Rebecca Benner’s essay on resilience asks how we should identify this complex ecosystem property and whether we should protect it where it is strong or enhance it where it is weak. Let us first lay a quick foundation of understanding for dealing with these questions.
As homeostatic macro-organisms, communities over time maintain some level of constancy of measurable diagnostic features (species composition, abundance distribution, energy and material flows). This self-regulation is due to network interactions which lead to emergent system properties. It is not inherent to any of the elements of the system by itself.
Ecological resilience — the ability of such systems to bounce back to certain conditions after having been pushed away from them (“basins of attraction”) — can only be inferred from proxies such as community structure or geological heterogeneity. Anderson et al. (2012) perform such analyses at a regional scale; however, as they state, they are estimating the capacity to adapt rather than resilience. Measuring resilience directly would require either destroying the system or “playing out the movie,” i.e., sitting and waiting for things to happen (Lewin 1992, Gell-Mann 1994).
It is also important to distinguish resilience (bouncing back to the same previous condition, e.g., Holling 1986, Naeem & Li 1997, Berkes et al. 2000) from adaptation (being able to change to track a changing landscape, e.g., IPCC 2007, Groves 2012), as both may in fact be to some degree contradictory (Kauffman 1991, 1993; Whitacre & Bender 2009).
Given external drivers such as drought, fire, pests, deforestation and urban development, system features will change. Given time, the system will either come back to some or all the original features or not, depending on the duration and intensity of the driver (Halloy & Barratt 2007). We know some of the return mechanisms, like succession. But for most practical systems, we don’t know the response curve and thresholds — i.e., the point at which the system will shift from one state (or basin of attraction) to another…from a clear-water lake to a eutrophized turbid lake, for example.
A framework that addresses parts of the dilemmas suggested by Rebecca distinguishes four types of areas in the face of drivers such as climate change:
1. “No change” (or minor change) areas. These are the areas identified by Anderson et al. (2012) or Killeen et al.’s refugia (Killeen et al. 2007, Weiser et al. 2007, Killeen & Solórzano 2008). They are in some ways the analogue of Peter Kareiva and Michelle Marvier’s “coldspots” in that they are less threatened yet need attention nonetheless. These are the obvious “protect as they are” choices.
2. “Total change” areas, where future climates will have no current equivalent (Williams et al. 2007, Jarvis et al. 2008). These are the most threatened areas and will require high investment in rebuilding new functional ecosystems (for whatever purpose society decides).
3. “Equivalent areas” but in different places — i.e., areas with comparable geology, soils and climates in the future. In other words, site B, which today has a different climate and biota from site A, will in 2050 be an equivalent area to site A and could support species from site A. These areas require a combination of appropriate connectivity and possibly assisted migration and rebuilding.
4. “Corridors,” i.e., areas which allow the percolation of species from site A to B as conditions change. These areas require careful management across typically productive landscapes to facilitate species migrating through them.
A conservation portfolio with a whole-system view (Ward et al. 2011) should probably consider a balance of all these types of areas and intermediate variations.
It is worth taking into account the two extremes of “why we care”: the “grandma’s teapot” (museum) vs the “plastic jug” (machine) consideration. We make efforts to conserve pandas or quetzals mainly based on grandma’s teapot considerations, regardless of function. We conserve watersheds to conserve function (i.e., the supply and quality of water) regardless of which species and communities ensure that function. We cannot choose to do only one or the other. Human nature and necessities means we will, somehow or other, always do both. Our challenge as scientists is to provide the information to balance society’s choices. We should have museums, but we can’t cover our cities only in museums. We need industry and housing, but our societies would not accept having only productive uses.
Andean societies have long learned such balanced approaches. They learnt from past trial and error (playing the movie, but in the past) to develop sophisticated cultural and social institutions that use and manage connectivity and whole systems (verticality and reciprocity) rather than manage compartments (Halloy et al. 2005, Orlove 2005, Perez et al. 2010).
Large-scale, whole-system approaches such as those initiated by TNC`s Southern Andes conservation program in large watersheds (Lima, Peru; La Paz, Bolivia; Aconcagua and Maipo, Chile) provide opportunities to work with biodiversity, ecosystem function, social, cultural and economic interactions with a consideration of traditional knowledge. Such approaches cultivate the emergent properties of eco-social systems to allow them to bounce back (resilience) after disruptions as well as to adapt to change (Halloy et al. 2010).
Traditional conservation approaches have varied between intense command and control (Holling & Meffe 1996) and laissez-faire (Thoreau 1854, Walker & Salt 2007). Without entering into the philosophical debate, it is well to understand the consequences of adopting one or the other strategy and the degrees in between. Aquariologists understand that it takes effort to construct a balanced microcosm of water, fish, snails, microflora, vascular plants, and external inputs of light, water circulation, etc. But once a certain threshold is reached, the system “pops” — i.e., it stabilizes in a desired condition which requires a minimum of sustained inputs (Kelly 1994, Lehrer 2012). Maybe there are important lessons here!
Rebecca Benner’s questions are dilemmas for most land stewards, many from before climate change was on the horizon: using standard consensus approaches, definitions, methods and measures are constant challenges which have a lot to do with human culture and fragmentation of science.
