Matthew J. Duveneck

Methods for translating narrative scenarios into quantitative assessments of land use change

In the land use and land cover (LULC) literature, narrative scenarios are qualitative descriptions of plausible futures associated with a combination of socio-economic, policy, technological, and climate changes. LULC models are then often used to translate these narrative descriptions into quantitative characterizations of possible future societal and ecological impacts and conditions. To respect the intent of the underlying scenario descriptions, this process of translation needs to be thoughtful, transparent, and reproducible. This paper evaluates the current state of the art in scenario translation methods and outlines their relative advantages and disadvantages, as well as the respective roles of stakeholders and subject matter experts. We summarize our findings in the form of a decision matrix that can assist land use planners, scientists, and modelers in choosing a translation method appropriate to their situation. Assessments of land use and land cover change often employ narrative scenarios.Detailed evaluation of policy actions and outcomes requires quantitative model output.We review methods of translating narrative scenarios into model-based assessments.A summary table provides guidance for choosing a method suitable for the situation.

What is Novel About Novel Ecosystems: Managing Change in an Ever-Changing World.

AbstractInfluenced by natural climatic, geological, and evolutionary changes, landscapes and the ecosystems within are continuously changing. In addition to these natural pressures, anthropogenic drivers have increasingly influenced ecosystems. Whether affected by natural or anthropogenic processes, ecosystems, ecological communities, and ecosystem functioning are dynamic and can lead to “novel” or “emerging” ecosystems. Current literature identifies several definitions of these ecosystems but lacks an unambiguous definition and framework for categorizing what constitutes a novel ecosystem and for informing decisions around best management practices. Here we explore the various definitions used for novel ecosystems, present an unambiguous definition, and propose a framework for identifying the most appropriate management option. We identify and discuss three approaches for managing novel ecosystems: managing against, tolerating, and managing for these systems, and we provide real-world examples of each approach. We suggest that this framework will allow managers to make thoughtful decisions about which strategy is most appropriate for each unique situation, to determine whether the strategy is working, and to facilitate decision-making when it is time to modify the management approach.

Michigan forest ecosystem vulnerability assessment and synthesis: a report from the Northwoods Climate Change Response Framework project

Forests in northern Michigan will be affected directly and indirectly by a changing climate during the next 100 years. This assessment evaluates the vulnerability of forest ecosystems in Michigans eastern Upper Peninsula and northern Lower Peninsula to a range of future climates. Information on current forest conditions, observed climate trends, projected climate changes, and impacts to forest ecosystems was considered in order to draw conclusions on climate change vulnerability. Upland spruce-fir forests were determined to be the most vulnerable, whereas oak associations and barrens were determined to be less vulnerable to projected changes in climate. Projected changes in climate and the associated ecosystem impacts and vulnerabilities will have important implications for economically valuable timber species, forest-dependent wildlife and plants, recreation, and long-range planning.

Measuring and managing resistance and resilience under climate change in northern Great Lake forests (USA)

ContextClimate change will have diverse and interacting effects on forests over the next century. One of the most pronounced effects may be a decline in resistance to chronic change and resilience to acute disturbances. The capacity for forests to persist and/or adapt to climate change remains largely unknown, in part because there is not broad agreement how to measure and apply resilience concepts.ObjectivesWe assessed the interactions of climate change, resistance, resilience, diversity, and alternative management of northern Great Lake forests.MethodsWe simulated two landscapes (northern Minnesota and northern lower Michigan), three climate futures (current climate, a low emissions trajectory, and a high emissions trajectory), and four management regimes [business as usual, expanded forest reserves, modified silviculture, and climate suitable planting (CSP)]. We simulated each scenario with a forest landscape simulation model. We assessed resistance as the change in species composition over time. We assessed resilience and calculated an index of resilience that incorporated both recovery of pre-fire tree species composition and aboveground biomass within simulated burned areas.ResultsResults indicate a positive relationship between diversity and resistance within low diversity areas. Simulations of the high emission climate future resulted in a decline in both resistance and resilience.ConclusionsOf the management regimes, the CSP regime resulted in some of the greatest resilience under climate change although our results suggest that differences in forest management are largely outweighed by the effects of climate change. Our results provide a framework for assessing resistance and resilience relevant and valuable to a broad array of ecological systems.

Climate change imposes phenological trade‐offs on forest net primary productivity

Climate warming is expected to lengthen growing seasons of temperate forest ecosystems and increase gross primary productivity. Simultaneously, warming is expected to increase summer ecosystem respiration, which could offset gains accrued from longer growing seasons. These responses have been observed during anomalously warm years, but the role of future climate change on phenological tradeoffs and how they affect net primary productivity (NPP) at regional scales in temperate forests remains unexplored. We simulated scenarios of climate change on monthly forest NPP throughout 18 million hectares of temperate forests in New England, USA through year 2100. Using an ecophysiological model coupled to a forest landscape model, we simulated scenarios of climate change on monthly NPP. A high emission scenario (RCP 8.5), resulted in longer growing seasons that offset mid-summer ecosystem respiration costs and produced greater annual NPP throughout the study landscape compared to simulations using the current climate. In spring and autumn months, temperature was positively associated with greater NPP; in summer months, the relationship was negative. Spatially, the greatest increase in NPP occurred in the warmer southern region under a warm climate scenario with increased precipitation. Under a warm scenario with drier conditions, the greatest increase in NPP occurred in the cooler northern region. Phenological tradeoffs will affect NPP of future forests and their potential to serve as a negative feedback to climate change. Barring other limitations, longer growing seasons will offset greater respiratory demands and contribute to increases in NPP throughout the temperate forests of New England in the future.