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Stand structure modulates the long‐term vulnerability of Pinus halepensis to climatic drought in a semiarid Mediterranean ecosystem
Author(s) -
MORENOGUTIÉRREZ CRISTINA,
BATTIPAGLIA GIOVANNA,
CHERUBINI PAOLO,
SAURER MATTHIAS,
NICOLÁS EMILIO,
CONTRERAS SERGIO,
QUEREJETA JOSÉ IGNACIO
Publication year - 2012
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2011.02469.x
Subject(s) - aridification , mediterranean climate , environmental science , aleppo pine , ecosystem , woodland , stomatal conductance , mediterranean basin , water use efficiency , carbon sequestration , photosynthesis , ecology , agroforestry , climate change , biology , botany , carbon dioxide
We investigated whether stand structure modulates the long‐term physiological performance and growth of Pinus halepensis Mill. in a semiarid Mediterranean ecosystem. Tree radial growth and carbon and oxygen stable isotope composition of latewood ( δ 13 C LW and δ 18 O LW , respectively) from 1967 to 2007 were measured in P. halepensis trees from two sharply contrasting stand types: open woodlands with widely scattered trees versus dense afforested stands. In both stand types, tree radial growth, δ 13 C LW and δ 18 O LW were strongly correlated with annual rainfall, thus indicating that tree performance in this semiarid environment is largely determined by inter‐annual changes in water availability. However, trees in dense afforested stands showed consistently higher δ 18 O LW and similar δ 13 C LW values compared with those in neighbouring open woodlands, indicating lower stomatal conductance and photosynthesis rates in the former, but little difference in water use efficiency between stand types. Trees in dense afforested stands were more water stressed and showed lower radial growth, overall suggesting greater vulnerability to drought and climate aridification compared with trees in open woodlands. In this semiarid ecosystem, the negative impacts of intense inter‐tree competition for water on P. halepensis performance clearly outweigh potential benefits derived from enhanced infiltration and reduced run‐off losses in dense afforested stands.