Search

SecSel, a protected-area prioritization tool, has been developed to help design areas that efficiently protect multiple features, including conservation of biodiversity and use of ecosystem services. The prioritization by SecSel is based on evaluation of the local units of each feature. The evaluation metrics should be quantitative but need not be ratio scale. The minimum requirement of the input data is that they are ordinal. The conservation target is the number of local units with high values of each feature to be protected in the area. SecSel can handle conflicts among features, including conflicts between conservation and utilization of land or specific ecosystem functions. Before the selection procedure, one of a conflicting pair of features in a site is discarded. That decision is based on the dispensability of the local unit to fulfilling the conservation target of each feature. SecSel also considers the cost of including each site in the protected area and the compactness of the area in terms of total boundary length or the distance to the nearest site. To demonstrate the functionality of Secsel, we used it to design land use in an alpine region of northern Japan where conservation of alpine vegetation and its recreational use are important considerations.

Farmlands are becoming more important as waterfowl foraging habitats, while natural wetlands are being lost globally. However, it is unclear how waterfowl coexist in agricultural landscapes by resource partitioning. We evaluated the diets of seven sympatric dabbling ducks foraging in rice paddy and lotus fields around Lake Kasumigaura, the second largest lake in Japan, during two wintering seasons (from November to February) by faecal DNA metabarcoding using chloroplast trnL and mitochondrial CO1 region sequences. We examined 420 faecal samples and found different patterns of dietary diversity and composition among the duck species. The pattern also differed between plant and invertebrate food. Dietary niche partitioning was clear in plant food. Large‐bodied ducks intensively use crop plants, and other ducks might mediate competition by using terrestrial and aquatic plants that are suitable for their foraging behaviours or microhabitats. Dietary segregation among species was the most apparent in February, when the abundance of foraging ducks was the largest. This study illustrated the complex pattern of dietary niche partitioning of dabbling ducks in agricultural landscapes, which might be difficult to evaluate by conventional approaches. The availability of crop plants, as well as other plant food resources in flooted areas and farmland dikes, may enable ducks to coexist by spatial or behavioural resource partitioning. [ABSTRACT FROM AUTHOR]

To evaluate the effects of flowering phenology on pollen flow distance and spatial genetic structure in a population of a bumblebee-pollinated herb, Primula sieboldii, we investigated the flowering phenology of 1712 flowers of 97 genets in a population in Nagano Prefecture, Japan, and constructed a mating model based on the observed mating pattern, which was revealed by paternity analysis using 11 microsatellite markers. The effects of flowering phenology were inferred by comparing estimated pollen flow distance and the level of heterozygosity in the next generation between two scenarios. In the first scenario, both the intergenet distance and flowering phenology influenced mating opportunity, while in the second scenario only intergenet distance influenced mating opportunity. Although the frequency distribution of pollen flow distance at the population level did not differ significantly between the two scenarios, the mean pollen flow distance of several flowers increased by more than 10 m as a result of variation in flowering phenology. Furthermore, accounting for flowering phenology predicted change in heterozygosity in the next generation from -0.04 to 0.07. The results showed that flowering phenology can affect pollen flow distance and spatial genetic structure. Key words: bumblebee: flowering time: heterostyly; mating model: microsatellite; Nagano Prefecture: paternity analysis: Primulaceae.

Abstract Background The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum) and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium). Results A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT) after the colonization of the gut by the rumen Ciliates. Conclusion Among the HGT candidates, we found an over-representation (>75%) of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches.

Background and Aims The tidal flats on which mangrove plants grow tend to have low soil nitrogen contents because nitrogen-containing litter is repeatedly washed offshore by ebb tides. Under such circumstances, it is unclear how mangrove plants acquire the nitrogen required to support their vigorous growth. In the present work, chemical and biological characteristics of diazotrophy around mangrove plant roots were surveyed under natural conditions to elucidate mangrove–diazotroph relationships. Methods Soil nitrogenase activity of a representative mangrove plant, Rhizophora stylosa , which has a broad geographical distribution, was measured using the acetylene reduction assay at forest, tree and prop root scales. In addition, diazotrophic community composition was compared between rhizosphere and bulk soil based on sequencing of nifH genes. Key Results Soil nitrogenase activity was high near prop roots, and this pattern was enhanced as soil live root content increased. At the forest scale, we observed high soil nitrogenase activity (acetylene-reducing activity) inside the forest (the highest value was 90.9 µmol C2H2 min−1 cm−3, average 46.8 ± 18.2 µmol C2H2 min−1 cm−3). Rates decreased sharply from the forest to the tidal flat (range 1.2–22.2 µmol C2H2 min−1 cm−3, average 7.9 ± 4.5 µmol C2H2 min−1 cm−3). The nifH operational taxonomic unit composition differed significantly among forest and tree rhizospheres and the bulk soil (P < 0.0001). Conclusions Our results suggest that the accumulation of diazotrophs around R. stylosa mangrove trees enhances the supply of biologically fixed nitrogen to the mangrove roots. This supply is especially important when the soil naturally contains little nitrogen. This nitrogen acquisition system may be a key process that explains the high productivity of mangrove ecosystems. [ABSTRACT FROM AUTHOR]

Conservation planning has generally used models with a static spatial distribution of species to predict the likely occurrence of species. However, static data do not usually capture rapid changes in the abundance of endangered species or cryptic life stages such as the dormancy stage of eggs and seeds. Little is known about how neglecting dynamic population processes, such as recovery processes, can affect the outcomes of spatial prioritization in conservation planning.In this study, we investigated the distribution of 62 aquatic plant species, including 23 threatened species, in 415 agricultural ponds for 37 years to examine the importance of including recovery processes in conservation planning. Using long‐term historical presence–absence data and seedbank longevity data for aquatic macrophytes, we estimated rates of population disappearance and recovery for each species in each pond over the next 100 years.Average rates of recovery exceeded 0, 0.2, and 0.4 in 85.4%, 40.3%, and 4.8% of aquatic plant species, respectively. Simulation results suggested that the extinction risk for a species greatly decreased when recovery processes were considered. We found that including recovery processes in target species populations increased the performance of spatial prioritization by protecting more species in a smaller number of protected ponds. Spatial ranking of ponds for species conservation differed substantially among scenarios that included and excluded population recovery processes, suggesting that conservation priorities based on complementarity analysis are sensitive to underlying assumptions.Synthesis and applications. Our dynamic approach, which considers recovery processes of species, contributes to more effective conservation planning by reducing bias in the prediction of species' state, given that cryptic life stages are ubiquitous among many plants and some animals. Time‐series presence/absence data on target species are quite useful for the approach and are often archived by participatory monitoring. Thus, the opportunities for applying our method are broad, especially for conservation prioritization and decision‐making at the local scale. Our dynamic approach, which considers recovery processes of species, contributes to more effective conservation planning by reducing bias in the prediction of species' state, given that cryptic life stages are ubiquitous among many plants and some animals. Time‐series presence/absence data on target species are quite useful for the approach and are often archived by participatory monitoring. Thus, the opportunities for applying our method are broad, especially for conservation prioritization and decision‐making at the local scale. [ABSTRACT FROM AUTHOR]