Experimental Manipulation of Precipitation Affects Soil Nitrogen Availability in Semiarid Mongolian Pine (Pinus sylvestris var. mongolica) Plantation
Experimental Manipulation of Precipitation Affects Soil Nitrogen Availability in Semiarid Mongolian Pine (Pinus sylvestris var. mongolica) Plantation
复制标题
降水调控实验对半干旱蒙古松人工林土壤氮素有效性的影响
DOI：
10.3390/w9030208
复制
发表时间：
2017-03-01
期刊：
影响因子：
3.4
通讯作者：
Hu, Yalin
中科院分区：
文献类型：
--
作者：
Fan, Zhiping;Tu, Zhihua;Hu, Yalin
在全球气候变化的影响下，世界大片地区的预期降水变化将对干旱和半干旱地区的陆地生态系统产生深远影响。为了探讨生长季降水变化对半干旱生态系统土壤氮有效性的影响，我们通过模拟相对于自然降水（对照）减少30%降水（DRY）和增加30%降水（WET）建立了雨棚和灌溉系统，以测量两个生长季营养匮乏的蒙古松人工林的一些关键土壤过程特性。湿处理和干处理对土壤无机氮的月度浓度均有显著影响，干处理的月度无机氮含量高于对照，湿处理的月度无机氮含量低于对照。干处理降低了月土壤微生物生物量N含量，湿处理提高了月土壤微生物生物量N含量。结果表明，东北科尔沁沙地蒙松人工林土壤水分和养分有效性具有非同步性。降水减少时，蒙松人工林的水分限制植物生长，而降水增加时，氮限制的作用日益重要。微生物生物量中氮的积累是该生态系统氮循环的重要机制。建议在降水减少时尽量减少蒸散，在降水增加时通过保护凋落物增加土壤氮素有效性，以有效管理蒙松人工林。
Expected changes in precipitation over large regions of the world under global climate change will have profound effects on terrestrial ecosystems in arid and semiarid regions. To explore how changes in the amount of precipitation in the growing season would affect soil nitrogen (N) availability in a semiarid ecosystem, we established rainout shelters and irrigation systems by simulating 30% reduced (DRY) and 30% increased precipitation (WET) relative to natural precipitation (Control) to measure some key soil process properties for two growing seasons in a nutrient-poor Mongolian pine (P. sylvestris var. mongolica) plantation. Both WET and DRY treatments significantly affected monthly soil inorganic nitrogen concentrations, which showed a higher inorganic N under DRY than Control in each month and lower in WET than Control. Monthly soil microbial biomass N content was reduced by DRY and raised by WET treatments. The results indicated the asynchrony of the availability of soil moisture and soil nutrients in Mongolian pine plantations at the Horqin Sandy Lands in Northeast China. Water limited plant growth in Mongolian pine plantations when precipitation decreased, and nitrogen limitation became increasingly important when precipitation increased. Accumulation of N in microbial biomass is an important mechanism for N cycling in this ecosystem. To effectively manage Mongolian pine plantations, it is advised that evapotranspiration is minimized when precipitation decreases and that there is an increase in soil N availability by protecting litterfall when precipitation increases.