With the continuing disturbance of climate change, there has been a rush amongst ecologists to understand how the predicted changes will affect species. This is because the better we understand how species will be affected, the better we can predict and plan for our future. While climate change did not come into the mass consciousness until relatively recently, it has been affecting ecology for quite some time. Jump et al. (2006) consider how increasing temperatures have been affecting trees at their southern range limits in their paper 'Rapid climate change-related growth decline at the southern range edge of Fagus sylvatica''.
Fagus sylvatica, the European beech, ranges throughout western Europe and finds its southern limit along the Mediterranean. This tree species is not drought tolerant and only grows at elevations higher than 600 meters at its southern limits. In the Mediterranean, temperatures have been rising whilst precipitation patterns have remained stable in the same period. At the time of publication, reports indicated that decline in low elevation populations was occurring, which spurred on this investigation by Jump et al. The authors showed that since 1975, there have been declines in European beech growth in its southern range. The reason for this decline being that increasing temperatures coupled with stable precipitation amounts have induced a drought response in populations. Higher temperatures require trees to imbibe more water. If a species is in an environment where precipitation is close to being a limiting resource, increasing temperatures can push precipitation into a limiting function.
This paper is a case where, in the southern range limits, previously non-stressful abiotic conditions can become stressful as the climate rapidly shifts. The phenomenon of induced drought response as a consequence of increasing temperatures could be a widespread issue for plant species as precipitation patterns are not necessarily expected to follow the increases in temperatures. In environments like the one in this paper, drought tolerant species will be selected for, which will undoubtedly shift the ecology of these environments.
Paper reference:
Jump A.S., Hunt J.M., Penuelas J. (2006). Rapid climate change-related growth decline at the southern range edge of Fagus sylvatica. Global Change Biology. 12(11): 2163 - 2174.
Comentários