Incongruent Spatial Distribution of Taxonomic, Phylogenetic, and Functional Diversity in Neotropical Cocosoid Palms

Biodiversity can be quantified by taxonomic, phylogenetic, and functional diversity. Current evidence points to a lack of congruence between the spatial distribution of these facets due to evolutionary and ecological constraints. A lack of congruence is especially evident between phylogenetic and taxonomic diversity since the name and number of species are an artificial, yet commonly used, way to measure biodiversity. Here we hypothesize that due to evolutionary constraints that link phylogenetic and functional diversity, areas with higher phylogenetic and functional diversity will be spatially congruent in Neotropical cocosoid palms, but neither will be congruent with areas of high taxonomic diversity. Also, we hypothesize that any congruent pattern differs between rainforests and seasonally dry forests, since these palms recently colonized and diversified in seasonally dry ecosystems. We use ecological niche modeling, a phylogenetic tree and a trait database to test the spatial congruence of the three facets of biodiversity. Taxonomic and phylogenetic diversity were negatively correlated. Phylogenetic and functional diversity were positively correlated, even though their spatial congruence was lower than expected at random. Taken together, our results suggest that studies focusing solely on large-scale patterns of taxonomic diversity are missing a wealth of information on diversification potential and ecosystem functioning.

Fluid Nest Membership Drives Variable Relatedness in Groups of a Facultatively Social Bee

Kin selection theory has dominated our understanding of the evolution of group living. However, many animal groups form among non-relatives, which gain no indirect fitness benefits from cooperating with nestmates. In this study, we characterized the relatedness and inter-nest migration behavior of the facultatively social carpenter bee, Xylocopa sonorina. Nesting constraints due to costly nest construction in this species give rise to intense intraspecific competition over access to existing nests. We used mark-recapture techniques to characterize patterns of dispersal and nest relocation within a nesting aggregation of spatially clustered nests. Two-thirds of bees relocated at least once during the reproductive season, likely to seek reproductive opportunities in another nest. This fluid nest membership creates opportunities for association among non-relatives. To assess the effects of this dynamic nesting behavior on group relatedness, we used microsatellite analysis to estimate relative relatedness within and between nests in the aggregation. We found that relatedness was variable across sampling years, but that in many cases nestmates were no more related to one another than they were to non-nestmate bees in the population. Together, these results suggest that group composition in X. sonorina may result from strategies to maximize direct fitness. This study supports the hypothesis that factors beyond kinship, such as ecological constraints, are likely to drive group formation in this species.

Microwave Assisted Biodiesel Production Using Heterogeneous Catalysts

As a promising renewable fuel, biodiesel has gained worldwide attention to replace fossil-derived mineral diesel due to the threats concerning the depletion of fossil reserves and ecological constraints. Biodiesel production via transesterification involves using homogeneous, heterogeneous and enzymatic catalysts to speed up the reaction. The usage of heterogeneous catalysts over homogeneous catalysts are considered more advantageous and cost-effective. Therefore, several heterogeneous catalysts have been developed from variable sources to make the overall production process economical. After achieving optimum performance of these catalysts and chemical processes, the research has been directed in other perspectives, such as the application of non-conventional methods such as microwave, ultrasonic, plasma heating etc, aiming to enhance the efficiency of the overall process. This mini review is targeted to focus on the research carried out up to this date on microwave-supported heterogeneously catalysed biodiesel production. It discusses the phenomenon of microwave heating, synthesis techniques for heterogeneous catalysts, microwave mediated transesterification reaction using solid catalysts, special thermal effects of microwaves and parametric optimisation under microwave heating. The review shows that using microwave technology on the heterogeneously catalysed transesterification process greatly decreases reaction times (5–60 min) while maintaining or improving catalytic activity (>90%) when compared to traditional heating.

Hydropower reservoir reduces Great Argus Argusianus argus density in proximity to its shore

Summary Habitat degradation due to hydropower development within protected areas has a marked negative effect on resident wildlife species. However, efforts to develop appropriate conservation and management plans are hampered by a general lack of quantitative information and a poor understanding of relevant ecological constraints. Great Argus Argusianus argus, a large galliform species sensitive to habitat degradation, can reflect the impacts of the Chiew Larn reservoir in southern Thailand on local wildlife. Great Argus abundance in the remaining lowland areas of Khlong Saeng Wildlife Sanctuary (KSWS) was estimated using line transects along the Chiew Larn reservoir edges and in the forest interior between February and April 2017. The population estimate for KSWS was 108 individuals (95% CI: 41–272) based on the sampled area of 18.06 km2, with a density estimate of 5.9 calling males/km2. The abundance increased with increased distance from the reservoir shoreline, which might be related to the high level of direct and indirect human disturbance close to the hydropower reservoir.

