Showing papers in "Frontiers in Ecology and the Environment in 2014"

Managing the whole landscape: historical, hybrid, and novel ecosystems

Abstract: The reality confronting ecosystem managers today is one of heterogeneous, rapidly transforming landscapes, particularly in the areas more affected by urban and agricultural development. A landscape management framework that incorporates all systems, across the spectrum of degrees of alteration, provides a fuller set of options for how and when to intervene, uses limited resources more effectively, and increases the chances of achieving management goals. That many ecosystems have departed so substantially from their historical trajectory that they defy conventional restoration is not in dispute. Acknowledging novel ecosystems need not constitute a threat to existing policy and management approaches. Rather, the development of an integrated approach to management interventions can provide options that are in tune with the current reality of rapid ecosystem change.

Conserving mobile species

Abstract: The distributions of many species are dynamic in space and time, and movements made by individuals range from regular and predictable migrations to erratic, resource-driven nomadism. Conserving such mobile species is challenging; the effectiveness of a conservation action taken at one site depends on the condition of other sites that may be geographically and politically distant (thousands of kilometers away or in another jurisdiction, for example). Recent work has shown that even simple and predictable linkages among sites caused by “to-and-fro” migration can make migratory species especially vulnerable to habitat loss, and substantially affect the results of conservation prioritizations. Species characterized by more erratic or nomadic movements are very difficult to protect through current conservation planning techniques, which typically view species distributions as static. However, collaborations between migration ecologists, conservation planners, and mathematical ecologists are paving the way for improvements in conservation planning for mobile species.

Farmland abandonment: threat or opportunity for biodiversity conservation? A global review

Abstract: Farmland abandonment is changing rural landscapes worldwide, but its impacts on biodiversity are still being debated in the scientific literature. While some researchers see it as a threat to biodiversity, others view it as an opportunity for habitat regeneration. We reviewed 276 published studies describing various effects of farmland abandonment on biodiversity and found that a study's geographic region, selected metrics, assessed taxa, and conservation focus significantly affected how those impacts were reported. Countries in Eurasia and the New World reported mainly negative and positive effects of farmland abandonment on biodiversity, respectively. Notably, contrasting impacts were recorded in different agricultural regions of the world that were otherwise similar in land-use and biodiversity characteristics. We showed that the conservation focus (pre- or post-abandonment) in different regions is an important factor influencing how scientists address the abandonment issue, and this may affect how lan...

Tracking the rapid loss of tidal wetlands in the Yellow Sea

Abstract: In the Yellow Sea region of East Asia, tidal wetlands are the frontline ecosystem protecting a coastal population of more than 60 million people from storms and sea-level rise. However, unprecedented coastal development has led to growing concern about the status of these ecosystems. We developed a remote-sensing method to assess change over ~4000 km of the Yellow Sea coastline and discovered extensive losses of the region's principal coastal ecosystem – tidal flats – associated with urban, industrial, and agricultural land reclamations. Our analysis revealed that 28% of tidal flats existing in the 1980s had disappeared by the late 2000s (1.2% annually). Moreover, reference to historical maps suggests that up to 65% of tidal flats were lost over the past five decades. With the region forecast to be a global hotspot of urban expansion, development of the Yellow Sea coastline should pursue a course that minimizes the loss of remaining coastal ecosystems.

From research to action: Enhancing crop yield through wild pollinators

Abstract: Recent evidence highlights the value of wild-insect species richness and abundance for crop pollination worldwide. Yet, deliberate physical importation of single species (eg European honey bees) into crop fields for pollination remains the mainstream management approach, and implementation of practices to enhance crop yield (production per area) through wild insects is only just beginning. With few exceptions, studies measuring the impacts of pollinator-supporting practices on wild-insect richness and pollination service success – particularly in relation to long-term crop yield and economic profit – are rare. Here, we provide a general framework and examples of approaches for enhancing pollinator richness and abundance, quantity and quality of pollen on stigmas, crop yield, and farmers' profit, including some benefits detected only through long-term monitoring. We argue for integrating the promotion of wild-insect species richness with single-species management to benefit farmers and society.

