Increasing Drought Sensitivity and Decline of Atlas Cedar (Cedrus atlantica) in the Moroccan Middle Atlas Forests
Open Access
- 14 September 2011
- Vol. 2 (3), 777-796
- https://doi.org/10.3390/f2030777
Abstract
An understanding of the interactions between climate change and forest structure on tree growth are needed for decision making in forest conservation and management. In this paper, we investigated the relative contribution of tree features and stand structure on Atlas cedar (Cedrus atlantica) radial growth in forests that have experienced heavy grazing and logging in the past. Dendrochronological methods were applied to quantify patterns in basal-area increment and drought sensitivity of Atlas cedar in the Middle Atlas, northern Morocco. We estimated the tree-to-tree competition intensity and quantified the structure in Atlas cedar stands with contrasting tree density, age, and decline symptoms. The relative contribution of tree age and size and stand structure to Atlas cedar growth decline was estimated by variance partitioning using partial-redundancy analyses. Recurrent drought events and temperature increases have been identified from local climate records since the 1970s. We detected consistent growth declines and increased drought sensitivity in Atlas cedar across all sites since the early 1980s. Specifically, we determined that previous growth rates and tree age were the strongest tree features, while Quercus rotundifolia basal area was the strongest stand structure measure related to Atlas cedar decline. As a result, we suggest that Atlas cedar forests that have experienced severe drought in combination with grazing and logging may be in the process of shifting dominance toward more drought-tolerant species such as Q. rotundifolia.This publication has 51 references indexed in Scilit:
- Impact of recent climatic change on growth of low elevation eastern Mediterranean forest treesClimatic Change, 2010
- Climate change impacts and vulnerability of the southern populations of Pinus nigra subsp. salzmanniiTree Physiology, 2010
- A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forestsForest Ecology and Management, 2010
- Widespread Increase of Tree Mortality Rates in the Western United StatesScience, 2009
- Predicting global change impacts on plant species’ distributions: Future challengesPerspectives in Plant Ecology, Evolution and Systematics, 2008
- Impacts of climate change on natural forest productivity – evidence since the middle of the 20th centuryGlobal Change Biology, 2006
- Tree growth as indicator of tree vitality and of tree reaction to environmental stress: a reviewEuropean Journal of Forest Research, 2005
- Patterns of tree dieback in Queensland, Australia: the importance of drought stress and the role of resistance to cavitationOecologia, 2004
- Drought-induced mortality and hydraulic architecture in pine populations of the NE Iberian PeninsulaForest Ecology and Management, 2002
- Amazonian Tree Mortality during the 1997 El Niño DroughtConservation Biology, 2000