Climate Change and Forests of the Future: Managing in the Face of Uncertainty

We offer a conceptual framework for managing forested ecosystems under an assumption that future environments will be different from present but that we cannot be certain about the specifics of change. We encourage flexible approaches that promote reversible and incremental steps, and that favor ongoing learning and capacity to modify direction as situations change. We suggest that no single solution fits all future challenges, especially in the context of changing climates, and that the best strategy is to mix different approaches for different situations. Resources managers will be challenged to integrate adaptation strategies (actions that help ecosystems accommodate changes adaptively) and mitigation strategies (actions that enable ecosystems to reduce anthropogenic influences on global climate) into overall plans. Adaptive strategies include resistance options (forestall impacts and protect highly valued resources), resilience options (improve the capacity of ecosystems to return to desired conditions after disturbance), and response options (facilitate transition of ecosystems from current to new conditions). Mitigation strategies include options to sequester carbon and reduce overall greenhouse gas emissions. Priority-setting approaches (e.g., triage), appropriate for rapidly changing conditions and for situations where needs are greater than available capacity to respond, will become increasingly important in the future.

Conserving biodiversity under climate change: the rear edge matters

We review recent findings from the fossil record, phylogeography and ecology to illustrate that rear edge populations are often disproportionately important for the survival and evolution of biota. Their ecological features, dynamics and conservation requirements differ from those of populations in other parts of the range, and some commonly recommended conservation practices might therefore be of little use or even counterproductive for rear edge populations.

Adapting landscapes to climate change: examples of climate-proof ecosystem networks and priority adaptation zones

1. Climate change has been inducing range shifts for many species as they follow their suitable
climate space and further shifts are projected. Whether species will be able to colonize regions where
climate conditions become suitable, so-called ‘new climate space’, depends on species traits and
habitat fragmentation.
2. By combining bioclimate envelope models with dispersal models, we identified areas where the
spatial cohesion of the ecosystem pattern is expected to be insufficient to allow colonization of new
climate space.
3. For each of three ecosystem types, three species were selected that showed a shift in suitable
climate space and differed in habitat fragmentation sensitivity.
4. For the 2020 and 2050 time slices, the amount of climatically suitable habitat in northwest
Europe diminished for all studied species. Additionally, significant portions of new suitable habitat
could not be colonized because of isolation. Together, this will result in a decline in the amount of
suitable habitat protected in Natura 2000 sites.
5. We develop several adaptation strategies to combat this problem: (i) link isolated habitat that is
within a new suitable climate zone to the nearest climate-proof network; (ii) increase colonizing
capacity in the overlap zone, the part of a network that remains suitable in successive time frames;
(iii) optimize sustainable networks in climate refugia, the part of a species’ range where the climate
remains stable.
6. Synthesis and applications. Following the method described in this study, we can identify those
sites across Europe where ecosystem patterns are not cohesive enough to accommodate species’
responses to climate change. The best locations for climate corridors where improving connectivity
is most urgent and potential gain is highest can then be pinpointed.

The Butterfly Effect: Conservation Easements, Climate Change, and Invasive Species

This Article explains that one of the consequences of climate change will be migrations of species from their native habitats to newer habitats, typically to the north, with climates similar to those in which such species evolved. These in-migrating species will in many cases be invasive, forcing the native species to out-migrate or be driven to extinction, thereby causing biodiversity loss. As many of these disrupted ecosystems may be protected by perpetual conservation easements, the Article discusses the negative legal consequences of incursions by non-native species on these existing conservation easements. Accordingly, the Article suggests a number of changes that can be made to future conservation easements to help insure their protection of land in perpetuity and to better protect species and their habitats from the effects of climate change-caused migrations.

Building evolutionary resilience for conserving biodiversity under climate change

Evolution occurs rapidly and is an ongoing process in our environments. Evolutionary principles need to be built into conservation efforts, particularly given the stressful conditions organisms are increasingly likely to experience because of climate change and ongoing habitat fragmentation. The concept of evolutionary resilience is a way of emphasizing evolutionary processes in conservation and landscape planning. From an evolutionary perspective, landscapes need to allow in situ selection and capture high levels of genetic variation essential for responding to the direct and indirect effects of climate change. We summarize ideas that need to be considered in planning for evolutionary resilience and suggest how they might be incorporated into policy and management to ensure that resilience is maintained in the face of environmental degradation.

Beyond Kyoto: Forest Management in a Time of Rapid Climate Change

Policies to reduce global warming by offering credits for carbon sequestration have neglected the effects of forest management on biodiversity. I review properties of forest ecosystems and management options for enhancing the resistance and resilience of forests to climate change. Although forests, as a class, have proved resilient to past changes in climate, today’s fragmented and degraded forests are more vulnerable. Adaptation of species to climate change can occur through phenotypic plasticity, evolution, or migration to suitable sites, with the latter probably the most common response in the past.

Assessing species vulnerability to climate change

The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species’ vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, we summarize different currencies used for assessing species’ climate change vulnerability. We describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. Read More >