What is resilience?

Among many definition of resilience, the International Panel on Climate Change (IPCC) proposes the following: "the ability of a system and its component parts to anticipate, absorb, accommodate, or recover from the effects of a potentially hazardous event in a timely and efficient manner, including through ensuring the preservation, restoration, or improvement of its essential basic structures and functions" (Climate Change: New Dimensions in Disaster Risk, Exposure, Vulnerability, and Resilience).

Ecological resilience

Resilience.jpg

Source: Reproduced from Keane, R. E., R. A. Loehman, L. M. Holsinger, D. A. Falk, P. Higuera, S. M. Hood, and P. F. Hessburg. 2018. Use of landscape simulation modeling to quantify resilience for ecological applications. Ecosphere 9(9):e02414. 10.1002/ecs2. 2414

The ball and cup represent the ecosystem and the ecosystem's different possible states, respectively.

The resilience of the ecosystem is expressed by the difficulty of moving the ball from one cup to the next: the harder the moving is, the more resilient the system is.

Planetary boundaries and tipping points

As a response to the climate change, increased tree mortality and biodiversity loss, the European Green Deal, the EU Biodiversity Strategy for 2030, and the new EU Forest Strategy for 2030 call to increase forests' resilience to natural disturbances.

Climate change, biodiversity loss and land-use changes are parts of the planetary boundaries (Science.org).

Resilience is influenced by planetary boundaries and tipping points

Source: Reproduced from Rockström, J., W. Steffen, K. Noone, Å. Persson, F. S. Chapin, III, E. Lambin, T. M. Lenton, M. Scheffer, C. Folke, H. Schellnhuber, B. Nykvist, C. A. De Wit, T. Hughes, S. van der Leeuw, H. Rodhe, S. Sörlin, P. K. Snyder, R. Costanza, U. Svedin, M. Falkenmark, L. Karlberg, R. W. Corell, V. J. Fabry, J. Hansen, B. Walker, D. Liverman, K. Richardson, P. Crutzen, and J. Foley. 2009. Planetary boundaries:exploring the safe operating space for humanity. Ecology and Society 14(2):3

Tipping points and connectivity

Source: Reproduced from Climate tipping points — too risky to bet against (T. M. Lenton et al.2019)

Tipping points mark the abrupt shift between contrasting ecosystem states (broadly termed regime shifts) when environmental conditions cross specific thresholds. Even a small perturbation can cause a fundamental and often irreversible change in the ecosystem (Environmental Tipping Points).

For example, a drought period leading into a widespread tree mortality and lack of regeneration potential might turn a forest into a shrubland.

Source: Vasilis Dakos, Blake Matthews, Andrew Hendry, Jonathan Levine, Nicolas Loeuille, et al.. Ecosystemtipping points in an evolving world. Nature Ecology & Evolution, Nature, 2019, 3 (3), pp.355-362. 10.1038/s41559-019-0797-2 . hal-02194979

Forest resilience

Forest resilience has several vital components, e.g., biodiversity, adaptive capacity and connectivity. These components play an essential role in making forests more resilient to disturbances.

Applied to the forestry sector, resilience thinking implies using diverse forest management practices and forest governance that encourages diversity rather than ‘one solution fits all. Such adaptive management strategies favour open options and coping with uncertainty.

Aspects of forest resilience

Aspects of resilience.jpg

Source:
Reproduced from Keane, R. E., R. A. Loehman, L. M. Holsinger, D. A. Falk, P. Higuera, S. M. Hood, and P. F. Hessburg. 2018. Use of landscape simulation modeling to quantify resilience for ecological applications. Ecosphere 9(9):e02414. 10.1002/ecs2. 2414