Forest Restoration in a Mixed-Ownership Landscape under Climate Change

The article presents a study regarding forest management associated with climate change. It mentions that preservation endeavors and restoration schemes should diminish current threats like unsuited forest management and development while integrating possible effects of climate change. It also stresses that an adaptive approach to management can be the most efficient strategy of forest restoration given the doubts of climate change impacts

Historical framework to explain long-term coupled human and natural system feedbacks: application to a multiple-ownership forest landscape in the northern Great Lakes region, USA

Current and future human and forest landscape conditions are influenced by the cumulative, unfolding history of social-ecological interactions. Examining past system responses, especially unintended consequences, can reveal valuable insights that promote learning and adaptation in forest policy and management. Temporal couplings are complex, however; they can be difficult to trace, characterize, and explain. We develop a framework that integrates environmental history into analysis of coupled human and natural systems (CHANS). Our study demonstrates how historical data and methods can help to explain temporal complexity of long-term CHANS feedbacks. We focus on two sources of temporal complexity: legacy effects and lagged interactions. We apply our framework to a multiple-ownership forest landscape comprising tribal and nonindustrial private forest ownerships in Wisconsin. Our framework features four elements that help investigators better understand complex systems through time: (1) a temporal axis parsed into historical periods (periodization), (2) representation of links between historical periods and system feedbacks, (3) representation of land ownership history, and (4) nested geographical scales of historical analysis. The framework can help to reveal legacy effects and lagged interactions, illuminate turning points and periods in system dynamics, and distil insights from unintended consequences that inform institutional and policy adaptation. We also assess the validity of using land ownership to represent the social component of CHANS models. When treated as a categorical variable and interpreted in historical context, land ownership can validly represent decision-making structure, culture, and knowledge system in spatially explicit social-ecological models

Ownership and ecosystem as sources of spatial heterogeneity in a forested landscape, Wisconsin, USA

The interaction between physical environment and land ownership in creating spatial heterogeneity was studied in largely forested landscapes of northern Wisconsin, USA. A stratified random approach was used in which 2500-ha plots representing two ownerships (National Forest and private non-industrial) were located within two regional ecosystems (extremely well-drained outwash sands and moderately well-drained moraines). Sixteen plots were established, four within each combination of ownership and ecosystem, and the land cover on the plots was classified from aerial photographs using a modified form of the Anderson (U.S. Geological Survey) land use and land cover classification system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43156/1/10980_2004_Article_206157.pd

Tree regeneration and spatial patterning among midtolerant tree species following gap-based harvesting in a temperate hardwood forest

IntroductionField experiments of gap-based harvest systems in temperate northern hardwood forests have provided inconsistent support for the theory that such regeneration approaches can improve regeneration success among increasingly underrepresented tree species intermediate in shade tolerance. We established a field experiment in Wisconsin, USA testing the long-term response of tree regeneration to group selection harvesting that created small (50 m2–D:H 0.32), medium (200 m2—D:H 0.64) and large (380 m2—D:H 0.88) gaps.Materials and methodsLight levels were modeled to test the assumption of resource heterogeneity within and across these gap sizes. Spatial statistics were used to assess whether the point patterns of saplings of several midtolerant tree species (Betula alleghaniensis, Carya cordiformis, Fraxinus spp.) mapped in harvest gaps provided evidence for partitioning across resource gradients 9 years post-harvest. Finally, we measured occurrence and height of all saplings within the harvest gaps to test the effects of gap size and deer exclusion fencing on the density and total height of shade-tolerant and midtolerant tree regeneration.Results and discussionLight levels progressively increased with gap size, varied by position within gaps, and provided significant evidence of resource heterogeneity. The complex light gradients formed both within and across the three gap sizes may partially explain the statistically significant clustering of Fraxinus spp. saplings in gap centers and north and east into the forested edge of medium and large gaps, C. cordiformis on the west sides of forested transitions surrounding large gaps, and B. alleghaniensis in the centers of large gaps. Densities of tolerant and midtolerant saplings were similar in medium and large gaps after nine growing seasons, though tolerant saplings averaged two meters taller across all three gap sizes. Our results show that gap-based silvicultural systems can create resource gradients that are sufficient to regenerate mixtures of species with high to intermediate tolerance of shade. However, prescriptions beyond harvesting and deer exclusion fencing may be necessary for the recruitment of midtolerant species to canopy positions

Statistically-Estimated Tree Composition for the Northeastern United States at Euro-American Settlement

We present a gridded 8 km-resolution data product of the estimated composition of tree taxa at the time of Euro-American settlement of the northeastern United States and the statistical methodology used to produce the product from trees recorded by land surveyors. Composition is defined as the proportion of stems larger than approximately 20 cm diameter at breast height for 22 tree taxa, generally at the genus level. The data come from settlement-era public survey records that are transcribed and then aggregated spatially, giving count data. The domain is divided into two regions, eastern (Maine to Ohio) and midwestern (Indiana to Minnesota). Public Land Survey point data in the midwestern region (ca. 0.8-km resolution) are aggregated to a regular 8 km grid, while data in the eastern region, from Town Proprietor Surveys, are aggregated at the township level in irregularly-shaped local administrative units. The product is based on a Bayesian statistical model fit to the count data that estimates composition on the 8 km grid across the entire domain. The statistical model is designed to handle data from both the regular grid and the irregularly-shaped townships and allows us to estimate composition at locations with no data and to smooth over noise caused by limited counts in locations with data. Critically, the model also allows us to quantify uncertainty in our composition estimates, making the product suitable for applications employing data assimilation. We expect this data product to be useful for understanding the state of vegetation in the northeastern United States prior to large-scale Euro-American settlement. In addition to specific regional questions, the data product can also serve as a baseline against which to investigate how forests and ecosystems change after intensive settlement. The data product is being made available at the NIS data portal as version 1.0

Understory Species Patterns and Diversity in Old-Growth and Managed Northern Hardwood Forests

Forest management can significantly affect both the diversity and spatial patterning of understory vegetation. However, few studies have considered both diversity and spatial patterning at a stand scale. Our objective was to evaluate the effects of forest management on understory plant communities in northern hardwood forests and assess the processes governing differences in species composition, diversity, and spatial patterns. We sampled understory vegetation (all speciestall) and percentage of light transmission levels in three forest types in 12 mesic northern hardwood stands in northern Wisconsin and the Upper Peninsula of Michigan, USA: old-growth, undisturbed forests; even-aged forests resulting from clearcut logging (65–85 yr old); and uneven-aged forests with recent selective logging. Estimated understory species richness per stand, mean species richness per quadrat, and mean percent cover per quadrat were lower in old-growth forest than in even-aged, second-growth forests and lower in even-aged than in uneven-aged, second-growth forests. Differences in species composition among the three forest types were related to available light and to coarse woody debris; however, differences between the cover of most plant groups were not significant. The mean patch size of species diversity and cover is highly variable and could not be related to forest stand type. However, understory communities in old-growth forests have significantly smaller community patch sizes and larger compositional heterogeneity. Community patch size is correlated with both coarse woody debris and light heterogeneity. Each forest stand type produces a characteristic combination of understory composition, diversity, and spatial patterning of communities. Although harvesting has negligible effects on understory alpha diversity in these mesic hardwood forests, spatial structure is slower to recover and has not recovered in the even- and uneven-aged northern hardwood forests studied. If management objectives include preserving or restoring the ecological character of the forest, harvesting may need to be altered or delayed predicated on the character of the understory