Audrey L. Mayer

The Dynamic Regime Concept for Ecosystem Management and Restoration

Abstract Because the response of ecosystem patterns and processes to disturbance is rarely linear, the dynamic regime concept offers a more realistic construct than linear models for understanding ecosystems. Dynamic regimes, and shifts between them, have been reported for a diversity of ecosystem types (e.g., terrestrial, marine, aquatic) at a variety of scales (e.g., from small lakes to the global climate). Ecosystem regimes that are obvious at one scale may not be at another. Regimes are maintained by internal relationships and feedbacks between species, and these internal dynamics can interact with large-scale external forces (such as global weather patterns) and trigger shifts to alternative regimes. The dynamic regime concept is commonly used in ecosystem management, restoration, and sustainability efforts, in what are known as “state-and-transition,” “threshold,” or “alternative stable state” models. Here we review the application of this concept to ecosystem management and restoration, and discuss how dynamic processes at multiple scales can affect this application.

Grass Trumps Trees with Fire

Feedbacks involving rainfall, fire, and vegetation govern transitions between forests, savannas, and grasslands. Ecologists have long assumed that forests, savannas, and grasslands change gradually over space and time, with tree cover responding linearly to gradients in precipitation, aridity, fire disturbance, and grazing pressure. However, a growing body of evidence suggests that these biomes are self-reinforcing and that transitions between them can be nonlinear, governed by feedbacks at local and regional scales (1–3). Two reports in this issue, by Staver et al. on page 230 (4) and by Hirota et al. on page 232 (5), find evidence for these feedbacks and transitions at the global scale. These results suggest that global climate change will be substantially influenced by nonlinear behaviors and feedbacks between biophysical and human systems.

The multidisciplinary influence of common sustainability indices

Sustainability is often poorly defined and difficult to measure. We describe several concepts from ecology, economics, and physics, that have contributed to sustainability indices, and discuss their positive and negative aspects. Indices range from mostly ecological (such as ecosystem resilience and global human carrying capacity), to those inspired by both economics and ecology (green income and maximum sustainable yield), to a mix of ecology and physics (exergy and emergy). Economic concepts such as substitutability of natural and human capital (the “weak” versus “strong” sustainability debate), and throughput of natural resources through an economic system, are the basis for several strictly economic indices. The second law of thermodynamics, which dictates the decrease in usable energy, has also had an increasing influence on sustainability discussions. The indices described here address different aspects of the interactions between human societies and ecosystems, and are therefore probably most effec...

How Much Is Enough? Minimal Responses of Water Quality and Stream Biota to Partial Retrofit Stormwater Management in a Suburban Neighborhood

Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km2 Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007–2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots). Further research is needed to define the minimum effect threshold and restoration trajectories for retrofitting catchments to improve the health of stream ecosystems.

Family‐friendly policies and gender bias in academia

Several recent reports on the status of women in US academic institutions have recommended more generous family policies to encourage and retain more women among academic staffs. Many of the policies suggested are modelled on those that have been in effect in Nordic countries for decades. The status of women among Finnish and Swedish academic staff ranks is examined, with the assumption that women should be better represented if family policies are a significant factor in advancement and retention. It is found that similar conditions for female academics exist in the US as in Nordic countries, suggesting that advancement may be more dependent upon prevailing social conditions and gender stereotypes.

Consideration of grain and extent in landscape studies of terrestrial vertebrate ecology

The choice of scale (both grain and extent) of a research project can directly affect the results of the project itself, and the comparability of those results to similar research. This paper reviews 149 self-described landscape studies published between 1987 and 2001. From each paper, data for several variables were gathered that we proposed may influence the choice of scale. These variables included the taxa the research considered, the characteristics of the landscape of interest, the species response variables measured, the type of methodology employed by the study, the habitat type(s) surveyed, and the technique(s) used to create habitat maps. Our results demonstrated that only 61% of the papers identified both the grain and extent at which the research was conducted. Taxonomic group, landscape characteristics, and study type all appeared to influence both the choice of grain and extent for the study. Wide variation (standard deviation) in grain and extent among studies suggests that researchers either used some factor not considered here to select scale, or made decisions of the scale on pragmatic grounds, rather than on the appropriateness of the scale to the variables. Finally, 24 of the 149 studies reviewed researched the same combination of categories of the six variables that we considered, yet only for one combination was the grain and extent used within the same order of magnitude. This review highlights the need for more structured choice of scale in landscape studies, and in particular the need for more standardized size of grain and extent for greater comparability among studies.