Temporally robust spatial structure in ecosystems explained by local biodiversity regulation

The distribution in species' site occupancy is a fundamental pattern in spatial ecology. Despite decades of research, the mechanisms responsible for the shape of the distribution remain incompletely understood. Here, we simultaneously examining both spatial and temporal patterns of site occupancy in communities of macroinverterbrates, macrophytes and diatoms. We show that a simple patch dynamics model explains both the spatial structure and temporal dynamics in English rivers. The key mechanism responsible for the emergent spatial structure in the model are intrinsic regulation of biodiversity at the local scale which, when combined with inter-site dispersal and regional-scale invasion, drives local colonisation and extinction. Our analysis supports the notion that metacommunities exist in a kind of dynamic steady state arising from local ecological constraints and that this intrinsic regulation can drives the emergence of a wide variety of macroecological patterns.

Predator–Prey System: Bachelor Herding of the Prey Imposes Ecological Constraints on Predation

Bachelor herd behavior is very common among juvenile animals who have not become sexually matured but have left their parent groups. The complex grouping or schooling behavior provides vulnerable juveniles refuge from predation and opportunities for foraging, especially when their parents are not within the area to protect them. In spite of this, juvenile/immature prey may easily become victims because of their greenness while on the other hand, adult prey may be invulnerable to attack due to their tricky manoeuvring abilities to escape from the predators. In this study, we propose a stage-structured predator–prey model, in which predators attack only the bachelor herds of juvenile prey while adult prey save themselves due to small predator–prey size ratio and their fleeing capability, enabling them to avoid confrontation with the predators. Local and global stability analysis on the equilibrium points of the model are performed. Sufficient conditions for uniform permanence and the impermanence are derived. The model exhibits both transcritical as well as Hopf bifurcations and the corresponding numerical simulations are carried out to support the analytical results. Bachelor herding of juvenile prey as well as inaccessibility of adult prey restricts the uncontrolled predation so that prey abundance and predation remain balanced. This investigation on bachelor group defence brings out some unpredictable results, especially close to the zero steady state. Altogether, bachelor herding of the juvenile prey, which causes unconventional behavior near the origin, plays a significant role in establishing uniform permanence conditions, also increases richness of the dynamics in numerical simulations using the bifurcation theory and thereby, shapes ecosystem properties tremendously and may have a large influence on the ecosystem functioning.

Qarakhanids on the Edge of the Bukhara Oasis: Archaeobotany of Medieval Paykend

The urban center of Paykend was an exchange node just off the main corridor of the Silk Road in the Bukhara Oasis on the edge of the hyperarid Kyzyl–Kum Desert. The city was occupied from the end of 4 century B.C.E. to the mid–12 century C.E.; our study focuses on the Qarakhanid period (C.E. 999 – 1211), the last imperial phase of urban occupation at Paykend before its abandonment. In this study, we present the results of an analysis of archaeobotanical remains recovered from a multifunction rabat, which appears to have comprised a domicile, military structure, center of commerce, and/or a caravanserai, a roadside inn for travelers. We shed light on how people adapted a productive economy to the local ecological constraints. By adding these data to the limited Qarakhanid archaeobotany from across Central Asia, we provide the first glimpses into cultivation, commerce, and consumption at a Silk Road trading town along the King’s Road, the central artery of ancient Eurasia.

The conserved serine transporter SdaC moonlights to enable self recognition

Cells can use self recognition to achieve cooperative behaviors. Self-recognition genes are thought to principally evolve in tandem with partner self-recognition alleles. However, other constraints on protein evolution could exist. Here, we have identified an interaction outside of self-recognition loci that could constrain the sequence variation of a self-recognition protein. We show that during collective swarm expansion in Proteus mirabilis , self-recognition signaling co-opts SdaC, a serine transporter. Serine uptake is crucial for bacterial survival and colonization. Single-residue variants of SdaC reveal that self recognition requires an open conformation of the protein; serine transport is dispensable. A distant ortholog from Escherichia coli is sufficient for self recognition; however, a paralogous serine transporter, YhaO, is not. Thus, SdaC couples self recognition and serine transport, likely through a shared molecular interface. Self recognition proteins may follow the framework of a complex interaction network rather than an isolated two-protein system. Understanding molecular and ecological constraints on self-recognition proteins lays the groundwork for insights into the evolution of self recognition and emergent collective behaviors. Importance Bacteria can receive secret messages from kin during migration. For Proteus mirabilis , these messages are necessary for virulence in multi-species infections. We show that a serine transporter—conserved among gamma-enterobacteria– enables self recognition. Molecular co-option of nutrient uptake could limit the sequence variation of these message proteins. SdaC is the primary transporter for L-serine, a vital metabolite for colonization during disease. Unlike many self-recognition receptors, SdaC is sufficiently conserved between species to achieve recognition. The predicted open conformation is shared by transport and recognition. SdaC reveals the interdependence of communication and nutrient acquisition. As the broader interactions of self-recognition proteins are studied, features shared among microbial self-recognition systems, such as Dictyostelium spp. and Neurospora spp., could emerge.