title: The mechanism for exclusion of Pinus massoniana during the succession in subtropical forest ecosystems: light competition or stoichiometric homoeostasis?
abstract: Competition for light has traditionally been considered as the main mechanism for exclusion of Pinus massoniana during succession in subtropical forest ecosystems. However, both long-term inventories and a seedling cultivation experiment showed that growth of mature individuals and young seedlings of P. massoniana was not limited by available light, but was strongly influenced by stoichiometric homoeostasis. This is supported by the results of homoeostatic regulation coefficients for nitrogen (HN) and phosphorus (HP) estimated using the measured data from six transitional forests across subtropical China. Among three dominant tree species in subtropical forests, P. massoniana and Castanopsis chinensis had the lowest values of HP and HN, respectively. Therefore P. massoniana cannot survive in the advanced stage due to soil phosphorus limitation and C. chinensis cannot successfully grow in the pioneer stage due to soil nitrogen limitation. Our results support that stoichiometric homeostasis is the main reason for gradual exclusion of P. massoniana from the transitional forest and the eventual elimination from the advanced forest during the subtropical forest succession. Therefore greater attention should be paid to stoichiometric homeostasis as one of the key mechanisms for species exclusion during forest succession.
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Yan
authors.affiliation: 1] Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.affiliation: Hennan University of Animal Husbandry and Economy, Zhengzhou 450046, China.
authors.forename: Xingju
authors.initials: X
authors.lastname: Peng
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Shizhong
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Qianmei
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D002681:China; D065928:Forests; D006706:Homeostasis; D009584:Nitrogen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D028223:Pinus / Q000502:physiology*; D012987:Soil / Q000737:chemistry; D013472:Sunlight; D014329:Tropical Climate
chemical_list: D012987:Soil; D010758:Phosphorus; D009584:Nitrogen