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1.
The structure, function and dynamics of reed-belts from three ‘Bornhoeved-Lakes’ was investigated by using methods from vegetation science and molecular biology. Between 1992 and 1994 the morphometry and production of Phragmites was measured at twelve locations, differing in sedimentology and hydrochemistry. The development and production of the plants, as well as the nutrient uptake and relocation, were similar throughout the years within each of the twelve plots. Differences in stand-structure and amounts of nutrients occurred between the habitats. Nitrogen content in the plant material varied between 5 and 30 g N m−2 and phosphorus between 0.3 and 1.2 g PO4-P m−2.80 natural reed habitats were measured for Restriction Fragment Length Polymorphisms (RFLPs) in order to identify the genetic diversity of Phragmites within the lakes. A cluster analysis exhibited groups with high, as well as groups with low genetic similarity. Even if genetically similar, the habitats were not necessarily directly neighboured at the shoreline. A discriminance analysis showed 40% correspondence of the genetic groups with their phenotype and habitat parameters. 相似文献
2.
实验设计中试水槽装置,模拟研究2种沉水植物轮叶黑藻(Hydrilla nerticillata)和苦草(Vallisneria natans)对农村水体的净化效果,并探讨沉水植物在水体氮、磷去除中的作用.结果显示,沉水植物系统均能显著降低水体中总氮、铵态氮、硝态氮和磷酸盐浓度,去除率分别达到50.5%、84.4%、41.9%和64.6%,且轮叶黑藻组选择20 g/m2,苦草组选择40 g/m2为适种密度.水体流经各串联单元时氮、磷去除负荷存在显著差异,其中总氮、硝态氮、磷酸盐浓度在有植物单元高于无植物单元,铵态氮浓度相反,结合单元内溶解氧浓度、硝化与反硝化细菌总数表明,有植物单元可显著发生反硝化作用,无植物单元可显著发生硝化作用,有无植物串联单元更有利于氮的去除. 相似文献
3.
Xiaoying Chen Lin Chen Xinguo Yang Minlan Li Shuangqi Yang Dian Yu Naiping Song 《水文研究》2024,38(5):e15159
Understanding the water use characteristics and water relationship of coexisting vegetation in a mixed-species plantation of trees and shrubs is crucial for the sustainable restoration of degraded arid areas. This study investigated the water use characteristic of coexisting sand-binding vegetation combinations in the sierozem habitat (Populus przewalskii Maxim namely Populus-S and Caragana liouana) and aeolian sandy soil habitats (Populus przewalskii Maxim namely Populus-A and Salix psammophila) of the desert steppe. By analysing the δ2H and δ18O isotopes in xylem, soil water, groundwater and precipitation, a Bayesian MixSIAR model was employed to quantitatively assess the water utilization characteristics of plants. Throughout the growing season, in the sierozem habitat, C. liouana exhibits the highest efficiency in utilizing soil moisture above 60 cm (53.45%) and displays adaptable water use strategies. In contrast, Populus-A predominantly relies on deep soil moisture below 60 cm plus groundwater (63.89%). In the aeolian sandy soil habitat, both Populus-A and S. psammophila similarly favour deep soil moisture below the 60 cm soil plus groundwater (66.77% and 67.60%, respectively). During the transition period from the dry to the wet seasons, although both Populus-A and S. psammophila in the aeolian sandy soil habitat shifted their water sources from deeper to shallower ones, there was considerable overlap in the water sources used by Populus-A and S. psammophila. This overlap led to competition for water resources and exacerbated the depletion of deep soil moisture in both seasons. Conversely, in the sierozem habitat, the partitioning of water sources between Populus-S and C. liouana facilitated the allocation and utilization of water resources between the two species. The findings highlight the need for species-specific consideration in water resource allocation within mixed-species plantations of trees and shrubs, which is crucial for sustainable vegetation restoration in sand-binding ecosystems. 相似文献
4.
黑线姬鼠(Apodemus agrarius)是广泛分布于我国的主要农田害鼠之一,2003年三峡工程开始蓄水后洞庭湖湖滩鼠类群落结构发生了演变,黑线姬鼠已大量侵入湖滩,且逐步成为湖滩生境鼠类群落的优势鼠种。动物在新生境中的繁殖状况是了解其对环境适应的关键指标。为掌握黑线姬鼠种群侵入湖滩生境后的适应情况,为其种群动态的预测预报提供科学依据,本文对2003—2020年洞庭湖湖滩和农田生境中捕获的黑线姬鼠繁殖状况进行比较分析,并结合季节动态和生境差异等因子分析了该鼠在繁殖方面对湖滩生境的适应。结果表明:(1)湖滩生境中黑线姬鼠平均繁殖指数(0.71±0.27)低于农田生境(1.21±0.47),在2016—2020年湖滩上黑线姬鼠的繁殖指数为0.99,略高于农田的0.96;(2)湖滩生境较农田生境中的孕鼠在繁殖中偏向有更多的胎仔数,有6只以上胎仔数的孕鼠占比(65.59%)高于农田生境(49.10%);(3)湖滩生境中发现有幼年组的黑线姬鼠参与繁殖,其繁殖指数、参产率、怀孕率及雄鼠的睾丸下降率随年龄递增;(4)春季和秋季是湖滩生境中黑线姬鼠的主要繁殖季节,其繁殖指数、参产率、怀孕率都显著高于... 相似文献
5.