Ecological Homogenization of Urban USA

Abstract: A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial areas, and aquatic features. We hypothesize that this homogenization extends to ecological structure and also to ecosystem functions such as carbon dynamics and microclimate, with continental-scale implications. Further, we suggest that understanding urban homogenization will provide the basis for understanding the impacts of urban land-use change from local to continental scales. Here, we show how multi-scale, multi-disciplinary datasets from six metropolitan areas that cover the major climatic regions of the US (Phoenix, AZ; Miami, FL; Baltimore, MD; Boston, MA; Minneapolis–St Paul, MN; and Los Angeles, CA) can be used to determine how household and neighborhood characteristics correlate with land-management practices, land-cover composition, and landscape structure and ecosystem functions at local, regional, and continental scales.

The changing role of history in restoration ecology

Abstract: In the face of rapid environmental and cultural change, orthodox concepts in restoration ecology such as historical fidelity are being challenged. Here we re-examine the diverse roles played by historical knowledge in restoration, and argue that these roles remain vitally important. As such, historical knowledge will be critical in shaping restoration ecology in the future. Perhaps the most crucial role in shifting from the present version of restoration ecology (“v1.0”) to a newer formulation (“v2.0”) is the value of historical knowledge in guiding scientific interpretation, recognizing key ecological legacies, and influencing the choices available to practitioners of ecosystem intervention under conditions of open-ended and rapid change.

Bringing an ecological view of change to Landsat‐based remote sensing

Abstract: When characterizing the processes that shape ecosystems, ecologists increasingly use the unique perspective offered by repeat observations of remotely sensed imagery. However, the concept of change embodied in much of the traditional remote-sensing literature was primarily limited to capturing large or extreme changes occurring in natural systems, omitting many more subtle processes of interest to ecologists. Recent technical advances have led to a fundamental shift toward an ecological view of change. Although this conceptual shift began with coarser-scale global imagery, it has now reached users of Landsat imagery, since these datasets have temporal and spatial characteristics appropriate to many ecological questions. We argue that this ecologically relevant perspective of change allows the novel characterization of important dynamic processes, including disturbances, longterm trends, cyclical functions, and feedbacks, and that these improvements are already facilitating our understanding of critical driving forces, such as climate change, ecological interactions, and economic pressures.

Macrosystems ecology: understanding ecological patterns and processes at continental scales

Abstract: Macrosystems ecology is the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales. This emerging subdiscipline addresses ecological questions and environmental problems at these broad scales. Here, we describe this new field, show how it relates to modern ecological study, and highlight opportunities that stem from taking a macrosystems perspective. We present a hierarchical framework for investigating macrosystems at any level of ecological organization and in relation to broader and finer scales. Building on well-established theory and concepts from other subdisci- plines of ecology, we identify feedbacks, linkages among distant regions, and interactions that cross scales of space and time as the most likely sources of unexpected and novel behaviors in macrosystems. We present three examples that highlight the importance of this multiscaled systems perspective for understanding the ecology of regions to continents.

Environmental flows for natural, hybrid and novel riverine ecosystems in a changing world

Abstract: The term “environmental flows” describes the quantities, quality, and patterns of water flows required to sustain freshwater and estuarine ecosystems and the ecosystem services they provide. Environmental flows may be achieved in a number of different ways, most of which are based on either (1) limiting alterations from the natural flow baseline to maintain biodiversity and ecological integrity or (2) designing flow regimes to achieve specific ecological and ecosystem service outcomes. We argue that the former practice is more applicable to natural and semi-natural rivers where the primary objective and opportunity is ecological conservation. The latter “designer” approach is better suited to modified and managed rivers where return to natural conditions is no longer feasible and the objective is to maximize natural capital as well as support economic growth, recreation, or cultural history. This permits elements of ecosystem design and adaptation to environmental change. In a future characterized by altered climates and intensive regulation, where hybrid and novel aquatic ecosystems predominate, the designer approach may be the only feasible option. This conclusion stems from a lack of natural ecosystems from which to draw analogs and the need to support broader socioeconomic benefits and valuable configurations of natural and social capital.

