Resource Database

Trophic Cascades in Yellowstone: The First 15 Years after Wolf Reintroduction

Synthesis results generally indicate that the reintroduction of wolves restored a trophic cascade with woody browse species growing taller and canopy cover increasing in some, but not all places. After wolf reintroduction, elk populations decreased, but both beaver (Caster canadensis) and bison (Bison bison) numbers increased, possibly due to the increase in available woody plants and herbaceous forage resulting from less competition with elk. Trophic cascades research during the first 15 years after wolf reintroduction indicated substantial initial effects on both plants and animals, but northern Yellowstone still appears to be in the early stages of ecosystem recovery. In ecosystems where wolves have been displaced or locally extirpated, their reintroduction may represent a particularly effective approach for passive restoration.

Understanding and Planning Ecological Restoration of Plant–Pollinator Networks

Theory developed from studying changes in the structure and function of communities during natural or managed succession can guide the restoration of particular communities. We constructed 30 quantitative plant–flower visitor networks along a managed successional gradient to identify the main drivers of change in network structure. We then applied two alternative restoration strategies in silico (restoring for functional complementarity or redundancy) to data from our early successional plots to examine whether different strategies affected the restoration trajectories. Changes in network structure were explained by a combination of age, tree density and variation in tree diameter, even when variance explained by undergrowth structure was accounted for first. A combination of field data, a network approach and numerical simulations helped to identify which species should be given restoration priority in the context of different restoration targets. This combined approach provides a powerful tool for directing management decisions, particularly when management seeks to restore or conserve ecosystem function.

Understanding Restoration Volunteering in a Context of Environmental Change: In Pursuit of Novel Ecosystems or Historical Analogues?

By focusing on (the politics of) knowledge, our approach draws attention to the relationship between volunteers and scientists engaged in ecological restoration. Volunteers are not only the workers whom scientists ask to carry out various activities without requiring much understanding or input and critical engagement. They also bring in different social values and are a source of local knowledge and insights. A critical political ecology perspective also argues that there is a need for “greater public participation in the formulation of environmental science” and that ecological science is no longer to be viewed as the singular and neutral source of information that informs policymakers.

When is Open-endedness Desirable in Restoration Projects?

A low-intervention approach to restoration that also allows restoration outcomes to be framed as trajectories of ecosystem change can be described as “open-ended” restoration. It is an approach which recognizes that long-term ecosystem behavior involves continual change at small and large spatial and temporal scales. There are a number of situations in which it is appropriate to adopt an open-ended approach to restoration including: in remote and large areas, where ecological limiting factors will be changed by future climates, where antecedent conditions cannot be replicated, where there are novel starting points for restoration, where restoration relies strongly on processes outside the restoration area, in inherently dynamic systems, where costs are high and where the public demands “wildness.” Where this approach is adopted managers need to explain the project and deal with public expectations and public risk. Monitoring biotic and abiotic components of the project are very important as an open- ended approach does not equate to “abandon and ignore it.”

Whole-island Carbon Stocks in the Tropical Pacific: Implications for Mangrove Conservation and Upland Restoration

Management of forest carbon (C) stocks is an increasingly prominent land-use issue. Knowledge of carbon storage in tropical forests is improving, but regional variations are still poorly understood, and this constrains forest management and conservation efforts associated with carbon valuation mechanisms (e.g., carbon markets). This deficiency is especially pronounced in tropical islands and low-lying coastal areas where climate change impacts are expected to be among the most severe. This study presents the first field estimate of island-wide carbon storage in ecosystems of Oceania, with special attention to the regional role of coastal mangroves, which occur on islands and coastal zones throughout the tropics. Sustainable management of mangrove forests and their large C stocks is of high importance at the regional scale, and climate change mitigation programs such as REDD+ could play a large role in avoiding deforestation of mangroves where this is a management objective.

Adaptive Management: The U.S. Department of the Interior Applications Guide

This applications guide builds on the framework of the DOI Adaptive Management Technical Guide (2007), which describes adaptive management in terms of learning-based management of natural resources. In this guide, we use case studies to show how adaptive management can be used for both management and learning. We focus on practical applications in the areas of importance to DOI managers – climate change, water, energy, and human impacts on the landscape. We present adaptive management as a form of structured decision making, with an emphasis on the value of reducing uncertainty over time in order to improve management. The first half of the guide covers the foundations and challenges of adaptive management, and the second half documents examples that illustrate the components of adaptive management.

Bases para la restauración ecológica de espartales

Special Issue: International Journal of Mediterranean Ecology

This special issue of ecologia mediterranea is part of the proceedings of the 7th SER European conference on ecological restoration which was held for the first time in France in the prestigious premises of the Palais des Papes International Conference Center in Avignon from 23 to 27 August 2010. The theme chosen “Ecological Restoration and Sustainable Development: Establishing Links Across Frontiers” is at the core of environmental concerns in Europe.