Characterization of hydraulic suitability of Chinese sturgeon (Acipenser sinensis) spawning habitat in the Yangtze River 总被引：1，自引：0，他引：1
Hydrodynamic flow fields affect the ecological processes such as the water diversity and the distribution of organisms. Understanding the hydrodynamic and ecological processes is critical for the restoration and protection of especially fragile ecological habitats in river systems. This study uses turbulent flow to characterize the ecological behaviour of Chinese Sturgeon (Acipenser sinensis) in the Yangtze River. The Delft3D‐Flow model, which is first validated with field‐measured data, is used to simulate the flow field within spawning habitats of Chinese Sturgeon, downstream of Gezhouba Dam. The model‐simulated turbulent kinetic energy (TKE) and its distribution pattern are then used to characterize the hydraulic environment of the fish's spawning habitat. For the spawning habitat, downstream of Gezhouba Dam, the lower limit of TKE for the Chinese Sturgeon egg mass field is 0.025 m2/s2, which occurs at a velocity less than 1.7 m/s. Chinese Sturgeon prefers habitats with TKE range of 0.010 ~ 0.015 m2/s2 for resting. This suggests that discharge regimes provide the basis for ecological regulation of the Three Gorges Reservoir and the scientific reference for river management. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
6.
Rainer Putz 《Aquatic Sciences - Research Across Boundaries》1997,59(1):74-93
Chlorophyll a-concentrations, AFWD (ash-free-dry-weight) and photosynthesis rates were estimated for periphyton assemblages in Amazonian black-and white-water habitats over 14 months. Cellulose-acetate strips were incubated in situ and showed few major differences in periphyton quality as compared to natural substrata. The only exceptions were submersed Igapó forest leaves, which exhibited higher proportions of green algae and cyanobacteria though not producing differences in total periphyton biomass. Enclosure experiments showed a considerable nutrient release by inundated non-senescent Igapó forest leaves. Periphyton biomass and productivity were found to be highest in black-and white water mixing zones, where biomass peaked at 41.6 mg Chla/m2 and 19.8 g/m2 AFDW. Production was estimated to be 380 gC/m2·a. Maximum biomass of periphyton in floating meadows was 46 mg Chla/m2 and 10.6 g/m2 AFDW, with an annual production of 170 gC/m2·a. Solimões main channel periphyton values were low: maximum Chla was 7.1 mg/m2, AFDW 0.8 g/m2 and annual production was estimated to be 30 gC/m2. Blackwater periphyton values were lower compared to whitewater and mixed water values but an enlarged trophogenic zone has to be taken into account. Highest Chla content reached 30.9 mg/m2, AFDW 1.43 g/m2. Estimated annual production was 110 gC/m2. Observed mean periphyton productivity of Amazonian blackwater habitats approximately corresponded to mesotrophic attached algae productivity in temperate zones, whereas productivity of whitewater periphyton approached those of temperate eutrophic lakes. The role of periphyton in the Amazon food web is discussed. 相似文献
7.
Marine debris is a global concern that pollutes the world’s oceans, including deep benthic habitats where little is known about the extent of the problem. We provide the first quantitative assessment of debris on the seafloor (20-365 m depth) in submarine canyons and the continental shelf off California, using the Delta submersible. Fishing activities were the most common contributors of debris. Highest densities occurred close to ports off central California and increased significantly over the 15-year study period. Recreational monofilament fishing line dominated this debris. Debris was less dense and more diverse off southern than central California. Plastic was the most abundant material and will likely persist for centuries. Disturbance to habitat and organisms was low, and debris was used as habitat by some fishes and macroinvertebrates. Future trends in human activities on land and at sea will determine the type and magnitude of debris that accumulates in deep water. 相似文献
8.
太湖河蚬时空格局 总被引：14，自引：6，他引：8
2006年12月-2007年11月对太湖河蚬种群进行了周年逐月调查.河蚬在分布区的年均密度和生物量分别为265.7ind./m2和100.9g/m2,在夏、秋季均达到高值.根据壳长频数分布的周年变化,太湖河蚬一年一代,繁殖期主要在5-7月份.河蚬主要分布在贡湖湾、马迹山以南区域、西南湖区和小梅港沿岸区域.分析表明,太湖中河蚬的空间分布表现出明显的差异性,这种差异性受到多种因素的综合影响.在北部梅梁湾和竺山湾湖区湖泊中的低溶氧量是限制河蚬生长的最重要因素;在贡湖湾、马迹山以南湖区和西南部湖区,各种生境条件和底质性质适合河蚬的生长繁殖,其密度和生物量的最高值出现在贡湖湾的中心区域(820.0ind./m2,522.9g/m2);在东太湖湖区浮游植物密度较低,底质中有机质较少,食物来源是影响河蚬分布的较重要因素. 相似文献
9.
