streams in the aquatic system of the Stolbovskie hot springs on Kunashir Island, Kurils, Russia. The taxonomic composition of the studied microbial communities was assessed by the 16S rRNA gene metabarcoding for bacteria and archaea, and by the 18S rRNA gene metabarcoding for protists. Richness and diversity of bacteria in the geothermal microbial communities decreased with the increase of temperature, while for archaea, the tendency was the opposite. Ciliophora was the most represented taxon of protists. The biofilms of various kinds that we found in a very local area of the geothermal system were different from each other by taxonomic composition, and the level of their taxonomic diversity was significantly influenced by water temperature. Full article

The objective of the manuscript was to study the effects of dead wood on macroinvertebrates (MI) assemblages occupying different habitat patches. Three streams were studied, with control and wooded sections in each stream from which MI were sampled for all substrate types (wood, fine detritus, gravel, sand). This contribution deals with three German streams Ihle, Nieplitz, and Verlorenwasser, which belong to the stream type 14 (sand-dominated lowland stream) and are located in the landscape unit Fläming. This type of stream, where large wood could be most influential, has been relatively understudied. This study focused on quantifying substrate distribution and macroinvertebrate taxonomy and performing statistical analysis of MI densities with regard to substrate type. The area-specific invertebrate assemblages were differentiated for MI density, dry matter density and taxonomic richness of invertebrates. In addition to macroinvertebrates, a special focus was on aquatic and semi-aquatic insects. There were significant differences between the control and wooden sections. The macroinvertebrate assemblages (individual density, dry matter density and species richness) of the detritus of the wood sections only in the Verlorenwasser was significantly and positively affected (two or three times) by the deadwood. Detritus in the wood sections of the Nieplitz and Verlorenwasser contained more sensitive species like EPT than detritus from the control sections. On the other hand, no significant difference in MI populations were determined for the sand of the wood sections compared to the sand of the control sections. In all water bodies, the wood substrate promoted all investigated indicators of macrozoobenthos as compared to sand of the wood sections. Detritus significantly promoted macrozoobenthos colonization in the wood sections as compared to sand of the Nieplitz and the Verlorenwasser. The MI density and dry matter density in the Ihle was also significantly promoted by detritus, although not significantly with regard species richness. Two significant correlations were also identified. The more sand that was present in the Ihle and the Verlorenwasser, the more the macroinvertebrate assemblages were inhibited. Additionally, the larger the area of detritus in the Ihle and the area of wood in the Nieplitz, the more MI populations were encouraged. The influence of the deadwood position on MI was also investigated, but there was no significant difference. Incline bridges, flow guides and parallel wood position types were settled in similar quality and quantity. Full article

Rhizosphere soil ecosystems are represented by the diversity of different soil aggregate-size classes, such as large macroaggregates, small macroaggregates, mesoaggregates, and microaggregates. Though these aggregate-size classes represent distinct biological, chemical, and physical properties, little is known about their dynamics and relationships with belowground and aboveground plant traits. In this study, we examined the relationships of various soil aggregate-size classes and their organic carbon contents with many aboveground and belowground soybean plant traits. Our study revealed several novel and interesting relationships between soil structural properties and plant traits. Notably, small macroaggregates represented a major portion of the rhizosphere soil ecosystem of soybean plants while organic carbon contents decreased with decreasing size of soil aggregates. Only microaggregates showed a significant relationship with root architectural traits, such as length and surface area. Among all soil aggregate size classes, the abundance of small macroaggregates and the organic carbon contents of microaggregates were better correlated with plant traits. In general, organic carbon contents of different soil aggregate-size classes showed positive correlations with leaf trichome density (defense traits) and major macronutrients, such as root P, K, and S contents; while there were mostly negative correlations with some micronutrient (Ca, Mn, Zn, Cu, B, and Mg) contents of roots and shoots. However, the abundance of small macroaggregates mostly positively correlated with the mineral contents of plant roots and shoots. Collectively, the positive and negative correlations of organic carbon contents of different soil aggregate-size classes with trichomes (defense) and physiological traits (micro-mineral contents) suggest their significance in plant nutrition and defense. Though our results suggest the relationships of soil aggregate properties with aboveground and belowground traits, further research is needed to discern the role of soil structural traits in mediating plant growth, development, defense, and physiology. Full article

