Simao Pine Nutritional Characteristics Of Plantation Productivity And Carbon Allocation

Researching nutritional characteristics and plantation productivity and carbon allocation of forest is the key contents of the long-term productivity of plantations to maintain the essential mechanism. Stand productivity, tree growth is closely related to the site conditions, planting algebra and nutrient supply of woodland. Study on nutritional characteristics of trees is the basic of long-term productivity, from the nutritional characteristics could reflect the impact that site conditions, planting algebra and nutrients supply to forest productivity and carbon distribution, provide a scientific theory basis for cultivation of plantation.Pinus kesiya var. langbianensis is an important industrial timber species in southwest China. It is a great significance that nurturing and expanding forest resources of Pinus kesiya, because it can develop the industrial timber in southwest region. Developping Pinus kesiya var. langbianensis is intensive plantation for long term. So it is far-reaching significance for plantations oriented cultivation that study on nutrition characteristics and plantations productivity of Pinus kesiya.This article study on the nutritional characteristics of Pinus kesiya var. langbianensis systematically. Including, the impacts of genesis to soil fertility, soil nutrients to photosynthetic characteristics and tree nutrients, and N, P nutrients to seedling growth, photosynthate distribution, and the diagnosis of nutritional balance, etc. Aim is to provide a theoretical basis for oriented cultivation and tatsu fast of Pinus kesiya var. langbianensis. The results are as follows:(1) By comparative and analysis soil nutrient content of natural forests and plantations of Pinus kesiya var. langbianensis, the results show that the plantation of Pinus kesiya var. langbianensis will lead to reducing soil nutrients, making soil degradation in woodland, but it is different that the nutrients decline at different stages and the degree of declining is with change by index changes.(2) Although in same age and site conditions, natural forest biomass is lower than plantation's of Pinus kesiya var. langbianensis, the proportion of the root biomass in the plantations is increase than the natural, and the proportion of root biomass is lower by status index increased, is adapt to insufficient nutrient, this shows that behalf of the many plantation of Pinus kesiya var. langbianensis is stimulating root development, leading to forest degradation and productivity decline.(3) Nutrients accumulation in different plant organs which is in differences are changing with age, it shows that have enormous impact on nutrients cumulationly. The disciplinarian of nutrients accumulation that is in different site conditions shows, the supply capacity of soil mass nutrient is enhanced with status index improved. And nutrients accumulation in different genesis is increase with age upward, to show the rule is mature forest> Medium-aged forest> young growth.(4) The differences in photosynthetic parameters in different site conditions shows, Pinus kesiya var. langbianensis in good site conditions can endure strong light preferably, utilize light energy efficiently, this is the physiological foundations which is in good site conditions of Pinus kesiya var. langbianensis, have biggish photosynthesis and grow quickly, and it consistents with conditions of nutrient providing amply.(5) Testing Pinus kesiya var. langbianensis seedlings in different level of N nutrition under NP nutrient deficiency. The result is the greatest height growth in the N nutrient of 100%. When N nutrition increased, caused the movement of photosynthetic products accumulation in Pinus kesiya var. langbianensis seedlings from roots to stem; Testing Pinus kesiya var. langbianensis seedlings in different level of P nutrition under NP nutrient deficiency, the result is the best high-growth in 25% for P level, As the P supply increased, caused the movement of photosynthetic products accumulation in Pinus kesiya var. langbianensis seedlings from leaf to root; Testing Pinus kesiya var. langbianensis seedlings in different level of N,P nutrition under N nutrient sufficient and P nutrient deficiency, the result is that there is the largest high-growth in the level NP1, with deliquesce of P nutrition deficiency, the movement of photosynthetic products accumulation in Pinus kesiya var. langbianensis seedlings from roots to stem and leaves, and leaves is primary.(6) Using groups'diagnostic method to diagnose the nutrition balance of N, P and NP fertilizer. The result is, in N nutrition test, k values of all levels is 0.534-0.638, they are less than 1, it showed that seedlings are in a state of nutritional deficiency; in P nutrition test, k value of level P4 is 0.922, up to the status of nutrition equilibrium; because N nutrition is sufficient in NP nutrition test, k value is the bigger, k value of level NP3 is 0.912, closing to 1, and reaching a state of nutrition equilibrium.(7) In order to validate the feasibility of groups diagnosis in field application, when investigating biomass, gathering samples in the woodlang of 14,16 and18 status class, the result showed that k value of 14 and16 status class in young growth is 0.542 and 0.818, they are smaller than 1, didn't up to nutrition balance, but k value of 18 Index is 0.932, close to k= 1, reaching a state of nutrition equilibrium, this showed that the effective fertilization site index is the status class below 18 index for Pinus kesiya var. langbianensis in young growth.