Love darts are hard 'needles' that many snails and slugs use to pierce their partner during mating. In a few species, darts have been shown to play a role in sperm competition. Two new papers, by Davison et al., and Koene and Schulenburg, might further pique researchers' interest, because they show how the full potential of darts can be tapped for studies of sexual selection in hermaphrodites.
Tropical forests are highly diverse systems involving extraordinary numbers of interactions between species, with each species responding in a different way to the abiotic environment. Understanding how these systems function and predicting how they respond to anthropogenic global change is extremely challenging. We argue for the necessity of 'whole-ecosystem' experimental manipulations, in which the entire ecosystem is targeted, either to reveal the functioning of the system in its natural state or to understand responses to anthropogenic impacts. We survey the current range of whole-ecosystem manipulations, which include those targeting weather and climate, nutrients, biotic interactions, human impacts, and habitat restoration. Finally we describe the unique challenges and opportunities presented by such projects and suggest directions for future experiments.
We are in a new epoch, the Anthropocene, and research into our closest living relatives, the great apes, must keep pace with the rate that our species is driving change. While a goal of many studies is to understand how great apes behave in natural contexts, the impact of human activities must increasingly be taken into account. This is both a challenge and an opportunity, which can importantly inform research in three diverse fields: cognition, human evolution, and conservation. No long-term great ape research site is wholly unaffected by human influence, but research at those that are especially affected by human activity is particularly important for ensuring that our great ape kin survive the Anthropocene.
Zoonosis-based epidemics are inevitable unless we revisit our relationship with the natural world, protect habitats, and regulate wildlife trade, including live animals and non-sustenance products. To prevent future zoonoses, governments must establish effective legislation addressing wildlife trade, protection of habitats, and reduction of the wildlife-livestock-human interface.
We present the results of our tenth annual horizon scan. We identified 15 emerging priority topics that may have major positive or negative effects on the future conservation of global biodiversity, but currently have low awareness within the conservation community. We hope to increase research and policy attention on these areas, improving the capacity of the community to mitigate impacts of potentially negative issues, and maximise the benefits of issues that provide opportunities. Topics include advances in crop breeding, which may affect insects and land use; manipulations of natural water flows and weather systems on the Tibetan Plateau; release of carbon and mercury from melting polar ice and thawing permafrost; new funding schemes and regulations; and land-use changes across Indo-Malaysia.
Ecological effects of alien species can be dramatic, but management and prevention of negative impacts are often hindered by crypticity of the species or their ecological functions. Ecological functions can change dramatically over time, or manifest after long periods of an innocuous presence. Such cryptic processes may lead to an underestimation of long-term impacts and constrain management effectiveness. Here, we present a conceptual framework of crypticity in biological invasions. We identify the underlying mechanisms, provide evidence of their importance, and illustrate this phenomenon with case studies. This framework has potential to improve the recognition of the full risks and impacts of invasive species.
Recent advances in environmental analytical chemistry have identified the presence of a large number of chemicals of emerging Arctic concern (CEACs) being transported long range to the region. There has been very limited temporal monitoring of CEACs and it is therefore unknown whether they are of increasing or decreasing concern. Likewise, information on potential biological adverse effects from CEACs on Arctic wildlife is lacking compared with legacy persistent organic pollutants (POPs) found at levels associated with health effects in marine mammals. Hence, there is a need to monitor CEACs along with POPs to support risk and regulatory CEAC assessments. We suggest pan-Arctic temporal trend studies of CEACs in wildlife including the establishment of toxicity thresholds to evaluate their potential effects on populations, biodiversity, and ecosystem services.
The structure of ecological networks reflects the evolutionary history of their biotic components, and their dynamics are strongly driven by ecoevolutionary processes. Here, we present an appraisal of recent relevant research, in which the pervasive role of evolution within ecological networks is manifest. Although evolutionary processes are most evident at macroevolutionary scales, they are also important drivers of local network structure and dynamics. We propose components of a blueprint for further research, emphasising process-based models, experimental evolution, and phenotypic variation, across a range of distinct spatial and temporal scales. Evolutionary dimensions are required to advance our understanding of foundational properties of community assembly and to enhance our capability of predicting how networks will respond to impending changes.