Assessing a taxon’s response to change in environmental variables is fundamental knowledge to understanding trends in species diversity, abundance, and distribution patterns. This is particularly needed on Borneo, where knowledge on Odonata populations in different habitats is poor. To address this gap, we present the first study investigating the relationship between morphology and species distribution of Odonata communities in a heath (kerangas)-dominated mixed-mosaic-lowland forest in southern Borneo. We sampled 250-m line transects in three habitat types: mixed peatcswamp, kerangas, and low-pole peatcswamp, with weekly surveys from December 2019 to February 2020. A total of 309 individuals were detected from 25 species. Anisoptera and Zygoptera diversity was the highest in mixed peatcswamp and lowest in low pole, while abundance was the highest in low pole and lowest in kerangas; with kerangas notably harboring a very small sample size. Odonata community assemblages differed most between mixed peat swamp and low pole. Morphological data were compared between suborders and habitats. Anisoptera showed significantly larger thoraces, hindwings, and hindwing-to-body ratio than Zygoptera. Anisoptera in low pole were significantly smaller in body, thorax, and hindwing compared to both kerangas and mixed peat swamp. Anisoptera showed a strong association with pools and Zygoptera with flowing water. Heterogeneity, habitat characteristics, presence of specialists, body size, and the interaction between species’ morphological traits and habitat characteristics likely explained the trends observed. Full article

Species with similar resource requirements cannot coexist for long. To facilitate co-existence, carnivores adapt different strategies to partition the available resources in space and time. In high-altitude ecosystems with limited resources the operation becomes complex. We assessed species diversity and spatio-temporal resource partitioning among felid species inhabiting the intricate habitats of Khangchendzonga Biosphere Reserve (KBR), Eastern Himalaya. We used systematic camera trap surveys along with abundance and overlap indices to generate information on their space use and activity patterns. We recorded six species of felids belonging to five genera, including four species of global conservation importance. The differential use of space by felids was observed with respect to the habitat types determined by sharp altitudinal gradients with varied levels of spatial and altitudinal overlap. Maximum overlap was observed among Asiatic golden cat Catopuma temminckii, jungle cat Felis chaus and clouded leopard Neofelis nebulosa. The felids had distinct activity profiles from one other, particularly between golden cat and leopard cat Prionailurus bengalensis. Pianka’s index also provided weak evidence for temporal overlap among species. The overall results indicate that habitat heterogeneity facilitates primary separation at the spatial scale, although species are also segregated temporally. Golden cat was the most adaptive felid in the area, depicting a peculiar pattern of spatio-temporal segregation with other species. We suspect either intense competition or dietary segregation among some species, and propose a further investigation of their diet and the activity patterns of their prey. The study presents an early template of carnivore community organization in resource-scarce high-altitude environments, thus, offering huge ecological and conservation significance. Full article

In recent decades, sustainable forest management has been increasingly recognized, promoting the diffusion of silvicultural practices aimed at considering all components of the forest system. Deadwood is an important component of the forest ecosystem. It plays a fundamental role in providing nutrients and habitats for a wide variety of saprotrophic and heterotrophic organisms and significantly contributes to soil formation and carbon storage. Deadwood is inhabited by a plethora of organisms from various kingdoms that have evolved the ability to utilize decaying organic matter. This community, consisting of both eukaryotic and prokaryotic species, can be defined as “necrobiome”. Through the interactions between its various members, the necrobiome influences the decay rates of deadwood and plays a crucial role in the balance between organic matter decomposition, carbon sequestration, and gas exchanges (e.g., CO₂) with the atmosphere. The present work aims to provide an overview of the biodiversity and role of the microbial communities that inhabit deadwood and their possible involvement in greenhouse gas (CO₂, N₂O, and CH₄) emissions. Full article

The ecological half-life of ¹³⁷Cs was calculated individually for four symbiotrophic fungi species (Boletus edulis, Imleria badia, Suillus luteus, Paxillus involutus) at 10 sampling sites in the Chornobyl exclusion zone and in the Kyiv region. It was found that the maximum rate of excretion of 137Cs from the fungi organisms is characteristic for the territory with the maximum levels of soil contamination, i.e., for a zone near Chornobyl Nuclear Power Plant. In areas with low ¹³⁷Cs content, a slowing down of the excretion rate predominates. These results reveal different fungal response to the distinct concentration levels of ¹³⁷Cs in forest ecosystems. This observation further suggests that radiocaesium can be selectively accumulated by fungi and used in their life processes. Presence of this ¹³⁷Cs retention mechanism in fungi leads to a longer contamination of woody plants-symbionts. Full article

Pyrus calleryana was intentionally introduced to North America from east Asia in the early 1900s as rootstock for the edible pear tree, Pyrus communis. It was identified as an ideal decorative, agricultural, and horticultural tree because of its small stature, early spring flowering, fire blight resistance and inoffensive fruits. P. calleryana escaped cultivation and is now considered an invasive species, typically found on roadsides, prairies, and fields. The aim of this study is to characterize pollinator community diversity from planted and feral trees, as well as diversity as it compares to expected communities derived from research-grade iNaturalist observations. Pollinators were collected by hand on planted and feral P. calleryana trees in April 2018–2022. A total of 14 taxa of insect pollinator were collected from P. calleryana flowers, with similar levels of diversity of pollinator taxa collected from planted and feral trees, and Apis mellifera and Andrena spp. the most common taxa observed. The sampled pollinator community did not differ from the expected pollinator communities generated using the iNaturalist data on either the planted or feral P. calleryana. Full article