Putting meaning back into “sustainable intensification”

Abstract: In light of human population growth, global food insecurity is an escalating concern. To meet increasing demand for food, leading scientists have called for “sustainable intensification”, defined as the process of enhancing agricultural yields with minimal environmental impact and without expanding the existing agricultural land base. We argue that this definition is inadequate to merit the term “sustainable”, because it lacks engagement with established principles that are central to sustainability. Sustainable intensification is likely to fail in improving food security if it continues to focus narrowly on food production ahead of other equally or more important variables that influence food security. Sustainable solutions for food security must be holistic and must address issues such as food accessibility. Wider consideration of issues related to equitable distribution of food and individual empowerment in the intensification decision process (distributive and procedural justice) is needed to put meaning back into the term “sustainable intensification”.

Whales as marine ecosystem engineers.

Abstract: Baleen and sperm whales, known collectively as the great whales, include the largest animals in the history of life on Earth. With high metabolic demands and large populations, whales probably had a strong influence on marine ecosystems before the advent of industrial whaling: as consumers of fish and invertebrates; as prey to other large-bodied predators; as reservoirs of and vertical and horizontal vectors for nutrients; and as detrital sources of energy and habitat in the deep sea. The decline in great whale numbers, estimated to be at least 66% and perhaps as high as 90%, has likely altered the structure and function of the oceans, but recovery is possible and in many cases is already underway. Future changes in the structure and function of the world's oceans can be expected with the restoration of great whale populations.

Temperate and boreal forest mega-fires: characteristics and challenges

Abstract: Mega-fires are often defined according to their size and intensity but are more accurately described by their socioeconomic impacts. Three factors – climate change, fire exclusion, and antecedent disturbance, collectively referred to as the “mega-fire triangle” – likely contribute to today's mega-fires. Some characteristics of mega-fires may emulate historical fire regimes and can therefore sustain healthy fire-prone ecosystems, but other attributes decrease ecosystem resiliency. A good example of a program that seeks to mitigate mega-fires is located in Western Australia, where prescribed burning reduces wildfire intensity while conserving ecosystems. Crown-fire-adapted ecosystems are likely at higher risk of frequent mega-fires as a result of climate change, as compared with other ecosystems once subject to frequent less severe fires. Fire and forest managers should recognize that mega-fires will be a part of future wildland fire regimes and should develop strategies to reduce their undesired impacts.

The nature, extent, and ecological implications of marine light pollution

Abstract: Despite centuries of use, artificial light at night has only recently been recognized as a cause for environmental concern. Its global extent and ongoing encroachment into naturally lit ecosystems has sparked scientific interest into the many ways in which it may negatively affect human health, societal attitudes, scientific endeavors, and biological processes. Yet, perhaps because sources of artificial light are largely land based, the potential for artificial light pollution to interfere with the biology of the ocean has not been explored in any detail. There is little information on how light pollution affects those species, behaviors, and interactions that are informed by the intensity, spectra, and periodicity of natural nighttime light in marine ecosystems. Here, we provide an overview of the extent of marine light pollution, discuss how it changes the physical environment, and explore its potential role in shaping marine ecosystems.

Riverine macrosystems ecology: sensitivity, resistance, and resilience of whole river basins with human alterations

Abstract: Riverine macrosystems are described here as watershed-scale networks of connected and interacting riverine and upland habitat patches. Such systems are driven by variable responses of nutrients and organisms to a suite of global and regional factors (eg climate, human social systems) interacting with finer-scale variations in geology, topography, and human modifications. We hypothesize that spatial heterogeneity, connectivity, and asynchrony among these patches regulate ecological dynamics of whole networks, altering system sensitivity, resistance, and resilience. Long-distance connections between patches may be particularly important in riverine macrosystems, shaping fundamental system properties. Furthermore, the type, extent, intensity, and spatial configuration of human activities (eg land-use change, dam construction) influence watershed-wide ecological properties through effects on habitat heterogeneity and connectivity at multiple scales. Thus, riverine macrosystems are coupled social–ecological sy...

