Волонтерство как социальный институт

Работа выполнена при поддержке РГНФ в рамках проекта №14-03-00072

Reconciling biodiversity conservation and flood risk reduction : The new strategy for freshwater protected areas

Aim: Natural disaster risk reduction (DRR) is becoming a more important function of protected area (PAs) for current and future global warming. However, biodiversity conservation and DRR have been handled separately and their interrelationship has not been explicitly addressed. This is mainly because, due of prevailing strategies and criteria for PA placement, a large proportion of PAs are currently located far from human-occupied areas, and habitats in human-occupied areas have been largely ignored as potential sites for conservation despite their high biodiversity. If intensely developed lowland areas with high flooding risk overlap with important sites for biodiversity conservation, it would be reasonable to try to harmonize biodiversity conservation and human development in human-inhabited lowland areas. Here, we examined whether extant PAs can conserve macroinvertebrate and freshwater fish biodiversity and whether human-inhabited lowland flood risk management sites might be suitable to designate as freshwater protected areas (FPAs). Location: Across Japan. Methods: We examined whether extant PAs can conserve macroinvertebrate and freshwater fish biodiversity and analysed the relationship between candidate sites for new FPAs and flood disaster risk and land use intensity at a national scale across Japan based on distribution data for 131 freshwater fish species and 1395 macroinvertebrate species. Results: We found that extant PAs overlapped with approximately 30% of conservation-priority grid cells (1 km2) for both taxa. Particularly for red-listed species, only one species of freshwater fish and three species of macroinvertebrate achieved the representation target within extant PAs. Moreover, more than 40% of candidate conservation-priority grid cells were located in flood risk and human-occupied areas for both taxa. Main conclusions: Floodplain conservation provides suitable habitat for many freshwater organisms and helps control floodwaters, so establishing new FPAs in areas with high flood risk could be a win-win strategy for conserving freshwater biodiversity and enhancing ecosystem-based DRR (eco-DRR)

Stream grazers determine their crawling direction on the basis of chemical and particulate microalgal cues

This study aimed to determine the association between herbivore behavior and cues from producers. We used stream grazer Glossosoma larvae and determined their crawling direction in relation to chemical and visual cues from microalgae. The experimental treatments included control (no cue), particulate (chemical and particulate cues), and dissolved (chemical cue) cues from microalgae. The experimental water samples were randomly placed into either arm of a Y-shaped channel, and the crawling direction of the grazers was determined. Although the grazers crawled toward the arm containing either particulate or dissolved cues, they preferred the arm with particulate cues. This suggested that grazers responded well to both particulate (i.e., drifting algal cells) and chemical (algal smell) cues, and that particulate cues were more important for foraging. In natural habitats, grazers detect cues from producers and change their behaviors to maintain a balance between top-down and bottom-up cues

Effects of stream grazers with different functional traits on the spatial heterogeneity of periphyton mats

Background Grazing activity on periphytic mats determines mat structure and spatial heterogeneity. Spatial complexity in stream periphyton is highly divergent and may depend on the functional traits of the different primary consumers species (i.e., grazers) such as mouthpart morphology, feeding behavior, and feeding activity. We evaluated the effect of grazing by three species having different functional traits on periphytic mat structure with a focus on mohthpart morphology. Methods An enclosure experiment was conducted in a stream located in the Nara Prefecture of Japan using two caddisflies with scraping mouthparts, Micrasema quadriloba and Glossosoma, and one mayfly, Epeorus, with brushing mouthparts. The spatial heterogeneity of chlorophyll a(Chl a) was evaluated, and the periphytic mat was analyzed using scanning electron microscopy (SEM) after a 12-d feeding experiment. Results Our results showed the differences in the spatial heterogeneity of the periphytic mats, such as differences in Chl a levels, grazed by the different grazing species. The strongest effect on the spatial heterogeneity and periphytic abundance was observed for Micrasema quadriloba, a caddisfly species with scraping mouthparts. Epeorus mayfly, with brushing mouthparts and high-mobility behavior, produced the weakest effect on spatial heterogeneity. Glossosoma caddisflies had moderate effects on periphytic spatial heterogeneity and abundance. Our results suggest that differences in grazing effects are largely dependent on grazer mouthparts and behavior

The use of algal-mat habitats by aquatic insect grazers: effects of microalgal cues. Basic and Applied Ecology 7:153–158 DOI 10.1016/j.baae.2005.04.009