Species, Functional Groups and Community Structure in Seedbanks of the Arid Nama Karoo: Grazing Impacts and Implications for Rangeland Restoration

The regeneration potential of grazing-affected Nama Karoo vegetation was evaluated by comparing soil seed banks of different microsites across a fence-line contrast in arid Namibia. Seed banks under low and high grazing pressure reflected the condition of the standing vegetation in terms of composition, community structure and species abundance distributions. Results indicated an advanced divergence in the vegetation at the degraded site with seed banks of species common under sustainable grazing being drastically reduced. Their low abundance, even in safe sites, suggests that long-distance dispersal is one of the main limiting factors for natural re-establishment after disturbance. The inertia in recovery of Namibian degraded rangelands through seed limitation can be overcome only by active species introduction.

Stepping Up the Ambition for Carbon Management: A Vision for Carbon-rich, Cross- continental Biodiversity Corridors

We have the chance to create our own positive story of restoration on a grand scale. Managing land to store terrestrial carbon and provide biodiversity corridors is a strong linking thread through this narrative of hope. However, it must go hand-in-hand with stopping ongoing degradation (including halting deforestation), whether it is caused by economic development or poverty.

Storm-generated Fragments of the Seagrass Posidonia oceanica from Beach Wrack: A Potential Source of Transplants for Restoration

The use of fragments detached naturally from Posidonia oceanica, a threatened seagrass protected by European legislation, as non-destructive alternative to removing cuttings from donor meadows for restoration efforts has been recently proposed. A 4-year study was performed to investigate whether storm-generated fragments deposited on beaches can be salvaged and used as transplant source. Four months after collection, fragment survival was high (80–96%). Half of the fragments regenerated and survived as long as 3 years in tanks. Initial growth form and size were not predictors of fragment survival or regeneration probability. Division of fragments allowed doubling transplant number. One year after transplanting, 50% of the fragments on the artificial reef were still present and ca. half of them produced new shoots. This indicates that fragments retain the capacity to re-establish once reintroduced into the field and thus could represent a potentially important transplant source. The use of this material could have major advantages over traditional restoration techniques, including large availability with zero impact on existing populations and low collection efforts.

Successful Adaptive Management: The Integration of Research and Management

We argue that there are 2 strategies that can be used to improve the success of adaptive management. The first is to start with a simple adaptive management plan and then add complexity over time. The second is to include researchers in all stages of the process to benefit from their expertise in ecology, experimental design, and data analysis. Although adaptive management takes time, rewards include increased understanding of the system, a management program that is scientifically valid, and a management strategy tailored to a particular site. In this paper we briefly explain adaptive management and then offer a step-by- step process for developing and implementing adaptive management in small reserves or on private lands. We believe increased understanding of adaptive management will lead to its widespread use and will ensure that more people benefit from its strengths.

Successful Transplantation of a Fragmenting Coral, Montipora digitata, for Reef Rehabilitation

The scleractinian coral Montipora digitata (Acroporidae) is a common reef flat species that thrives under high levels of light and water turbulence, and propagates successfully by natural fragmentation. It was used for transplantation experiments in an attempt to restore a degraded lagoon environment in the northwestern Philippines. Branches about 5 cm high from a natural population in the lagoon were transplanted to dead coral outcrops or knolls in two locations (Binlab and Malilnep-Ac) with different environmental characteristics. These results demonstrate the potential of coral transplantation to initiate the establishment of natural communities in degraded reef areas, a concern for coastal managers in developing countries.

The Ecology and Ecosystem Services of Native Trees: Implications for Reforestation and Land Restoration in Mesoamerica

This Special Issue includes articles produced as the result of a conference held in Panama City, Panama in January 2010 with the goal to summarize the state of knowledge of native species reforestation and associated ecosystems services in Mesoamerica. The introduction concludes with a call for continued research, including a mechanistic understanding of tree interactions with the biophysical environment in order to advance or knowledge of ecosystem services and their interactions. Results from these and other studies aimed at socioeconomic aspects of reforestation are critical to land use planning.

The Impact of Peatland Restoration on the Site Hydrology of an Abandoned Block-Cut Bog

Artificial drainage networks established throughout peatlands during the peat extraction process often remain active following abandonment, maintaining a water table relatively far from the surface of the peat, and hindering the survival and reestablishment of Sphagnum mosses. As an initial restoration effort, the primary drainage network of an abandoned cutover peatland was blocked with a series of peat dams, consequently reducing the runoff efficiency and causing the site-average water table to rise by 32 cm. Changes to the system hydrology following restoration efforts produced hydrological conditions more favourable for the recolonization of Sphagnum mosses.

