The resilience of annual vegetation primary production subjected to different climate change scenarios
- 574 Downloads
We examined if climate change in two dry ecosystems—Mediterranean (DME) and Semiarid (SAE)—would cause substantial reduction in the production of annual vegetation. Field measurements and computer simulations were used to examine the following six climate change scenarios: (1) rainfall amount reduction; (2) increases of 10 % in annual evaporation rate and 5 % in annual temperature; (3) increase in magnitude of rainfall events, accompanied by reductions in frequency and seasonal variation; (4) postponement of the beginning of the first rainfall event of the growing season; (5) long dry spells during the growing season; and (6) early ending of the growing season. The results revealed the following outcomes. a) Reduction by 5–35 % in annual rainfall amount did not significantly affect productivity in the DME, but a large (25–35 %) decrease in rainfall would change vegetation productivity in the SAE and lead to a patchier environment. b) Similar results were observed: when temperature and evaporation rate were increased; when the magnitude of rainfall events increased but their frequency decreased; and during a long mid-season dry spell. c) In both ecosystems, changes in the temporal distribution of rainfall, especially at the beginning of the season, caused the largest reduction in productivity, accompanied by increased patchiness. d) Long-term data gathered during the last three decades indicated that both environments exhibited high resilience of productivity under rainfall variability. These results imply that the response of dry ecosystems to climate change is not characterized by a dramatic decrease in productivity. Moreover, these ecosystems are more resilient than expected, and their herbaceous productivity might undergo drastic changes only under more severe scenarios than those currently predicted in the literature.
KeywordsRainfall Event Rainfall Amount Ecosystem Resilience Rainfall Reduction Annual Rainfall Amount
This research was supported by the Israel Science Foundation (grant No. 692/06), the Advisory Board of Range Management of the Israeli Ministry of Agriculture and Rural Development (grant No. 857049407), the Jewish National Fund (KKL) and the Israeli Ministry of Environmental Protection (grant No. 5-021). Thanks are extended to the Department of Agronomy and Natural Resources of the Volcani Center for sharing with us the biomass and climatologic databases. We thank Rafi Yonathan, Dani Barkai, Hagit Baram and the Ben-Gurion University GILab members for their help with field work in the Lehavim LTER. We appreciate the help of Zalmen Henkin and his team, Amit Dolev and Yehuda Yehuda, with the field work in the Korazim site.
- Daly C, Bachelet D, Lenihan JM, Neilson RP, Parton W, Ojima D (2000) Dynamic simulation of tree-grass interactions for global change studies. Ecol Appl 10:449–469Google Scholar
- Dayan U, Koch J (1999) Implications of climate change on the coastal region of Israel. Mediterranean Action Plan, United Nations Environment ProgrammeGoogle Scholar
- Jensen JR (1996) Introductory digital image processing: a remote sensing perspective. Prentice-Hall Publishing Inc, Englewood Cliffs, p 316Google Scholar
- Oesterheld M, Loreti J, Semmartin M, Sala OE (2001) Inter-annual variation in primary production of a semi-arid grassland related to previous-year production. J Veg Sci 12:137–142Google Scholar
- Schwinning S, Sala OE (2004) Hierarchy of responses to resource pulses in arid and semi-arid ecosystems. Oecologia 141:211–220Google Scholar
- Schwinning S, Sala OE, Loik ME, Ehleringer JR (2004) Thresholds, memory, and seasonality: understanding pulse dynamics in arid/semi-arid ecosystems. Oecologia 141:191–193Google Scholar
- Yosef Y, Saaroni H, Alpert P (2009) Trends in daily rainfall intensity over Israel 1950/1-2003/4. Open Atmospheric Science Journal 3:196–203Google Scholar