Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

Cognitive agency in sociocultural evolution

Models of sociocultural evolution generally study the population dynamics of cultural traits given known biases in social learning. Cognitive agency, understood as the dynamics underlying a specific agent’s adoption of a given trait, is essentially irrelevant in this framework. This article argues that although implementing and instrumenting agency in computational models is fundamentally challenging, it is ultimately possible and would help us overcome major limitations in our understanding of sociocultural dynamics.Indeed, the behaviour of humans is not causally generated by a set of predefined behavioural laws, but by the situated activity of their cognitive architecture. Idealised models of biased transmission certainly help us understand specific features of population dynamics. However, they distract us from the deep intrication of the cognitive and ecological processes underlying sociocultural evolution, and erase their embodied, subjective nature.In line with the earlier “Thinking Through Other Minds” account of sociocultural evolution, this article highlights how the Active Inference framework can help us implement and instrument computational models that address these limitations. Such models would not only help ground our understanding of sociocultural evolution in the underlying cognitive dynamics, but also help solve (or frame) open questions in the study of ritual, relation between cultural transmission and innovation, as well as scales of cultural evolution.

Selecting the optimal fine-scale historical climate data for assessing current and future hydrological conditions

High-resolution historical climate grids are readily available and frequently used as inputs for a wide range of regional management and risk assessments including water supply, ecological processes, and as baseline for climate change impact studies that compare them to future projected conditions. Because historical gridded climates are produced using various methods, their portrayal of landscape conditions differ, which becomes a source of uncertainty when they are applied to subsequent analyses. Here we tested the range of values from five gridded climate datasets. We compared their values to observations from 1,231 weather stations, first using each dataset’s native scale, and then after each was rescaled to 270-meter resolution. We inputted the downscaled grids to a mechanistic hydrology model and assessed the spatial results of six hydrological variables across California, in 10 ecoregions and 11 large watersheds in the Sierra Nevada. PRISM was most accurate for precipitation, ClimateNA for maximum temperature, and TopoWx for minimum temperature. The single most accurate dataset overall was PRISM due to the best performance for precipitation and low air temperature errors. Hydrological differences ranged up to 70% of the average monthly streamflow with an average of 35% disagreement for all months derived from different historical climate maps. Large differences in minimum air temperature data produced differences in modeled actual evapotranspiration, snowpack, and streamflow. Areas with the highest variability in climate data, including the Sierra Nevada and Klamath Mountains ecoregions, also had the largest spread for Snow Water Equivalent (SWE), recharge and runoff.

Family Legacy: Depicting Diversity-Elevation Relationships of Tropical Tree Communities

Unveiling the ecological processes driving diversity and its relationship to the environment remains a central goal in ecological studies. Here, we investigated the elevation effect on plant diversity patterns of tropical rainforests, using beta-, phylogenetic and alpha diversities. To do so, we compiled a forest dataset with 22,236 trees (DBH ≥ 4.8 cm) from 17 plots of 1 ha each along an elevational gradient (0 – 1,200 m a.s.l) in the Atlantic Forest of Southeastern Brazil. We found high phylogenetic and species rates of turnover – beta-diversity - along the elevational gradient. Alpha phylodiversity showed a monotonic decrease with increasing elevation, including or not fern species (a distantly related clade usually ignored in tropical ecology studies), while the phylogenetic structure was highly affected by the inclusion of fern trees. Species diversity showed a unimodal pattern for the whole community, and different patterns for the richest families. The diversity pattern of the whole community emerges from differences among species distribution of the richest families, while phylogenetic diversity seems to be gradually filtered by elevation. At intermediate elevations, higher species diversification within families might have led to different strategies and cooccurrence in tropical rainforests. We also showed that intricate effects of elevation in species assemblages can be better assessed using both ecological and evolutionary approaches, stressing the importance of species selection in diversity analyzes. Finally, we demonstrate that elevation has different effects on the species distributions of the richest families and warn that these differences should be considered in conservation planning.

Sustained coral reef growth in the critical wave dissipation zone of a Maldivian atoll

Sea-level rise is expected to outpace the capacity of coral reefs to grow and maintain their wave protection function, exacerbating coastal flooding and erosion of adjacent shorelines and threatening coastal communities. Here we present a new method that yields highly-resolved direct measurements of contemporary reef accretion on a Maldivian atoll reef rim, the critical zone that induces wave breaking. Results incorporate the suite of physical and ecological processes that contribute to reef accumulation and show growth rates vary from 6.6 ± 12.5 mm.y−1 on the reef crest, and up to 3.1 ± 10.2 mm.y−1, and −0.5 ± 1.8 mm.yr−1 on the outer and central reef flat respectively. If these short-term results are maintained over decades, the reef crest could keep pace with current sea-level rise. Findings highlight the need to resolve contemporary reef accretion at the critical wave dissipation zone to improve predictions of future reef growth, and re-evaluate exposure of adjacent shorelines to coastal hazards.

