摘要
以沂蒙山区的棕壤为例,利用野外原位模拟降雨试验,在分析荒草地、侧柏林、金银花、山楂园和花生地等5种典型覆被下棕壤坡地径流溶解态氮(DN)、磷(DP)输出特征的基础上,探讨了不同土地覆被类型下棕壤主要理化性质差异对径流DN、DP输出的影响.结果表明,在降雨强度(70mm·h-1)、地形和植被覆盖度等条件较为一致的情况下,5种覆被下棕壤坡地径流DN、DP的平均浓度分别在0.595~1.523mg·L-1和0.071~0.269mg·L-1之间;而径流DN、DP的平均输出率分别在3.92~35.79mg·m-·2h-1和0.65~5.89mg·m-·2h-1之间.表土有机质、有效态氮磷钾养分含量等棕壤化学性质,以及容重和初始含水量等棕壤物理性质是影响径流DN、DP浓度的主要土壤因子,棕壤化学性质对径流DN、DP浓度的影响程度要远大于棕壤物理性质,其中,有机质含量对径流DN、DP浓度的贡献率最大,均达到44%以上;砾石盖度与砂粒含量等棕壤物理属性是影响径流DN、DP输出率的主要土壤因子.侧柏林和山楂园表土养分含量较高,导致其径流DN、DP的平均浓度也显著高于金银花、荒草地和花生地.花生地和侧柏林土壤砂粒含量高,砾石盖度大,土质较粗,这是其径流DN、DP的平均输出率较大的主要原因.金银花具有改良土壤结构的功效,可有效地控制径流中溶解态N、P污染物浓度并减少其输出量,合理调整其空间布局,对于该地区的生态经济发展具有积极的意义.
Field in-situ rainfall simulation tests conducted on brown earths from the Yimeng mountainous area were designed to analyze the output characteristics of dissolved nitrogen and phosphorus(DN and DP) in runoff from five typical land cover types(weeds,arborvitae,honeysuckle,hawthorn and peanut),as well as to investigate the effect of the physicochemical properties of brown earths from different land covers on the output of DN and DP.The results showed that,under the same conditions of rainfall(70 mm · h-1),terrain and vegetation coverage,the concentrations of DN and DP from the above-mentioned land were 0.595~1.523 mg · L-1 and 0.071~0.269 mg · L-1,respectively,while the output rates for DN and DP were 3.92~35.79 mg · m-2 · h-1 and 0.65~5.89 mg · m-2 · h-1,respectively.Brown earth chemical properties,including the level of organic matter,available nitrogen,phosphorus and potassium,and physical properties,such as bulk density and initial moisture content,were the main factors influencing the DN and DP concentrations in runoff.The degree of influence of soil chemical properties on the DN and DP concentrations was far greater than the physical properties.Among the chemical factors,soil organic matter level makes the greatest contribution to the dissolved nitrogen and phosphorus concentrations,which were all higher than 44%.For the runoff output rate of DN and DP,the levels of soil rock fragments and sand grain were the fundamental soil factor.The nutrient-rich topsoil under arborvitae and hawthorn resulted in higher DN and DP concentrations in runoff than that from the weeds,honeysuckle and peanut.Due to the large number of soil rock fragments and sand grain in arborvitae and peanut,the runoff output rates of DN and DP on these two lands were also high.Because of the function of improving soil structure,honeysuckle can effectively control the dissolved nitrogen and phosphorus concentrations in runoff and reduce its output by runoff.Therefore,rationally readjusting the spatial pattern of honeysuckle has a positive role in promoting the development of the ecosystem in this area.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第7期1526-1536,共11页
Acta Scientiae Circumstantiae
基金
教育部新世纪优秀人才支持计划项目(No.NCET-08-0877)
山东省科技攻关项目(No.2009GG10006015)
临沂市重大科技创新项目(No.080101003)~~
关键词
沂蒙山区
降雨试验
棕壤理化性质
溶解态氮磷
输出特征
Yimeng mountainous area
rainfall simulation test
brown earths physicochemical properties
dissolved nitrogen and phosphorus
output characteristic