| Creature will try a bound of method to adapt environment change. This coping mechanisms called life history strategy. Different species used different way to acclimatization, these way leading to lots of life history strategy form. All the way should make specie reproductive success and biggest.Study on current-year twig is heleful to understand functional traits of plant. Plant is a component organism, that many complex component play as a whole unit on physiological effect. Current-year twig could be an independent component unit of plant growth, with some autonomy. Current-year twig stand for whole plant role in sometime, and explaining some functional change of each part of twig.Various environmental factors are main elements to influence physiological ecology traits for plant, and complex environment along altitude gradient will make different result on different region. Because of complex landform, water or heat condition changed along altitude in subtropical mountain land. Made it became a good place to study on plant life history strategy. Jiangxi Wuyi Mountain National Nature Reserve located in Jiangxi, China. It's a ideal region to study plant traits change along altitude gradient. Because of its mid-subtropical mountain land ecosystem, and have a rich biodiversity forest, obvious variation of community on vertical direction.Pinus taiwanensis Hayata was an endemic trees of China. It was a main tree which used to afforest and ecological restoration on east subtropical high altitude mountain land, China. Pinus taiwanensis Hayata had ecological succession function in mid-mountain, far better than Pinus massoniana Lamb. Pinus taiwanensis Hayata could be used in vegetation recovery, carbon sequestration, water conservation, exploit needle efficacy, and to reply global climate change.Therefore, we chose current-year Pinus taiwanensis Hayata swig, thorough it traits expression and tradeoff between traits, discuss Pinus taiwanensis Hayata swig adaption strategy under different environment.Main results:On the biomass location within twigs, total lamina mass and stem accounted for 79.62% and 20.38% of the total twig biomass, respectively. High altitude ratio of total lamina mass and the twig mass significant lower than low altitude (p<0.05), with large changes in different season. Leaf mass per aera on high altitude significant lower than low altitude (p< 0.05), except the December of 2014.Pinus taiwanensis current-year twigs had a allometric about stem mass and leaf mass on high altitude (2000m) or low altitude (1200m) (Allometric index<1, p< 0.05), stem mass growth faster than leaf mass. However, whole scaling relationships between leaf biomass and stem biomass is nearly uniform (Allometric index?1.0). From season view, early growing season (Jun.2015) stem mass increase faster than leaf mass (Allometric index<1, p< 0.05), but uniform in the end of growing season (Dec.2014) (Allometric index?1.0).Leaf size (measure by leaf mass) and leaf number (leafing intensity) was negative allometric (Allometric index<-1.0). Early growing season (Jun.2015) leaf size and leafing intensity was negative allometric (Allometric index=-0.627), but there was a negative allometric on late growing season (Dec.2014) (Allometric index ?-1.0). Relationship of leaf size and number showed a negative uniform on middle altitude (1600m), however was allometric on low altitude (1200m) or high altitude (2000m)(Allometric index>-1).In the stem architecture, at the fast growth period (Jun. and Sept.2015) the ratio of stem length and stem diameter significant lower than other seasons (p< 0.05), indicated that the growth of stem was given priority to with radial direction in the growth season. Stem wood density was also significantly lower, which is associated with the rapid growth of stem volume. In addition, stem wood density showed a result that low altitude (1200m,1400m) significant higher than high altitude (1800m, 2000m)(p<0.05).Allometric equation of Stem length (or stem diameter) and leaf mass showed: when stem length and diameter increased, the growth exponents of total lamina mass were 1.74,2.862, respectively, suggesting that the growth of stem was significantly promote the growth of leaves, especially the stem diameter (2.862>1.740). The stem length/diameter ratio was one of the indicators to measure plant apical dominance, however, the apical dominance gains at the cost of the reduction of leaf biomass.The C:N:P ratios in stem and leaf were 422:9:1 and 435:13:1, respectively. The C content of leaf and stem was non-significant, but both the leaf N contend and P content were higher than stem. Whether leaf or stem of N, P content, the high altitude were significantly higher than the low altitude (p<0.05). Inside the stem and leaf, N content allometricl scaled to P content with a slope 0.732 and 0.771, respectively. Besides, the C, N, P content and C:N ratio of the stem were faster than the leaf.In general, although the leaf biomass occupied the main part of current-year twigs biomass, but the results showed that the coping strategies of Pinus taiwanensis Hayata was usually achieved by changing the stem traits, when facing environmental stress (too high or low altitude). In addition, whether in the growing season had great influence for the performance of the characteristics of Pinus taiwanensis Hayata twig. |
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