凉水和帽儿山地区低级溪流生境和水质状况

为研究不同植被景观土地利用下低级溪流的生境状况和水质差异，对凉水国家级自然保护区红松原始林内和帽儿山国家森林公园境内天然次生林植被和农田背景下各3条溪流生境和水质状况进行调查。对溪流生物特性（悬浮藻、附着藻）和理化性质（温度、混浊度、溶解氧（DO）、pH、NH4^＋-N、NO3^-N、PO4^3-P、总氮（TN）和总磷（11P））以及细小颗粒有机物质（FPOM）和粗大有机物质（CPOM））进行测定。研究结果表明，凉水地区原始林溪流的生境状况好于帽儿山地区的次生林，帽儿山地区农田溪流生境最差。原始林溪流具有稳定的溪底生物生活基质，稳水区和急流区均匀分布，稳水区尺度变化大，受淀积物沉降干扰小，河道较弯曲，河岸稳定，河岸植被覆盖度高；次生林溪流以急流区为主，稳定基质相对较差，并受到一定程度的淀积物沉降干扰，河岸尚稳定，有一定程度的人为干扰；农田溪流基质不稳定，受到强烈淀积物沉降影响，渠道化严重，河岸带植被严重破坏。3种景观背景下溪流总磷（11P）、溶解氧（DO）、混浊度、温度、氮磷比值（N／P）（P〈0．05）存在显著差异。原始林溪流NH4^＋、DO、TP、TN、悬浮藻浓度和pH较高、附着藻数量较多，温度较低、FPOM和CPOM的数量较少；次生林溪流的NO3^--N、N／P和TDIN较高。 浊度较低；农田溪流浊度、温度、PO4^3--P较高，DO和pH较低，附着藻数量较少。景观尺度上的土地利用对溪流生境具有深刻的影响，同时决定溪流的水质状况。

Habitat assessment and water quality analysis of low order streams in different landscapes in Liangshui and Maoershan, Heilongjiang, China

A study was conducted to determine the habitat features and water quality of the streams in different landscapes in Korean pine old-growth forest(Liangshui National Reserve),second growth forest and cropland(Maoershan National Park),Heilongjiang,China.The suspending algae,periphyton algae,temperature,turbidity,dissolved oxygen(DO),pH,NH 4-N,NO-3-N,PO3-4-P,total nitrogen(TN),total phosphorus(TP),total dissolved in organic nitrogen(TDIN),fine particulate organic matter(FPOM),and coarse particulate organic matter(CPOM)of the streams were measured for evaluation of water quality.Results showed that the habitat feature of stream in old growth forest was better than that of stream in second growth forest,while the habitat status of stream in cropland land was worst.Stream in old growth forest was found with more stable streambed substrate for invertebrates and characterized by evenly positioned pools and riffles,greater variation of pool size,less disturbance of streambed sedimentation,more sinuous stream channels,and stable riparian area with greater vegetation coverage.Stream in second growth forest was dominated by riffles,with less stable streambed substrate,easily influenced by sedimentation and its riparian area was relatively stable but frequently disturbed by human activities.Stream in cropland had unstable streambed substrate,heavily affected by sedimentation,high channelization and devegetated riparian area.There were significant differences(p<0.05)in TP,DO,turbidity,temperature and N/P ratio between the streams under different land uses.The concentrations of NH 4,DO,TP,TN and suspended algae as well as pH were higher,quantity of periphyton algae was larger,temperature was lower,and the amounts of FPOM and CPOM were greater in the stream of old growth forest than in the streams of second growth forest and cropland.Comparatively,stream at second growth forest had higher concentrations of NO-3 and TDIN,bigger N/P ratio,with lower turbidity,while the stream at cropland had higher concentration of PO3-4-P,lower concentration of DO and less quantity of periphyton algae,with greater turbidity,higher temperature and lower pH.The study indicated that land use in landscape scale profoundly determine the in-stream habitat and the water quality as well.