Summary Microalgal biomass is important for the growth and survival of aquatic insect grazers, and we hypothesized that the abundance of microalgae mediates the habitat-use behavior of aquatic insect grazers in stream ecosystems. To test this question under laboratory conditions, we prepared four types of experimental habitat in an artificial stream: untreated ceramic plates, ceramic plates with thin algal mats, ceramic plates with thick algal mats, and natural stone with algal mats. We compared the upstream movement forward each experimental habitat substrate by caddisfly grazer Glossosoma larvae. At day and at night, a significantly greater number of Glossosoma larvae were attracted by thin and thick algal mats as well as by natural stones than by the untreated ceramic plate. At night, thick algal mats attached significantly more larvae than thin algal mats. Thus, Glossosoma larvae can recognize and respond to the abundance of microalgae through microalgal cues (chemical and/or algal drift), which induce the movement of Glossosoma larvae to habitats with high microalgal biomass. We propose that cues from microalgae are recognized by grazers in stream ecosystems

A cross-system meta-analysis reveals coupled predation effects on prey biomass and diversity

Predator diversity and abundance are under strong human pressure in all types of ecosystems. Whereas predator potentially control standing biomass and species interactions in food webs, their effects on prey biomass and especially prey biodiversity have not yet been systematically quantified. Here, we test the effects of predation in a cross-system meta-analysis of prey diversity and biomass responses to local manipulation of predator presence. We found 291 predator removal experiments from 87 studies assessing both diversity and biomass responses. Across ecosystem types, predator presence significantly decreased both biomass and diversity of prey across ecosystems. Predation effects were highly similar between ecosystem types, whereas previous studies had shown that herbivory or decomposition effects differed fundamentally between terrestrial and aquatic systems based on different stoichiometry of plant material. Such stoichiometric differences between systems are unlikely for carnivorous predators, where effect sizes on species richness strongly correlated to effect sizes on biomass. However, the negative predation effect on prey biomass was ameliorated significantly with increasing prey richness and increasing species richness of the manipulated predator assemblage. Moreover, with increasing richness of the predator assemblage present, the overall negative effects of predation on prey richness switched to positive effects. Our meta-analysis revealed strong general relationships between predator diversity, prey diversity and the interaction strength between trophic levels in terms of biomass. This study indicates that anthropogenic changes in predator abundance and diversity will potentially have strong effects on trophic interactions across ecosystems

Data from: Distribution and drift dispersal dynamics of a caddisfly grazer in response to resource abundance and its ontogeny

Stream grazers have a major impact on food web structure and the productivity of stream ecosystems; however, studies on the longitudinal (upstream versus downstream) and temporal changes in their drift dynamics and resulting distributions remain limited. Here, we investigated the longitudinal and temporal distributions and drift propensity of a trichopteran grazer, the caddisfly, Micrasema quadriloba, during its life cycle in a Japanese stream. The distribution of larvae significantly shifted downstream during the fifth instar larval stage during late winter; with periphyton abundance (i.e. their food source) showing similar shifts downstream. Therefore, our results show that the drift dispersal the caddisfly occurs in response to decline in available food resources (i.e. food-resource scarcity) and an increase in food requirements by growing individuals. Furthermore, our results show that this observed longitudinal shift in larval distribution varies through their life cycle, because the drift dispersal of fifth instar larvae was greater than that of immature larvae. The correlation between periphyton abundance and drift propensity of fourth instar larvae was not statistically significant, whereas that of fifth instar larvae was significantly negative. In conclusion, we detected an ontogenetic shift in drift propensity, which might explain the longitudinal and temporal distributions of this species

Spatial structure of fungal DNA assemblages revealed with eDNA metabarcoding in a forest river network in western Japan

Growing evidence has revealed high diversity and spatial heterogeneity of fungal communities in local habitats of terrestrial ecosystems. Recently, the analysis of environmental DNA has been undertaken to study the biodiversity of organisms, such as animals and plants, in both aquatic and terrestrial habitats. In the present study, we investigated fungal DNA assemblages and their spatial structure using environmental DNA metabarcoding targeting the internal transcribed spacer 1 (ITS1) region of the rRNA gene cluster in habitats across different branches of rivers in forest landscapes. A total of 1,956 operational taxonomic units (OTUs) were detected. Of these, 770 were assigned as Ascomycota, 177 as Basidiomycota, and 38 as Chytridiomycota. The river water was found to contain functionally diverse OTUs of both aquatic and terrestrial fungi, such as plant decomposers and mycorrhizal fungi. These fungal DNA assemblages were more similar within, rather than between, river branches. In addition, the assemblages were more similar between spatially closer branches. This spatial structuring was significantly associated with geographic distances but not with vegetation of the catchment area and the elevation at the sampling points. Our results imply that information on the terrestrial and aquatic fungal compositions of watersheds, and therefore their spatial structure, can be obtained by investigating the fungal DNA assemblages in river water