Rainfall partitioning into throughfall and stemflow and associated nutrient fluxes: land use impacts in a lower montane tropical region of Panama
Rainfall partitioning into throughfall and stemflow and associated nutrient fluxes: land use impacts in a lower montane tropical region of Panama
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DOI：
10.1007/s10533-012-9709-0
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发表时间：
2012-11-01
期刊：
影响因子：
4
通讯作者：
Schwendenmann, Luitgard
中科院分区：
文献类型：
--
作者：
Macinnis-Ng, Catriona M. O.;Flores, Eric E.;Schwendenmann, Luitgard
土地利用变化通过影响分区降雨的质量和数量来改变流域水文。我们比较了巴拿马三种土地利用类型[原始林 (PF)、次生林 (SF) 和农业 (A)] 的降雨分配（径流、茎流和拦截）以及降雨、径流和茎流中的养分浓度。径流的测量变化很大，这可能掩盖了季节和土地利用的差异，但很明显，农业地区的径流在总降水量中所占的比例高于森林地区。在事件降水中，94% 成为农业用地的径流，而总降水量的 83% 和 81% 分别成为 PF 和 SF 的径流。降水事件的规模是径流和茎流变化的主要驱动因素。养分循环的一致模式也很难确定。植被在输送养分方面发挥着至关重要的作用，因为钾的径流沉积通常大于降水沉积。冠层预算模型表明，冠层交换通常比干沉降更占主导地位。径流通常富含养分，特别是钾和镁，PF 中钾和镁的富集系数分别高达 17 和 5。相反，Ca 有时会被冠层吸收。养分沉积值很高（PF中Ca、Mg、K和Na的沉积量分别高达15、3、30和15 kg ha(-1)月(-1)），可能是由于该地区刀耕火种的农业做法或海洋投入所致。径流和茎流是这些生态系统中营养物质的重要来源。
Land-use change alters catchment hydrology by influencing the quality and quantity of partitioned rainfall. We compared rainfall partitioning (throughfall, stemflow and interception) and nutrient concentrations in rainfall, throughfall and stemflow in three land-use types [primary forest (PF), secondary forest (SF) and agriculture (A)] in Panama. Measurements of throughfall were highly variable which may have masked seasonal and land use differences but it was clear that throughfall at agricultural sites made up a larger proportion of gross precipitation than at forest sites. Of incident precipitation, 94% became throughfall in agriculture sites while 83 and 81% of gross precipitation became throughfall in PF and SF, respectively. The size of the precipitation event was the main driver of variation in throughfall and stemflow. Consistent patterns in nutrient cycling were also difficult to identify. Vegetation has a vital role in delivering nutrients as throughfall deposition of K was often larger than precipitation deposition. A canopy budget model indicated that canopy exchange was often more dominant than dry deposition. Throughfall was generally enriched with nutrients, especially K and Mg, with enrichment factors of up to 17 and 5 for K and Mg, respectively, in PF. In contrast, Ca was sometimes taken up by the canopy. Values of nutrient deposition were high (with up to 15, 3, 30 and 15 kg ha(-1) month(-1) in stand deposition of Ca, Mg, K and Na, respectively in PF), possibly due to the slash-and-burn agricultural practices in the area or marine inputs. Throughfall and stemflow are vital sources of nutrients in these ecosystems.