Creating and maintaining high-performing collaborative research teams: the importance of diversity and interpersonal skills

Abstract: Collaborative research teams are a necessary and desirable component of most scientific endeavors. Effective collaborative teams exhibit important research outcomes, far beyond what could be accomplished by individuals working independently. These teams are made up of researchers who are committed to a common purpose, approach, and performance goals for which they hold themselves mutually accountable. We call such collaborations “high-performing collaborative research teams”. Here, we share lessons learned from our collective experience working with a wide range of collaborative teams and structure those lessons within a framework developed from literature in business, education, and a relatively new discipline, “science of team science”. We propose that high-performing collaborative research teams are created and maintained when team diversity (broadly defined) is effectively fostered and interpersonal skills are taught and practiced. Finally, we provide some strategies to foster team functioning and make recommendations for improving the collaborative culture in ecology.

Are large‐scale flow experiments informing the science and management of freshwater ecosystems?

Abstract: Greater scientific knowledge, changing societal values, and legislative mandates have emphasized the importance of implementing large-scale flow experiments (FEs) downstream of dams. We provide the first global assessment of FEs to evaluate their success in advancing science and informing management decisions. Systematic review of 113 FEs across 20 countries revealed that clear articulation of experimental objectives, while not universally practiced, was crucial for achieving management outcomes and changing dam-operating policies. Furthermore, changes to dam operations were three times less likely when FEs were conducted primarily for scientific purposes. Despite the recognized importance of riverine flow regimes, four-fifths of FEs involved only discrete flow events. Over three-quarters of FEs documented both abiotic and biotic outcomes, but only one-third examined multiple taxonomic responses, thus limiting how FE results can inform holistic dam management. Future FEs will present new opportunities to advance scientifically credible water policies.

Cross‐scale interactions: quantifying multi‐scaled cause–effect relationships in macrosystems

Abstract: Ecologists are increasingly discovering that ecological processes are made up of components that are multi-scaled in space and time. Some of the most complex of these processes are cross-scale interactions (CSIs), which occur when components interact across scales. When undetected, such interactions may cause errors in extrapolation from one region to another. CSIs, particularly those that include a regional scaled component, have not been systematically investigated or even reported because of the challenges of acquiring data at sufficiently broad spatial extents. We present an approach for quantifying CSIs and apply it to a case study investigating one such interaction, between local and regional scaled land-use drivers of lake phosphorus. Ultimately, our approach for investigating CSIs can serve as a basis for efforts to understand a wide variety of multi-scaled problems such as climate change, land-use/land-cover change, and invasive species.

Large-scale trade-off between agricultural intensification and crop pollination services

Abstract: Unprecedented growth in human populations has required the intensification of agriculture to enhance crop productivity, but this was achieved at a major cost to biodiversity. There is abundant local-scale evidence that both pollinator diversity and pollination services decrease with increasing agricultural intensification. This raises concerns regarding food security, as two-thirds of the world's major food crops are pollinator-dependent. Whether such local findings scale up and affect crop production over larger scales is still being debated. Here, we analyzed a country-wide dataset of the 54 major crops in France produced over the past two decades and found that benefits of agricultural intensification decrease with increasing pollinator dependence, to the extent that intensification failed to increase the yield of pollinator-dependent crops and decreased the stability of their yield over time. This indicates that benefits from agricultural intensification may be offset by reductions in pollination serv...

Do septic tank systems pose a hidden threat to water quality

Abstract: Aquatic ecosystems are being degraded by anthropogenic pollution on a global scale. Septic tank systems (STS), which are widely distributed in rural and peri-urban areas, are one potential source of water pollution. Although generally regarded as the most efficient method for onsite treatment of domestic wastewater, we question whether current regulation and management of these systems is sufficient to guarantee that they function effectively. Here, we present watershed-specific examples that illustrate some of the problems that arise when many years of inadequate regulation and management result in a legacy of failing STS that can become long-term, chronic sources of nutrient pollution. Our data suggest that more accurate accounting of the location, performance, and degree of failure of STS, and more research into their impacts on water quality, would improve source attribution of pollutants within rural watersheds. This would ensure that education of homeowners, mitigation, interdisciplinary research, and technological innovation could be targeted in a cost-effective way.

