生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2012年
11期
1800-1803
,共4页
吕锡芝%余新晓*%王贺年
呂錫芝%餘新曉*%王賀年
려석지%여신효*%왕하년
枯落物%地表径流%水化学%变化趋势
枯落物%地錶徑流%水化學%變化趨勢
고락물%지표경류%수화학%변화추세
litter%surface runoff%water chemistry%trend
为研究径流中的养分与植被覆盖的相互关系,通过人工降雨实验,采集流经油松林下枯落物层的地表径流水样,分析枯落物层对地表径流中化学元素及变化趋势的影响.结果表明:不同枯落物覆盖度对径流中总氮浓度的影响较大,随着枯落物覆盖度的增加,径流中总氮含量降低,随降雨时间大致成抛物线形变化,中间出现了一个平稳的过程,表现出增大-平稳-降低-稳定的变化过程.全磷含量极低,随枯落物覆盖度增加有微弱的增加趋势,一方面由于枯落物的覆盖减弱了径流与土壤层的相互作用,减少了土壤层对磷元素的吸附、固定和持留作用;另一方面径流对枯落物中磷元素的冲刷和淋溶,使得径流中的总磷含量随着枯落物覆盖度的增加而增加,而由于磷元素极易被土壤吸附和固定,所以径流中总磷浓度很低,增加趋势并不大,同时随着降雨历时的增加,总磷浓度的变化也不明显,减小的趋势十分微弱.全钾含量随枯落物覆盖度的增加而增加,随降雨时间成显著的线性降低的趋势,线性关系明显,原因是一方面径流量对钾有稀释作用,无枯落物覆盖更容易形成地表径流;另一方面也与枯落物为钾源有关,地表径流对枯落物中钾元素的冲刷也使得枯落物覆盖度高的林地地表径流中钾元素浓度高.同时,由于枯落物层的存在,增加了雨水的入渗,也降低了径流流速,加剧了径流与表层土壤的相互作用,相互作用的结果加速了土壤中的钾元素向径流释放.
為研究徑流中的養分與植被覆蓋的相互關繫,通過人工降雨實驗,採集流經油鬆林下枯落物層的地錶徑流水樣,分析枯落物層對地錶徑流中化學元素及變化趨勢的影響.結果錶明:不同枯落物覆蓋度對徑流中總氮濃度的影響較大,隨著枯落物覆蓋度的增加,徑流中總氮含量降低,隨降雨時間大緻成拋物線形變化,中間齣現瞭一箇平穩的過程,錶現齣增大-平穩-降低-穩定的變化過程.全燐含量極低,隨枯落物覆蓋度增加有微弱的增加趨勢,一方麵由于枯落物的覆蓋減弱瞭徑流與土壤層的相互作用,減少瞭土壤層對燐元素的吸附、固定和持留作用;另一方麵徑流對枯落物中燐元素的遲刷和淋溶,使得徑流中的總燐含量隨著枯落物覆蓋度的增加而增加,而由于燐元素極易被土壤吸附和固定,所以徑流中總燐濃度很低,增加趨勢併不大,同時隨著降雨歷時的增加,總燐濃度的變化也不明顯,減小的趨勢十分微弱.全鉀含量隨枯落物覆蓋度的增加而增加,隨降雨時間成顯著的線性降低的趨勢,線性關繫明顯,原因是一方麵徑流量對鉀有稀釋作用,無枯落物覆蓋更容易形成地錶徑流;另一方麵也與枯落物為鉀源有關,地錶徑流對枯落物中鉀元素的遲刷也使得枯落物覆蓋度高的林地地錶徑流中鉀元素濃度高.同時,由于枯落物層的存在,增加瞭雨水的入滲,也降低瞭徑流流速,加劇瞭徑流與錶層土壤的相互作用,相互作用的結果加速瞭土壤中的鉀元素嚮徑流釋放.
위연구경류중적양분여식피복개적상호관계,통과인공강우실험,채집류경유송림하고락물층적지표경류수양,분석고락물층대지표경류중화학원소급변화추세적영향.결과표명:불동고락물복개도대경류중총담농도적영향교대,수착고락물복개도적증가,경류중총담함량강저,수강우시간대치성포물선형변화,중간출현료일개평은적과정,표현출증대-평은-강저-은정적변화과정.전린함량겁저,수고락물복개도증가유미약적증가추세,일방면유우고락물적복개감약료경류여토양층적상호작용,감소료토양층대린원소적흡부、고정화지류작용;령일방면경류대고락물중린원소적충쇄화림용,사득경류중적총린함량수착고락물복개도적증가이증가,이유우린원소겁역피토양흡부화고정,소이경류중총린농도흔저,증가추세병불대,동시수착강우력시적증가,총린농도적변화야불명현,감소적추세십분미약.전갑함량수고락물복개도적증가이증가,수강우시간성현저적선성강저적추세,선성관계명현,원인시일방면경류량대갑유희석작용,무고락물복개경용역형성지표경류;령일방면야여고락물위갑원유관,지표경류대고락물중갑원소적충쇄야사득고락물복개도고적임지지표경류중갑원소농도고.동시,유우고락물층적존재,증가료우수적입삼,야강저료경류류속,가극료경류여표층토양적상호작용,상호작용적결과가속료토양중적갑원소향경류석방.
In order to discuss the relationship between nutrients in runoff and vegetation cover, through artificial rainfall experiment and collecting surface runoff samples flowing through pine forest litter layer, the effect of litter layer on the chemical elements and trends in surface runoff was analyzed in the study. The results indicated that litter coverage had great effects on total nitrogen concentration in runoff. With litter coverage increasing total nitrogen content decreased in the runoff. It was in a parabolic change with rainfall duration increasing and a smooth process appeared in the middle time. Total nitrogen content presented a trend of increase-balance-decrease stability. The total phosphorus content was very low. It slightly increased with the litter coverage increasing. On the one hand, the coverage of litter weakened the interactions between runoff and soil layer and also weakened the adsorption, fixed and retention effects of soil layer on phosphorus element. On the other hand, this was because erosion and leaching of runoff on phosphorus made the total phosphorus content increasing with the increase of the litter coverage. And also because phosphorus elements can easily be adsorbed and fixed by soil, the total phosphorus concentration in runoff was very low and the increasing tendency was not large. Meanwhile, with rainfall duration increasing, the total phosphorus concentration did not change obviously and decreasing trend was small. Total potassium content increased with litter coverage increasing. It presented a trend of significant linear decrease with rainfall time increasing. Because on the one hand, runoff had a dilution effect on potassium, so without litter cover, it was easier to form surface runoff. On the other hand, the erosion of runoff on potassium also made potassium concentration higher in runoff where litter coverage was high. At the same time, the litter increased the infiltration of rainwater, reduced runoff velocity and raised the interaction between runoff and top soil, which accelerated the release of potassium into the runoff.