Forest canopies are dynamic interfaces between organisms and atmosphere, providing buffered microclimates and complex microhabitats. Canopies form vertically stratified ecosystems interconnected with other strata. Some forest biodiversity patterns and food webs have been documented and measurements of ecophysiology and biogeochemical cycling have allowed analyses of large-scale transfer of CO2, water, and trace gases between forests and the atmosphere. However, many knowledge gaps remain. With global research networks and databases, and new technologies and infrastructure, we envisage rapid advances in our understanding of the mechanisms that drive the spatial and temporal dynamics of forests and their canopies. Such understanding is vital for the successful management and conservation of global forests and the ecosystem services they provide to the world.
Development of new biocides has dominated human responses to evolution of antibiotic and pesticide resistance. Increasing and uniform biocide use, the spread of resistance genes, and the lack of new classes of compounds indicate the importance of navigating toward more sustainable coevolutionary dynamics between human culture and species that evolve resistance. To inform this challenge, we introduce the concept of coevolutionary governance and propose three priorities for its implementation: (i) new norms and mental models for lowering use, (ii) diversifying practices to reduce directional selection, and (iii) investment in collective action institutions to govern connectivity. We highlight the availability of solutions that facilitate broader sustainable development, which for antibiotic resistance include improved sanitation and hygiene, strong health systems, and decreased meat consumption.
The Belt and Road Initiative (BRI) represents the largest infrastructure and development project in human history, and presents risks and opportunities for ecosystems, economies, and communities. Some risks (habitat fragmentation, roadkill) are obvious, however, many of the BRI's largest challenges for development and conservation are not obvious and require extensive consideration to identify. In this first BRI Horizon Scan, we identify 11 frontier issues that may have large environmental and social impacts but are not yet recognised. More generally, the BRI will increase China's participation in international environmental governance. Thus, new cooperative modes of governance are needed to balance geopolitical, societal, and environmental interests. Upgrading and standardising global environmental standards is essential to safeguard ecological systems and human societies.
The numerous explanations for why Earth's biodiversity is concentrated at low latitudes fail to explain variation in the strength and even direction of the gradient through deep time. Consequently, we do not know if today's gradient is representative of what might be expected on other planets or is merely an idiosyncrasy of Earth's history. We propose a hierarchy of factors driving the latitudinal distribution of diversity: (i) over geologically long time spans, diversity is largely predicted by climate; (ii) when climatic gradients are shallow, diversity tracks habitat area; and (iii) historical contingencies linked to niche conservatism have geologically short-term, transient influence at most. Thus, latitudinal diversity gradients, although variable in strength and direction, are largely predictable on our planet and possibly others.
Climate change is causing species ranges to shift, expand, and contract, with divergent and underappreciated consequences for local and global biodiversity. Widespread range shifts should increase local diversity in most areas but reduce it in the tropical lowlands. Widespread expansions should maintain diversity at low latitudes while increasing diversity elsewhere, leading to stable global biodiversity. Expansions and shifts are both common responses to climate change now and in the deep past. To understand how changing ranges will reshape Earth's biodiversity, we argue for three research directions: (i) leverage paleontological data to reveal long-term biodiversity responses, (ii) better monitor low-elevation and latitude limits to distinguish shifts from expansions, and (iii) incorporate dispersal barriers that can turn would-be shifts into contractions and extinctions.
Introducing new genes and new species into ecosystems where they have not previously existed presents opportunities and complex, multivalue decisions for conservation biologists and the public. Both synthetic biology and conservation introductions offer potential benefits, such as avoiding extinctions and restoring ecological function, but also carry risks of unintended ecological consequences and raise social and moral concerns. Although the conservation community has attempted to establish guidelines for each new tool, there is a need for comprehensive principles that will enable conservation managers to navigate emerging technologies. Here, we combine biological, legal, social, cultural, and ethical considerations into an inclusive set of principles designed to facilitate the efforts of managers facing high-consequence conservation decisions by clarifying the stakes of inaction and action, along with the use of decision frameworks to integrate multiple considerations.