Increasing forest loss worldwide from invasive pests requires new trade regulations

Abstract: Loss of forests due to non-native invasive pests (including insects, nematodes, and pathogens) is a global phenomenon with profound population, community, ecosystem, and economic impacts. We review the magnitude of pest-associated forest loss worldwide and discuss the major ecological and evolutionary causes and consequences of these invasions. After compiling and analyzing a dataset of pest invasions from 21 countries, we show that the number of forest pest invasions recorded for a given country has a significant positive relationship with trade (as indicated by gross domestic product) and is not associated with the amount of forested land within that country. We recommend revisions to existing international protocols for preventing pest entry and proliferation, including prohibiting shipments of non-essential plants and plant products unless quarantined. Because invasions often originate from taxa that are scientifically described only after their introduction, current phytosanitary regulations – which ...

Improving the culture of interdisciplinary collaboration in ecology by expanding measures of success

Abstract: Interdisciplinary collaboration is essential to understand ecological systems at scales critical to human decision making. Current reward structures are problematic for scientists engaged in interdisciplinary research, particularly early career researchers, because academic culture tends to value only some research outputs, such as primary-authored publications. Here, we present a framework for the costs and benefits of collaboration, with a focus on early career stages, and show how the implementation of novel measures of success can help defray the costs of collaboration. Success measures at team and individual levels include research outputs other than publications, including educational outcomes, dataset creation, outreach products (eg blogs or social media), and the application of scientific results to policy or management activities. Promotion and adoption of new measures of success will require concerted effort by both collaborators and their institutions. Expanded measures should better reflect an...

Making connections in aquatic ecosystems with acoustic telemetry monitoring

Abstract: Autonomous acoustic telemetry monitoring systems have been deployed in aquatic ecosystems around the globe – from under ice sheets in the Arctic to coral reefs in Australia – to track animals With tens of thousands of tagged aquatic animals from a range of taxa, vast amounts of data have been generated As data accumulate, it is useful to reflect on how this information has advanced our understanding of aquatic animals and improved management and conservation Here we identify knowledge gaps and discuss opportunities to advance aquatic animal science and management using acoustic telemetry monitoring Current technological and analytical shortfalls still need to be addressed to fully realize the potential of acoustic monitoring Future interdisciplinary research that relies on transmitter-borne sensors and emphasizes hypothesis testing will amplify the benefits of this technology

Linking human well-being and jellyfish: ecosystem services, impacts and societal responses

Abstract: Jellyfish are usually perceived as harmful to humans and are seen as “pests”. This negative perception has hindered knowledge regarding their value in terms of ecosystem services. As humans increasingly modify and interact with coastal ecosystems, it is important to evaluate the benefits and costs of jellyfish, given that jellyfish bloom size, frequency, duration, and extent are apparently increasing in some regions of the world. Here we explore those benefits and costs as categorized by regulating, supporting, cultural, and provisioning ecosystem services. A geographical perspective of human vulnerability to jellyfish over four categories of human well-being (health care, food, energy, and freshwater production) is also discussed in the context of thresholds and trade-offs to enable social adaptation. Whereas beneficial services provided by jellyfish likely scale linearly with biomass (perhaps peaking at a saturation point), non-linear thresholds exist for negative impacts to ecosystem services. We suggest that costly adaptive strategies will outpace the beneficial services if jellyfish populations continue to increase in the future.

Reconciling conflicting perspectives for biodiversity conservation in the Anthropocene

Abstract: We introduce a framework – based on experiences from oceanic islands – for conserving biodiversity in the Anthropocene. In an increasingly human-dominated world, the context for conservation-oriented action is extremely variable, attributable to three largely independent factors: the degree of anthropogenic change, the importance of deliberate versus inadvertent human influence on ecosystems, and land-use priorities. Given this variability, we discuss the need to integrate four strategies, often considered incompatible, for safeguarding biodiversity: maintaining relicts of historical biodiversity through intensive and continuous management; creating artificial in situ, inter situ, and ex situ conservation settings that are resilient to anthropogenic change; co-opting novel ecosystems and associated “opportunistic biodiversity” as the wildlands of the future; and promoting biodiversity in cultural landscapes by adapting economic activities.

