How to resist global change in the Mediterranean region?

03/02/2015

The multidisciplinary team, formed by 28 researchers, has evaluated the progress made in the past 16 years on the study on climate change in terrestrial ecosystems of the Mediterranean and has concluded that science is faced with thirteen important challenges it must overcome and three fundamental aspects to take into account.

The article was published in the journal Global Ecology and Biogeography. UAB researchers who participated in the project were Jordi Martínez-Vilalta, Francesc Lloret, Xavier Pons and Javier Retana.

Firstly, they affirm that it is not enough to study the different modifications produced to the ecosystems (climate change, changes in fire regimes, loss of biodiversity, etc.) as if they were closed boxes. Efforts must be put into "understanding how each one of these boxes interacts with the others", affirms Enrique Doblas, researcher at CREAF. And he poses one example: "Droughts can cause soil erosion, but the erosion we are finding cannot be explained if we do not take into account all other changes in the soil in the past 50 or 60 years."

Secondly, the data gathered at small scale usually generates too many errors when used to predict the effects of global change at large scale. To reverse this situation, the authors of the article propose improving data exchange networks among researchers and designing long-term experiments at regional, or even global level.

Thirdly, they insist on the importance of the ecosystem's local history in the way in which it is able to respond to global change and, especially, to the increasingly important effects of droughts. "Just like the recovery from an infection differs if it's the first or second time your body is fighting against it, two ecosystems can seem identical but not be so because of their personal histories", Doblas explains.

The following table shows the list of the 13 scientific challenges organised into umbrella categories of five predominant questions:

How does the concurrence of various global change phenomena affect ecosystem function?
1	Understand how the typical mosaic form of the Mediterranean landscape affects forest fire propagation.
2	Understand the combined effects of different phenomena comprising global change on biological invasions and the expansion of plagues.
3	Understand the interaction between the phenomena comprising global change and most recent forest management practices.
How can we improve the quality of data gathered on the response of the ecosystem to global change?
4	Obtain more realistic information (at larger spatial and temporal scales) of the impacts of global change on services provided by the ecosystem.
5	Improve the assessment of tree mortality associated with climate extremes, with particular interest on drought phenomena.
Can we manage ecosystems so that they are more resistant to global change?
6	Identify and manage the areas most vulnerable to global change.
7	Use ecosystem functioning and history to study its capacity to return to an initial state following a perturbation (resilience).
8	Open research to other fields to study the importance that genetics could have on this resilience capacity.
Will we lose services provided by ecosystems if their internal functioning is changed?
9	Study how forest management can improve ecosystems' capacities to store carbon and water in the long term and large scale.
10	Analyse how biodiversity changes when the landscape changes.
Does the same happen in the short term and local scale as in the long term and regional scale?
11	Increase the precision of models of prediction of global change by including the influence of socio-economic context.
12	Carry out manipulative and interdisciplinary experiments at different scales to understand the interaction between forests and the atmosphere.
13	Improve understanding of how water availability at the landscape scale affects plants' hydraulic systems.

Thirteen new challenges which substitute 25 challenges proposed by Sandra Lavorel in 1998

In order to identify these 13 challenges the researchers did not begin from zero; instead, they analysed the degree of satisfaction of challenges posed 16 years ago in a similar article, published in the same journal by the scientist Sandra Lavorel. Of the 25 challenges posed in 1998, nine have been successfully achieved, and only two remain unanswered. The remaining 14 (the majority) have only been answered in part (see following table):

What will future fire regimes be like?		Accomplishment
1	Predict wildfires based on soil use.	Partial
2	Predict wildfires based on climate.	Yes
3	Predict wildfires based on the influence of atmospheric composition.	No
4	Measure impacts of wildfires on the landscape.	Yes
5	Measure impacts of wildfires on vegetation.	Partial
6	Measure impacts of wildfires in the context of climate change.	Yes
7	Measure the impacts of wildfires on ecosystem function.	Partial
8	Control wildfires using prevention.	Yes
9	Control the effects of wildfires using restoration.	Partial
How do living beings interact with the atmosphere?
10	Understand how soil use interacts with climate.	Partial
11	Understand how physiology of living beings interacts with atmospheric CO2 and the planet's temperature.	Partial
12	Understand the interaction between gasses emitted by living beings and the planet's temperature.	Partial
13	Understand the interaction between gases emitted by wildfires and the atmosphere.	Yes
14	Create models which work with all of the above data.	Partial
How does water availability affect the landscape?
15	At the small parcel or patch scale, understand how physiology such as leaf surface affects water circulation in plants.	Yes
16	At the small parcel or patch scale, understand the hydrologic equilibrium.	Partial
17	At the small parcel or patch scale, study how the quantity and quality of water changes with time.	Partial
18	At the small parcel or patch scale, create simulation models which work with the above data.	No
19	At the landscape scale, make water availability maps.	Yes
20	At the landscape scale, check to see if patterns and effects are similar to the small scale.	Yes
21	At the landscape scale, study the effects of landscape change on water availability.	Yes
22	At the landscape scale, create simulation models which work with the above data.	Partial
How is biodiversity changing?
23	Understand changes in genetic diversity.	Partial
24	Understand changes in species diversity.	Partial
25	Understand changes in landscape diversity.	Partial

 
The authors wrote the article in the context of the project MONTES-Consolider (CSD2008-00040), financed by the Spanish Ministry of Economy and Competitively. Participating researchers were from CREAF, the Universitat Autònoma de Barcelona, the University of Granada, the Centre Tecnològic i Forestal de Catalunya (CTFC), the Museum of Natural Sciences of the Spanish Council for Scientific Research (CSIC), The University of Castilla-La Mancha, the Center for Mediterranean Environmental Studies (CEAM), the University Rey Juan Carlos I, the University of Macquarie (Australia), the Institut de Diagnosi Ambiental i Estudis de l’Aigua (CSIC), and the University Carlos III de Madrid.
 
Article:  Doblas-Miranda, E., Martínez-Vilalta, J., Lloret, F., Álvarez, A., Ávila, A., Bonet, F. J., Brotons, L., Castro, J., Curiel Yuste, J., Díaz, M., Ferrandis, P., García-Hurtado, E., Iriondo, J. M., Keenan, T. F., Latron, J., Llusià, J., Loepfe, L., Mayol, M., Moré, G., Moya, D., Peñuelas, J., Pons, X., Poyatos, R., Sardans, J., Sus, O., Vallejo, V. R., Vayreda, J. and Retana, J. (2015), Reassessing global change research priorities in Mediterranean terrestrial ecosystems: how far have we come and where do we go from here?. Global Ecology and Biogeography, 24: 25–43. doi: 10.1111/geb.12224