Dynamic Pattern Of The Pinus Massoniana Forest Structure And Ecological Adaptation Of Main Trees In Different Restoring Periods

Evergreen broad-leaved forest is the zone natural vegetation of subtropical regions, and it is an important part of the subtropical terrestrial ecosystems. Evergreen broad-leaved forest of China is the world's main body of the evergreen broad-leaved forest. Over the years, Evergreen broad-leaved forest was was severely damaged because people didn't recognize its function and role clearly. The Pinus massoniana forest is the most common second-growth forests of evergreen broad-leaved forest in China. It is very important to clarify the process and mechanism of restoration of the Pinus massoniana forest for the restoration and reconstruction of the evergreen broad-leaved forest.The study was sited in Anhui Gu Niujiang Nature Reserve. In order to proven the dynamic pattern of change in community stucture in the recovery process of the pine forest, the species composition, community structure, habitat factors of pine forest communities in different restoring stage at Gu Niujiang areas were surveyed via space-time substitution method from July to November in2011. Futherly, to reveal the ecological response of species during the restoring process, Leaf traits, growth date, stem density of main woody plants in the shurb layer of various communities were measured to compare the patterns of change of leaf traits of the pine forest in different restoring stage, and clarify the causes of its pattern. The main conclusions are as follows:(1)With the restoration progress, species richness was descreasing, Shannon-Wiener diversity index was rising overall. The dominance of deciduous trees was declining, and the dominance of evergreen species was increasing in the forest layer. The dominant species of tree layer changed from single one as Pinus massoniana to doubles as Pinus massoniana-Castanopsis eyrei. The vertical structure of community changed obviously, appearing sub-layers gradually. The popultion struture of main dominant species in each community had changed. Pinus massoniana had been unimodal type all along. Castanopsis eyrei growed from L type to Inverse-J type, and other evergreen shrubs also showed a good growth trend.(2)There were significant variations of leaf traits, and stem density of plants in different restorating stage. The growth rate, leaf nitrogen concentration (LNC) and leaf phosphorus concentration (LPC) in plants were significantly higher and the stem density was lower in the plant community which had restorated10years. Leaf lifespan and stem density were higher in the plant community which had restrated5o years. There were also significant variations of leaf traits of dominant species in different communites. As the ordinary species in the communites, during the restrating process, the specific leaf area (SLA) was higer and the leaf thickness(LTH) was lower of Eurya muricata and Loropetalum chinensis which were the common species in different communites.(3)There were significant variations of leaf traits, and stem density in plant of different life-forms. The growth rate and stem density of evergreen species were lower than deciduous species. SLA, LNC and LPC in deciduous species were significantly higher than the evergreen species. LLS and LTH were lower than evergreen ones.(4)Leaf trait indices were significant correlated with growth rate. AB was positively correlated LNC, LPC, LTN and LTP; RGR was correlated with stem denisty. Leaf trait indices were also significant correlated with each other. SLA was correlated negatively with LLS, LDMC and LTH, but postively with LNC and LPC; LLS was positively correlated with LDMC and LTH, negatively with LNC and LPC; LNC was positively correlated with LPC and N/P, negatively with LPC. And LPC was negatively with LTH and N/P.