典型喀斯特区不同覆盖下顶坛花椒林地生态需水量研究

对典型喀斯特区不同覆盖下顶坛花椒人工林地生态需水量及生态亏缺水量进行了研究。结果表明：在岩石裸露率375 %的100 m2样地内，植物生长发育期间林地土壤含水量为153～185 m3，经枯枝落叶和石面覆盖后分别为156～206 m3和152～192 m3，枯枝落叶覆盖后林地土壤含水量平均增幅与变幅均最大；顶坛花椒在生长发育期总蒸腾量为91962 7 mm，蒸腾耗水量以成熟期最多，开花结果期次之，展叶期最少；林地潜在蒸散量和实际蒸散量分别为51518 3 m3和54950 1 m3，经不同覆盖处理后，蒸散量均下降，其中石面覆盖时减少量多；林地生态需水量为61479 4 m3，经枯枝落叶和石面覆盖后，其生态需水量分别为58424 2 m3和46000 1 m3，而经枯枝落叶覆盖，在顶坛花椒成熟期林地未出现水分亏缺。对不同覆盖条件比较可知，枯枝落叶覆盖下林地水分亏缺量最少，在植物生长发育期抵御干旱的效果相对较好。因此，喀斯特区造林选择枯枝落叶覆盖效果相对较好，而为保证顶坛花椒的产量及质量，在其开花结果期和成熟期应加强土壤水分管理。

The estimation on ecological water requirement of forestland under different mulching plantations in typical Karst area

Ecological water requirement and ecological water shortage of(Zanthoxylum bungeanum var.dintanensis) forestland under different mulching plantations were studied in typical Karst valley area.The results showed that there were 37.5 % of the rocks exposed rate in the 100 m2 plot,its acreage was only 62.5 m2.Range of soil moisture was 1.53—1.85 m3 in the period of growth and development,but it was 1.56—2.06 m3 and 1.52—1.92 m3 by litter mulching and stone mulching respectively,their increasing rates were 6.69 % and 4.32 % respectively,which range average of increase and change of litter mulching was best.Transpiration quantitative was 91.962 7 mm in the period of growth and development,in which transpiration quantitative of show-leaf stage.Their relations: maturity stage>flowering-fruiting stage>show-leaf stage.In order to ensure top yields and quality of Z.bungeanum var.dintanensis,management should be reinforced of soil moisture of flowering-fruiting stage and maturity stage.Potential and reality evapotranspiration of forestland was 51.518 3 m3,54.950 1 m3 respectively in the period of growth and development,but their evapotranspiration decreased,in which stone mulching conspicuous decreased.Ecological water requirement of forestland was 61.479 4 m3 in the period of growth and development,but it was 58.424 2 m3 and 46.000 1 m3 respectively by litter mulching and stone mulching.Ecological water shortage decreases and water shortage didn’t appear by different mulching in the period of maturity.Overall,ecological water requirement of forestland was related with soil moisture,evapotranspiration of forestland and transpiration of plants.Water shortage was lest by litter mulching,and plant would exhibit stronger drought resistance in the growth period.Therefore,afforestation should select lither mulching in karst area,but the relationship between the thickness of mulching and changes of water requirement deserves further study.