Coupling Human and Natural Systems for Sustainability: Experiences from China’s Loess Plateau

Addressing the sustainability challenges facing humanity in the Anthropocene requires the coupling of human and natural systems, rather than their separate treatment. To understand the dynamics of a coupled human and natural system (CHANS) and promote its sustainability, we proposed a conceptual cascade framework of “Pattern-Process-Service-Sustainability”. The use of this framework was systematically illustrated by a review of CHANS research experiences in China’s Loess Plateau (LP) in terms of coupling landscape patterns and ecological processes, linking ecological processes to services, and promoting social-ecological sustainability. The LP is well-known for its historically notorious soil erosion and successful vegetation restoration achieved in recent decades. Vegetation coverage in the LP has increased since 2000 due to ecological restoration. Soil erosion has been well controlled and the sediment deriving from the LP, and flowing into the Yellow River, has greatly decreased; however, overplanting, the introduction of exotic plant species, and the mismanagement of planted vegetation have also led to soil drying in some areas. Ecosystem services, especially for soil conservation and carbon sequestration, have significantly improved, although a trade-off between carbon sequestration and water supply has been identified at multiple scales. Based on the comprehensive understanding of CHANS dynamics, targeted policy and management suggestions are here proposed to support the social-ecological sustainability of the LP. The research experience accumulated on the LP offers examples of the application of the “Pattern-Process-Service-Sustainability” framework. Future research using this framework should especially examine the integrated research of multiple processes, the cascades of ecosystem structure, function, services, and human-wellbeing, the feedback mechanisms of human and natural systems, and the data and models for sustainability.

Evolutionary Ecology of Natural Comammox Nitrospira Populations

Microbial species interact with each other and their environment (ecological processes) and undergo changes in their genomic repertoire over time (evolutionary processes). How these two classes of processes interact is largely unknown, especially for complex communities, as most studies of microbial evolutionary dynamics consider single species in isolation or a few interacting species in simplified experimental systems.

Habitat Adaptation Drives Speciation of a Streptomyces Species with Distinct Habitats and Disparate Geographic Origins

Both isolation by distance and isolation by environment occur in bacteria, and different diversification patterns may apply to different species. Streptomyces species, typified by producing useful natural products, are widespread in nature and possess high genetic diversity. However, the ecological processes and evolutionary mechanisms that shape their distribution are not well understood.

Linking the effects of plant protection products on biodiversity and ecological processes to potential impairment of ecosystem functions and services—A multidisciplinary conceptual framework.

There is growing interest in using the ecosystem services framework for environmental risk assessments of plant protection products (PPP). However, there is still a broad gap between most of the ecotoxicological endpoints used in PPP risk assessment and the evaluation of the risks and effects of PPP on ecosystem services. Here we propose a conceptual framework to link current and future knowledge on the ecotoxicological effects of PPP on biodiversity and ecological processes to their consequences on ecosystem functions and services. We first describe the main processes governing the relationships between biodiversity, ecological processes and ecosystem functions in response to effects of PPP. We define 12 main categories of ecosystem functions that could be directly linked with the ecological processes used as functional endpoints in investigations on the ecotoxicology of PPP. An exploration of perceptions on the possible links between these categories of ecosystem functions and groups of ecosystem services (by a panel scientific experts in various fields of environmental sciences) then finds that these direct and indirect linkages still need clarification. We illustrate how the proposed framework could be used on terrestrial microalgae and cyanobacteria to assess the potential effects of herbicides on ecosystem services. The framework proposed here uses a set of clearly-defined core categories of ecosystem functions and services, which should help identify which of them are effectively or potentially threatened by PPP. We argue that this framework could help harmonize and extend the scientific knowledge that informs decision-making and policy-making.

Geochemical characterization of clastic sediments sheds light on energy sources and on alleged anthropogenic impacts in cave ecosystems

Caves are usually oligotrophic ecosystems, where the organic matter represents a limiting factor to the hypogeal community and sediments are often a significant energy source. With a view to identifying the energy input influencing the ecological processes occurring in caves, as well as the potential alteration sources of the natural equilibriums, geochemical features of several typologies of clastic sediments from the Pertosa-Auletta Cave (Italy) were investigated. The collected sediments, analyzed for a number of chemical (organic matter, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Si, Sr, Ti, V, Zn concentrations) and mineralogical (quartz, calcite, dolomite, clay minerals) characteristics, showed a different composition. Overall, their origin is supposed to be allochthonous, related to the important fluviokarst activities interesting the cave in the past, whereas the abundance of calcitic and dolomitic compounds can be autochthonous, being the carbonate the main host rock. The highest concentrations of organic matter, together with C, Cu, Mo, N, P, Pb, S and Zn, highlighted in one sample composed mainly of bats guano, revealed an important bioavailable energy input as well as a pollutant accumulation, mainly of anthropogenic origin.