ENVIRONMENTAL REVIEWS AND CASE STUDIES: Building Green Infrastructure via Citizen Participation: A Six-Year Study in the Shepherd Creek (Ohio)

Green infrastructure at the parcel scale provides critical ecosystem goods and services when these services (such as flood mitigation) must be provided locally. Here we report on an approach that encourages suburban landowners to mitigate impervious surfaces on their properties through a voluntary auction mechanism. We used an economic incentive to place rain gardens and rain barrels onto parcels in a 1.8-km2 watershed near Cincinnati, Ohio. A comprehensive hydrologic, water-quality, and ecological monitoring campaign documented environmental conditions before and after treatment. In 2007 and 2008, we engaged private landowners through a reverse auction to encourage placement of one rain garden and up to four rain barrels on their property. The program led to the installation of 83 rain gardens and 176 rain barrels onto more than 20% of the properties, and preliminary analyses indicate that the overall discharge regime was altered by the treatments. The length of the study (six years) may have precluded observation of treatment effects on water quality and aquatic biological communities, as we would expect these conditions to respond more slowly to management changes. These distributed storm-water installations contributed to ecosystem services such as flood protection, water supply, and water infiltration; provided benefits to the local residents; and reduced the need for larger, expensive, centralized retrofits (such as deep tunnel storage).

Use of the participatory approach to develop sustainability assessments for natural resource management

Monitoring progress toward sustainability goals requires a quantitative assessment method including indicators. Indicator sets and goals have typically been developed by experts, which may be scientifically robust but are often difficult to convey to society and may not include all societal values. A participatory assessment approach is emerging as a more holistic method for measuring sustainability. In this approach, local stakeholders play an integral part in the assessment process, assisted by experts. Here we reviewed 13 case studies from around the world that use a participatory approach to achieve sustainable natural resource management. Although similar in approach, most of them diverge in terms of methodology and extent of community engagement. The final set of indicators in each case is reflective of methodology, extent of community engagement, and amount of time and resources involved in the process. While the participatory approach is growing in popularity and increases the potential long-term success of the process (through increasing stakeholder literacy and ownership), the diversity of participatory methodology can complicate policy recommendations.

Information and entropy theory for the sustainability of coupled human and natural systems

For coupled human and natural systems (CHANS), sustainability can be defined operationally as a feasible, desirable set of flows (material, currency, information, energy, individuals, etc.) that can be maintained despite internal changes and changes in the environment. Sustainable development can be defined as the process by which CHANS can be moved toward sustainability. Specific indicators that give insight into the structure and behavior of feedbacks in CHANS are of particular interest because they would aid in the sustainable management of these systems through an understanding of the structures that govern system behavior. However, the use of specific feedbacks as monitoring tools is rare, possibly because of uncertainties regarding the nature of their dynamics and the diversity of types of feedbacks encountered in these systems. An information theory perspective may help to rectify this situation, as evidenced by recent research in sustainability science that supports the use of unit-free measures such as Shannon entropy and Fisher information to aggregate disparate indicators. These measures have been used for spatial and temporal datasets to monitor progress toward sustainability targets. Here, we provide a review of information theory and a theoretical framework for studying the dynamics of feedbacks in CHANS. We propose a combination of information-based indices that might productively inform our sustainability goals, particularly when related to key feedbacks in CHANS.

Use of Remote Sensing to Support Forest and Wetlands Policies in the USA

Abstract: The use of remote sensing for environmental policy development is now quite common and well-documented, as images from remote sensing platforms are often used to focus attention on emerging environmental issues and spur debate on potential policy solutions. However, its use in policy implementation and evaluation has not been examined in much detail. Here we examine the use of remote sensing to support the implementation and enforcement of policies regarding the conservation of forests and wetlands in the USA. Specifically, we focus on the “Roadless Rule” and “Travel Management Rules” as enforced by the US Department of Agriculture Forest Service on national forests, and the “No Net Loss” policy and Clean Water Act for wetlands on public and private lands, as enforced by the US Environmental Protection Agency and the US Army Corps of Engineers. We discuss several national and regional examples of how remote sensing for forest and wetland conservation has been effectively integrated with policy decisions, along with barriers to further integration. Some of these barriers are financial and technical (such as the lack of data at scales appropriate to policy enforcement), while others are political.