滇中地区土壤有效磷含量对植物理化性质的影响

以滇中地区昆明、玉溪和曲靖3市所属12个县（市、区）的云南松、矮杨梅、牛尾蒿等32种主要森林植物为研究对象，共采集了32种346批次叶（茎）、17种43批次枝及对应植物根部土壤为实验样品，测定了其抽提物含量、灰分含量、热值和土壤有效磷含量，分析了土壤有效磷含量对植物理化性质的影响，进而研究了土壤有效磷含量对植物燃烧性的影响。结果表明：（1）土壤有效磷在一定程度上增加叶的抽提物含量和热值，降低叶灰分含量，但枝理化性质对土壤有效磷含量的响应不及叶明显；（2）滇青冈、华山松、黄茅、南烛、牛尾蒿、野八角、银荆、云南樟的叶理化性质对土壤有效磷含量响应较灵敏，云南油杉和云南樟的枝理化性质对土壤有效磷含量响应较灵敏，土壤有效磷也能相对明显地增加云南松、华山松、地盘松、牛尾蒿、紫茎泽兰等滇中地区常见植物枝、叶（茎）的抽提物含量和热值，降低他们的灰分含量；（3）在生境相似的条件下，土壤有效磷含量与抽提物含量、热值呈显著正相关关系。土壤有效磷能够在一定程度上增加植物的粗脂肪含量和热值，降低其灰分含量。这种变化趋势有利于植物燃烧性的提升。并就加强滇中地区森林火灾风险治理提出相应的措施与建议。

Study on the effect of soil available phosphorus content on the physicochemical properties of plants in central Yunnan

In order to study the effect of soil available phosphorus content on the physicochemical properties of plants, 32 major forest plants as the research objects include Pinusyunnanensis, Myrica nana and Artemisia dubia Wallich. They are from Kunming, Yuxi and Qujing (include 12 counties, cities or districts) in the central Yunnan region. A total of 346 batches of leaves (stems) of 32 species, 43 batches of branches of 17 species，and corresponding plant root soil were collected as experimental samples. The extract content, ash content, calorific value and soil available phosphorus content were determined, and analyzed the effect of soil available phosphorus content on the physicochemical property of plants, and then studied the effect of soil available phosphorus content on the combustibility of plants. The results showed that: (1) Soil available phosphorus increased leaves extract content and calorific value to a certain extent, and reduced its ash content, but the physicochemical properties of the branches have less response to the soil available phosphorus content than the leaves; (2) The leaves physicochemical properties of Cyclobalanopsis glaucoides, P. armandii,Heteropogon contortus, Lyonia ovalifolia, Artemisia dubia, Illicium simonsii, Acacia dealbata and Cinnamomum glanduliferum responded more sensitively to soil available phosphorus content, and the branches physicochemical properties of Keteleeria evelyniana and Cinnamomum glanduliferum responded more sensitively to soil available phosphorus content, and available phosphorus in soil can significantly increase the extract content and caloric value of branches and leaves (stems) of common plants in central Yunnan, such as Pinus yunnanensis, P. armandii, P. yunnanensis var. pygmaea, Artemisia dubia and Eupatorium adenophorum, and reduce their ash content; (3) Under similar habitat conditions, the soil available phosphorus content and extract content, calorific value are significant positive relationship. Soil available phosphorus can increase the crude fat content and calorific value of plants to a certain extent, and reduce their ash content. This change trend is conducive to the improvement of the combustibility of plants. Based on this, the corresponding measures and suggestions are put forward to strengthen forest fire risk management in central Yunnan.