Randy Swaty

Simulating the cumulative effects of multiple forest management strategies on landscape measures of forest sustainability

While the cumulative effects of the actions of multiple owners have long been recognized as critically relevant to efforts to maintain sustainable forests at the landscape scale, few studies have addressed these effects. We used the HARVEST timber harvest simulator to predict the cumulative effects of four owner groups (two paper companies, a state forest and non-industrial private owners) with different management objectives on landscape pattern in an upper Michigan landscape managed primarily for timber production. We quantified trends in landscape pattern metrics that were linked to Montreal Process indicators of forest sustainability, and used a simple wildlife habitat model to project habitat trends. Our results showed that most trends were considered favorable for forest sustainability, but that some were not. The proportion of all age classes and some forest types moved closer to presettlement conditions. The trend for the size of uneven-aged patches was essentially flat while the average size of patches of the oldest and youngest age classes increased and the size of patches of the remaining age classes decreased. Forest fragmentation generally declined, but edge density of age classes increased. Late seral forest habitat increased while early successional habitat declined. The owners use different management systems that cumulatively produce a diversity of habitats. Our approach provides a tool to evaluate such cumulative effects on other landscapes owned by multiple owners. The approach holds promise for helping landowner groups develop and evaluate cooperative strategies to improve landscape patterns for forest sustainability.

Accounting for Ecosystem Alteration Doubles Estimates of Conservation Risk in the Conterminous United States

Previous national and global conservation assessments have relied on habitat conversion data to quantify conservation risk. However, in addition to habitat conversion to crop production or urban uses, ecosystem alteration (e.g., from logging, conversion to plantations, biological invasion, or fire suppression) is a large source of conservation risk. We add data quantifying ecosystem alteration on unconverted lands to arrive at a more accurate depiction of conservation risk for the conterminous United States. We quantify ecosystem alteration using a recent national assessment based on remote sensing of current vegetation compared with modeled reference natural vegetation conditions. Highly altered (but not converted) ecosystems comprise 23% of the conterminous United States, such that the number of critically endangered ecoregions in the United States is 156% higher than when calculated using habitat conversion data alone. Increased attention to natural resource management will be essential to address widespread ecosystem alteration and reduce conservation risk.

Collaborative scenario modeling reveals potential advantages of blending strategies to achieve conservation goals in a working forest landscape

ContextBroad-scale land conservation and management often involve applying multiple strategies in a single landscape. However, the potential outcomes of such arrangements remain difficult to evaluate given the interactions of ecosystem dynamics, resource extraction, and natural disturbances. The costs and potential risks of implementing these strategies make robust evaluation critical.ObjectivesWe used collaborative scenario modeling to compare the potential outcomes of alternative management strategies in the Two Hearted River watershed in Michigan’s Upper Peninsula to answer key questions: Which management strategies best achieve conservation goals of maintaining landscape spatial heterogeneity and conserving mature forests and wetlands? And how does an increase in wildfire and windthrow disturbances influence these outcomes?MethodsScenarios were modeled using the VDDT/TELSA state-and-transition modeling suite, and resulting land cover maps were analyzed using ArcGIS, FRAGSTATS, and R statistical software.ResultsResults indicate that blending conservation strategies, such as single-ownership forest reserves and working forest conservation easements in targeted areas of the landscape, may better achieve these goals than applying a single strategy across the same area. However, strategies that best achieve these conservation goals may increase the sensitivity of the landscape to changes in wildfire and windthrow disturbance regimes.ConclusionsThese results inform decision-making about which conservation strategy or combination of strategies to apply in specific locations on the landscape to achieve optimum conservation outcomes, how to best utilize scarce financial resources, and how to reduce the financial and ecological risks associated with the application of innovative strategies in an uncertain future.

The Next Frontier: Projecting the Effectiveness of Broad-scale Forest Conservation Strategies

Conservation and land management organizations such as The Nature Conservancy are developing conservation strategies to distribute protection efforts over larger areas and a broader range of ownership and management techniques. These “distributed conservation strategies,” such as working forest conservation easements, are based on the premise that blending resource extraction, such sustainable timber harvest, and conservation should yield greater socio-economic benefits without significantly compromising the conservation of biodiversity or the sustainable provisioning of ecosystem services. However, it is unknown how well these strategies will compare to traditional conservation preserves or if they will be robust to climate change and resource demand over the coming centuries. Due to scarce financial resources and the relative difficulty of negotiating easement acquisitions, it is important for forest conservation and management organizations to know which strategies most effectively meet conservation goals. Meanwhile, the long duration required to evaluate most monitoring questions leads to a lag in knowledge transfer and delayed adaptive management. In this chapter, we discuss the challenges and constraints to measuring conservation effectiveness and illustrate a scenario-building approach that we are applying to understand and compare the conservation effectiveness of various conservation strategies in two large conservation acquisitions in the Great Lakes region of the United States. We show how this approach can be used to evaluate potential outcomes for biodiversity and the provision of ecosystem services resulting from varying conservation strategies and discuss implications of this approach for the future of forest conservation.

Mycorrhizas, Drought, and Host-Plant Mortality

Abstract As the Earths climate changes, droughts are expected to become more intense, with consequences for plants and mycorrhizal fungi. We review recent studies examining the effects of drought on mycorrhizal fungi and the influence of mycorrhizal fungi on host plant–water relationships and drought tolerance. We also examine the consequences of drought-induced host mortality to mycorrhizal fungi and ecosystem processes using examples from the western United States. Mycorrhizal fungal abundance in roots and soil, as well as mycorrhizal fungal species composition, diversity, and activity are often affected by drought. Likewise both arbuscular (AM) and ectomycorrhizal (EcM) fungi increase the drought tolerance of their host plants, with more pronounced beneficial effects as drought stress increases. Host-plant mortality related to drought appears to disproportionately affect EcM plant species, with potential consequences for EcM fungi, the regeneration of plant hosts and ecosystem properties such as carbon (C) sequestration and nutrient cycling.