经营方式对毛竹林养分分布的影响

Nutrient distribution pattern in Phyllostachys edulis forest with different operating management modes in Northwest Fujian

以福建省永安市天宝岩自然保护区不同人为经营方式的毛竹林为研究对象,对毛竹林Ⅰ(挖笋+劈草)、Ⅱ(挖笋+劈草+专用肥)和Ⅲ(挖笋+劈草+专用肥+灌水)的养分元素分布格局进行了研究。结果表明,施肥、施肥+灌水等经营方式增加了植被层的养分累积量质量分数,降低了土壤层养分累积量质量分数,平衡乔木层和土壤层碳氮贮量是森林实现科学经营的关键。施肥+灌水虽然明显增加了毛竹林系统养分元素的累积绝对量,但是增加最多的是K元素,而N、P元素累计量呈降低趋势,氮、磷元素是植物生长发育的必需元素,是系统生产力构成的重要因素,氮、磷元素的减少可能损害竹林持续立地生产能力。3种林分主要养分元素在不同层次的排列顺序均为土壤层>乔木层>凋落物层>灌木层>草本层,土壤层养分累积量占养分总累积量99%以上,植被层中乔木层累积量最高,其在植被层中的质量分数高于85%。

We used Phyllestachys edulis forest under different types of management and protection in Tianbaoyan Nature Reserve of Yong’an city,Fujian province,as research objective,to investigate the nutrient distribution pattern in P.edulis forest I（digging bamboo shoots ＋ weeding）,II（digging bamboo shoots ＋ weeding ＋ fertilizer） and III（digging shoots ＋ weeding ＋ fertilizer ＋ irrigation）.The results showed that the proportion of accumulated nutrient amount in vegetable layer increased,while nutrient accumulated proportion in soil layer decreased in forest II and III.The key to the scientific management was how to balance the nutrients storage in tree layer and soil layer.The amount of accumulated nutrients in forest III increased significantly.However,the increment was attributed to the increase in potassium,while the nitrogen and phosphorus storages were decreased.It was an essential element for nitrogen and phosphorus to the plant growth and development.The long-term productivity of bamboo forest may be damaged with the reduction of nitrogen and phosphorus.The accumulation of nutrient elements in different forest layers was in the order of soil layertree layerlitter layershrub layer herb layer.The proportion of soil layer nutrient accumulation accounted for more than 99% of total nutrient accumulation.The accumulation of nutrient elements in tree layer was highest among those vegetable layers,and accounted for above 85% nutrient element accumulation.