The Need for Flexibility in Conservation Practices: Exotic Species as an Example

To garner support for biodiversity from the World’s human population, conservation biologists need an open-minded, integrated conservation strategy. We suggest that this strategy should include efforts to (1) preserve existing high quality, diverse ecosystems, (2) remediate impaired systems, (3) balance the needs of people and ecological resources, and (4) engender appreciation of nature and its services. We refer to these four key tenets as reservation, restoration, reconciliation, and reconnection. We illustrate these concepts by presenting the debate surrounding the management of exotic species from an unusual perspective, the benefits of exotic species.

The Penobscot River, Maine, USA: A Basin-Scale Approach to Balancing Power Generation and Ecosystem Restoration

Although hydropower is a source of low-carbon energy, without careful consideration and management, dams have the potential to degrade river ecosystems and the goods and services they provide to society. Today, a broad range of hydropower interests and stakeholders are seeking approaches to hydropower development and operation that are more environmentally and socially sustainable. The Penobscot River Restoration Project (‘the Project’) illustrates that basin-scale approaches can provide a broader set of solutions for balancing energy and riverine environmental resources than can be achieved at the scale of individual projects.

The Restoration of Biodiversity: Where has Research Been and Where does it Need to Go?

The practice of ecological restoration is a primary option for increasing levels of biodiversity by modifying human-altered ecosystems. The scientific discipline of restoration ecology provides conceptual guidance and tests of restoration strategies, with the ultimate goal of predictive landscape restoration. I construct a conceptual model for restoration of biodiversity, based on site-level (e.g., biotic and abiotic) conditions, landscape (e.g, interpatch connectivity and patch geometry), and historical factors (e.g., species arrival order and land-use legacies). I then ask how well restoration ecology has addressed the various components of this model. During the past decade, restoration research has focused largely on how the restoration of site-level factors promotes species diversity—primarily of plants. Relatively little attention has been paid to how landscape or historical factors interplay with restoration, how restoration influences functional and genetic components of biodiversity, or how a suite of less-studied taxa might be restored.

The Restoration of Vegetation Cover in the Semi-Arid Iberian Southeast

Here, we review recent advances in the restoration of semiarid vegetation cover in the Iberian southeast, discuss future challenges and suggest two key steps towards increasing the consistency and efficiency of restoration programs: emphasis on ecosystem services, and implementation of participative and adaptive management practices.

The Restorative Imperative: Assessing Objectives, Approaches and Challenges to Restoring Naturalness in Forests

The inherent challenges in restoring “naturalness” include high temporal and spatial heterogeneity in forest conditions and natural disturbances, the long history of human influence on forests in many regions of the world, and uncertainty about future climate and disturbance regimes. Although fixed templates may be inappropriate, we still have a reasonably clear idea of the incremental steps required to make forests more natural. Because most locations can support many alternative configurations of natural vegetation, the restoration of forest naturalness necessarily involves the setting of priorities and strategic directions in the context of human values and objectives, as informed by our best understanding of ecosystem structure and function now and in the future.

The Role of Botanic Gardens in the Science and Practice of Ecological Restoration

Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the world’s botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant-based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science-based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange.

The Roles of Exotic Grasses and Forbs when Restoring Native Species to Highly Invaded Southern California Annual Grassland

A 3-year experiment in southern California coastal sage scrub (CSS) now dominated by exotic grasses was done to investigate the influence of both exotic grasses (mainly Bromus spp.) and exotic forbs (mainly Erodium spp.) on a restoration seeding (9 species, including grasses, forbs, and shrubs). Experimental plots were weeded to remove one, both, or neither group of exotic species and seeded at a high rate with a mix of native species. Abundance of all species varied with precipitation levels, but seeded species established best when both groups of exotic species were removed. The removal of exotic grasses resulted in an increase in exotic and native forb cover, while removal of exotic forbs led to an increase in exotic grass cover and, at least in one year, a decrease in native forb cover. Therefore, management of CSS and exotic grassland in southern California and similar areas must consider control of both exotic grasses and forbs when restoration is attempted.

The Sabah Biodiversity Experiment: A Long-term Test of the Role of Tree Diversity in Restoring Tropical Forest Structure and Functioning

Relatively, little is known about the relationship between biodiversity and ecosystem functioning in forests, especially in the tropics. We describe the Sabah Biodiversity Experiment: a large-scale, long-term field study on the island of Borneo. The project aims at understanding the relationship between tree species diversity and the functioning of lowland dipterocarp rainforest during restoration following selective logging. The experiment is planned to run for several decades (from seed to adult tree), so here we focus on introducing the project and its experimental design and on assessing initial conditions and the potential for restoration of the structure and functioning of the study system, the Malua Forest Reserve. Our results establish the initial conditions for the Sabah Biodiversity Experiment and confirm the potential to accelerate restoration by using enrichment planting of dipterocarps to overcome recruitment limitation. What role dipterocarp diversity plays in restoration only will become clear with long- term results.