Berkes, F., J. Colding, & C. Folke. 2000. Rediscovery of traditional ecological knowledge as adaptive management. Ecological Applications 10:1251–1262.
Gell-Mann, M. 1994. The Quark and the Jaguar. Adventures in the Simple and the Complex. W.H.Freeman and Co., New York.
Groves, C. 2012. Mapping impacts, threats and strategies for adaptation: The Yale Mapping Framework. Science Chronicles August 2012:21-22.
Halloy, S. R. P. & B. I. P. Barratt. 2007. Patterns of abundance and morphology as indicators of ecosystem status: a meta-analysis. Ecological Complexity 4:128-147.
Halloy, S. R. P., R. Ortega Dueñas, K. Yager, & A. Seimon. 2005. Traditional Andean cultivation systems and implications for sustainable land use. Acta Horticulturae 670:31-55.
Halloy, S. R. P., K. Yager, S. Beck, & C. García. 2010. El cambio del clima en el contexto de cambios en la biosfera y la noosfera - ¿cuáles son los riesgos y qué podemos hacer? Pages 602-612 in S. G. Beck, N. Paniagua-Zambrana, R. P. López, and N. Nagashiro, editors. Biodiversidad y Ecología en Bolivia, Memorias del Simposio del XXX Aniversario del Instituto de Ecología. Instituto de Ecología, Universidad Mayor de San Andrés (UMSA), La Paz.
Holling, C. S. 1986. Resilience of ecosystems; local surprise and global change. Pages 292-317 in W. C. Clark and R. E. Munn, editors. Sustainable development of the biosphere. Cambridge University Press, Cambridge, UK.
Holling, C. S. & G. K. Meffe. 1996. Command and control and the pathology of natural resource management. Conservation Biology 10:328-337.
IPCC. 2007. Working Group II Contribution to the Intergovernmental Panel on Climate Change Fourth Assessment Report. Climate Change 2007: Climate Change Impacts, Adaptation and Vulnerability - Summary for Policymakers. 6 April 2007 edition.
Jarvis, A., A. Lane, & R. J. Hijmans. 2008. The effect of climate change on crop wild relatives. Agriculture, Ecosystems and Environment 126(1-2):13-23.
Kauffman, S. A. 1991. Antichaos and adaptation. Scientific American 265:64-70.
Kauffman, S. A. 1993. The Origins of Order. Oxford University Press, New York.
Kelly, K. 1994. Out of Control--The new biology of machines, social systems, and the economic world. Addison-Wesley, Reading, Mass.
Killeen, T. & L. A. Solórzano. 2008. Conservation strategies to mitigate impacts from climate change in Amazonia. Philosophical Transactions of the Royal Society B 363:1881-1888.
Killeen, T. J., M. Douglas, T. Consiglio, P. M. Jørgensen, & J. Mejia. 2007. Dry spots and wet spots in the Andean hotspot. Journal of Biogeography Special issue:1-17.
Lewin, R. 1992. Complexity--Life at the edge of chaos. Macmillan Publishing, New York.
Naeem, S. & S. Li. 1997. Biodiversity enhances ecosystem reliability. Nature 390:507-509.
Orlove, B. 2005. Human adaptation to climate change: a review of three historical cases and some general perspectives. Environmental Science & Policy 8:589-600.
Perez, C., C. Nicklin, O. Dangles, S. Vanek, S. Sherwood, S. Halloy, K. Garrett, & G. Forbes. 2010. Climate change in the High Andes: Implications and adaptation strategies for small-scale farmers. International Journal of Environmental, Cultural, Economic & Social Sustainability 6:1-16.
Thoreau, H. D. 1854. Walden; or, life in the woods. 1995 unabridged edition of the 1854 Ticknor and Fields publication in Boston edition. Dover Publication Inc., New York.
Walker, B. & D. Salt. 2007. Resilience Thinking — Sustaining Ecosystems and People in a Changing World. Island Press.
Ward, J., V. Agostini, M. Anderson, C. Burns, P. Doran, J. Fargione, C. Groves, L. Hanners, J. Hoekstra, R. Marshall, S. Morrison, S. Palmer, D. Shaw, & J. Smith. 2011. Stepping up to the challenge: A concept paper on whole system conservation. The Nature Conservancy (TNC).
Weiser, M. D., B. J. Enquist, B. Boyle, T. J. Killeen, P. M. Jørgensen, G. A. B. d. Fonseca, M. D. Jennings, A. J. Kerkhoff, T. E. L. Jr., A. Monteagudo, M. P. N. Vargas, O. L. Phillips, N. G. Swenson, & R. V. Martínez. 2007. Latitudinal patterns of range size and species richness of New World woody plants. Global Ecology and Biogeography 16:679-688.
Whitacre, J. & A. Bender. 2009. Degeneracy: a design principle for achieving robustness and evolvability. arXiv:0907.0510.
Williams, J. W., S. T. Jackson, & J. E. Kutzbach. 2007. Projected distributions of novel and disappearing climates by 2100 AD. Proceedings of the National Academy of Sciences of the United States of America. Early edition:1-5.
Stephan Halloy is the science coordinator of the Southern Andes Conservation Program of The Nature Conservancy.