Placing unprecedented recent fir growth in a European‐wide and Holocene‐long context

Abstract: Forest decline played a pivotal role in motivating Europe's political focus on sustainability around 35 years ago. Silver fir (Abies alba) exhibited a particularly severe dieback in the mid-1970s, but disentangling biotic from abiotic drivers remained challenging because both spatial and temporal data were lacking. Here, we analyze 14 136 samples from living trees and historical timbers, together with 356 pollen records, to evaluate recent fir growth from a continent-wide and Holocene-long perspective. Land use and climate change influenced forest growth over the past millennium, whereas anthropogenic emissions of acidic sulfates and nitrates became important after about 1850. Pollution control since the 1980s, together with a warmer but not drier climate, has facilitated an unprecedented surge in productivity across Central European fir stands. Restricted fir distribution prior to the Mesolithic and again in the Modern Era, separated by a peak in abundance during the Bronze Age, is indicative of the long-term interplay of changing temperatures, shifts in the hydrological cycle, and human impacts that have shaped forest structure and productivity.

Land-use change: incorporating the frequency, sequence, time span, and magnitude of changes into ecological research

Abstract: The frequency and extent of human-induced land-cover changes is escalating worldwide. Recurrent turnover of land-cover types will affect ecosystems over and above major, one-time changes (eg deforestation). Here, we show how a deeper appreciation of the temporal dynamics of land-cover change is needed to understand its effects on ecosystems. We distinguish between four key components of land-change regimes: (1) frequency of land-cover changes over a period of time, (2) the sequence of land-cover types, (3) the time span over which each land-cover type extends, and (4) the magnitude of difference between land-cover types. We synthesize the impacts of these four components on ecological communities, showing that frequent land-cover changes are likely to favor species that are habitat and dietary generalists. Greater attention to the complex dynamics of land-cover changes is critical for a better understanding of the future impacts that human-generated land-use changes will have on global biodiversity.

Biotic impacts of energy development from shale: research priorities and knowledge gaps

Abstract: 11 Although shale drilling operations for oil and natural gas have increased greatly in the past decade, few studies directly quantify the impacts of shale development on plants and wildlife. We evaluate knowledge gaps related to shale development and prioritize research needs using a quantitative framework that includes spatial and tem- poral extent, mitigation difficulty, and current level of understanding. Identified threats to biota from shale development include: surface and groundwater contamination; diminished stream flow; stream siltation; habitat loss and fragmentation; localized air, noise, and light pollution; climate change; and cumulative impacts. We find the highest research priorities to be probabilistic threats (underground chemical migration; contaminant release during storage, during disposal, or from accidents; and cumulative impacts), the study of which will require major scientific coordination among researchers, industry, and government decision makers. Taken together, our research prioritization outlines a way forward to better understand how energy development affects the natural world.

Biofouling animals in fresh water: biology, impacts, and ecosystem engineering

Abstract: Biofoulers accumulate on underwater surfaces and adversely affect human activities and infrastructure. Freshwater biofoulers are much less well-known than their marine counterparts but can be economically important: we estimate the potential global cost of freshwater biofouling to be ~US$277 million per year. They include several groups of organisms, all of which have the potential to be ecosystem engineers with strong effects on the physical and chemical properties of freshwater habitats. Nevertheless, ecological and economic research on freshwater biofoulers has been limited. We predict that freshwater biofouling will become worse in the future as a result of human activities, such as anthropogenic introductions of exotic species, eutrophication, construction of artificial habitats, and climate change. Increasing demand for energy and water may raise the costs associated with freshwater biofouling prevention and damage repair. More research and better policies and technologies are needed to prevent esca...