The Tree Planting and Protecting Culture of Cattle Ranchers and Small-scale Agriculturalists in Rural Panama: Opportunities for Reforestation and Land Restoration

To examine the opportunities available for designing diverse tree planting and land restoration initiatives in agricultural landscapes that contain tropical dry forests, the tree planting and protecting practices of cattle ranchers and small-scale agriculturalists were examined in two study sites in rural Panama. Ninety-nine tree species were identified that they utilize, plant, or protect on their land, the majority of which are native to Panama. The farmers had diverse reasons for maintaining trees, including improving the environment, providing food and shade for cattle, and generating a source of wood for construction, furniture, and firewood. Most of the trees mentioned in the study provide multiple uses and values and the majority of farmers wanted to plant additional trees. Some differences in species preferences and motivations for planting and protecting trees were seen between sites, thereby suggesting that land restoration and tree planting projects should be site specific. Our data indicate that there are ample opportunities to increase native tree cover in our study sites and highlight the need to incorporate farmer input into project design, implementation, and evaluation as a necessary and continuous feature throughout projects.

Toward an Era of Restoration in Ecology: Successes, Failures, and Opportunities Ahead

As an inevitable consequence of increased environmental degradation and anticipated future environmental change, societal demand for ecosystem restoration is rapidly increasing. Here, I evaluate successes and failures in restoration, how science is informing these efforts, and ways to better address decision-making and policy needs.

Toward Successful Reintroductions: The Combined Importance of Species Traits, Site Quality, and Restoration Technique

First, reintroduction success will be highest for endangered species that share traits with non- rare native species, invasive plants, and species that excel in restoration plantings as reviewed from the ecological literature. Ten traits are identified as common to at least two of these groups. Second, reintroductions will do best in habitats ecologically similar to existing wild populations and with few local threats, such as non-native plants and herbivores. And third, the methods used to establish plants, such as planting seeds vs. transplants or selecting appropriate microsites, will influence outcomes. For any reintroduction project, potential pitfalls associated with a particular species, site, or technique may be overcome by integrating information from all three areas. Conducting reintroductions as designed experiments that test clearly stated hypotheses will maximize the amount and quality of information gained from each project and support adaptive management.

Towards a Common Set of Criteria and Indicators to Identify Forest Restoration Priorities: An Expert Panel-based Approach

This investigation aimed to verify whether this might be achieved through the elicitation of experts’ opinion, when considering biodiversity conservation as the main objective of restoration. A Delphi process was performed, aimed at defining the key ecological criteria and a broad set of indicators. 389 criteria and 669 related indicators were provided in total and grouped into clusters relating to individual criteria. A total of 20 criteria referred to the need for restoration and 18 to its feasibility. In the second round of the Delphi process, 8 definitive criteria were identified along with some 90 related indicators. Finally, a face-to-face meeting was conducted to show how ready-to-use C&I can be obtained for application to a specific context starting from the Delphi’s results. The study highlights the potential value of combining the Delphi process and face-to-face meetings for identifying practically applicable C&I for planning ecological restoration. However, the diversity of views identified within a single group of stakeholders suggests that the development of a generally applicable set of C&I for forest restoration will be difficult to achieve in practice.

Trait Divergence and the Ecosystem Impacts of Invading Species

Plant functional traits are often used as proxies to determine whether species have different ecological strategies for reproduction and resource capture, and may provide mechanisms to explain which species are likely to invade, and which communities are likely to be invaded.

Tree Plantations on Farms: Evaluating Growth and Potential for Success

The manuscript describes survivorship and growth of four native tree species on farms over five years in the dry arc of Panama. The manuscript also provides five year growth data for 61 native tree species grown at two experimental or “species selection” trials at two sites adjacent to farm sites and discusses growth in relation to local farmer species preferences. Native species can grow well on rural farms but growth and survivorship depend upon both local site conditions and farmer management. Rural farmers will stay engaged with tree planting projects over long periods of time as long as expectations are managed and extension services are provided.

Trophic Downgrading of Planet Earth

Until recently, large apex consumers were ubiquitous across the globe and had been for millions of years. The loss of these animals may be humankind’s most pervasive influence on nature. Although such losses are widely viewed as an ethical and aesthetic problem, recent research reveals extensive cascading effects of their disappearance in marine, terrestrial, and freshwater ecosystems worldwide. This empirical work supports long-standing theory about the role of top-down forcing in ecosystems but also highlights the unanticipated impacts of trophic cascades on processes as diverse as the dynamics of disease, wildfire, carbon sequestration, invasive species, and biogeochemical cycles. These findings emphasize the urgent need for interdisciplinary research to forecast the effects of trophic downgrading on process, function, and resilience in global ecosystems.