Mei Zhang Kexin Ma Tong Liu Lili Tang Amir Abdullah Khan Tong Yang Pufan Zheng Tongtong Wang Jianhua Han Fuchen Shi 《洁净——土壤、空气、水》2020,48(1)
The extension and structure of functional traits variation in response to different soil factors between invasive and native plants are poorly understood. Functional traits and soil factors of the invasive plant Amaranthus palmeri and its coexisting plant Polygonum orientale are investigated under three heterogeneous habitats: roadside (rs), wasteland (wl), and riverbank (rb) in Tianjin, China. The shoot dry weight (SDW) and leaf nitrogen (LN) of A. palmeri are significantly higher compared with P. orientale, while A. palmeri has significantly lower leaf dry weight (LDW), leaf area (LA), leaf carbon (LC), and leaf C/N ratio under different habitats. The larger phenotypic plasticity of A. palmeri is one of the important reasons for their successful invasion to heterogeneous habitats. Similarly, the soil water content (SWC) of both species shows a significant difference (p < 0.05) with maximum in riverbank habitat to lowest in roadside habitat. Soil N/P ratio, C/N ratio, and C/P ratio of rb habitats are significantly lower compared to wl and rs habitats (p < 0.05). A redundancy analysis indicates that SWC is the dominant soil factor affecting the functional traits of A. palmeri and P. orientale. However, A. palmeri forms an environmental adaptation strategy by changing traits of SDW, LN, and leaf C/N ratio, which is different from P. orientale by changing traits of LA and LDW. 相似文献
10.
河蚬(Corbicula fluminea)为太湖优势大型底栖动物,通过受控实验研究其对富营养水体的水质改善效果.根据太湖河蚬的自然丰度设置4组密度处理,分别为无河蚬对照组、低密度河蚬组(生物量为130 g/m2)、中密度河蚬组(260 g/m2)和高密度河蚬组(520 g/m2).结果表明:河蚬滤食显著降低悬浮物浓度与叶绿素a含量,低、中、高密度河蚬组水体悬浮物浓度较对照组分别降低了20.85%、34.90%和53.79%,叶绿素a浓度分别降低了23.29%、48.32%和71.17%;放置河蚬还降低了水体TN、TP浓度,但是中密度河蚬组与高密度河蚬组没有显著差异.分析认为,河蚬通过滤食作用降低水体浊度、改善光照条件,有利于底栖藻类的生长及沉水植物的恢复,对富营养水体的生态修复具有重要意义;就太湖而言,河蚬对水质的改善效果可能受沉积物再悬浮造成的营养盐释放等因素的制约. 相似文献
11.
Based on the regional water resources character, the concept of soil water resources is first redefined, and then associated
with their transfer relationship in the hydrological cycle, Evapotranspiration (ET)-based consumption structure and consumption efficiency of soil water resources are analyzed. According to ET’s function in productivity, the consumption efficiency of soil water resources is divided into three classes: high efficient
consumption from vegetation transpiration, low efficient consumption from soil evaporation among plants with high vegetation
coverage and inefficient consumption from soil evaporation among plants with low vegetation coverage and bare soil evaporation.
The high efficient and low efficient consumption were further classified as productive consumption. The inefficient consumption
is considered non-productive consumption because it is significant in the whole hydrological cycle process. Finally, according
to these categories, and employing a WEP-L distributed hydrological model, this paper analyzes the consumption efficiency
of soil water resources in the Yellow River Basin. The results show that there are 2078.89×108 m3 soil water resources in the whole basin. From the viewpoint of consumption structure, the soil water resources are comprised
of 381.89×108 m3 transpiration consumption from vegetation and 1697.09×108 m3 evaporation consumption from soil among plants and bare soil. From the viewpoint of consumption efficiency, soil water resources
are composed of 920.11×108 m3 efficient consumption and 1158.86×108 m3 of inefficient consumption. High efficient consumption accounts for 41.5 percent of the total efficient consumption of the
whole basin, low efficient for 58.5 percent. Furthermore, consumption efficiency varies by region. Compared with ET from different land use conditions, the whole basin appears to follow the trend of having the greatest proportion of consumption
as inefficient consumption, followed by low efficient consumption, and then the least proportion as high efficient consumption.
The amount of inefficient consumption in some regions with vegetation is less than in other regions without vegetation. The
amount of inefficient consumption in grasslands is much greater than in forestlands. However, the proportion of low efficient
consumption is the greatest in crop fields. The amount of high efficient consumption in grasslands and forelands is similar
to the corresponding low efficient consumption. However, the low efficient consumption in grasslands is larger than in the
forelands. Therefore, when adjusting the utilization efficiency of soil water resources, vegetation coverage and plant structure
should be modulated in terms of the principle of decreasing inefficient consumption, improving low efficiency ET and increasing high efficiency ET according to area character.
Supported by the Project of the National 973 Program of China (Grant Nos. 2006CB403404 and G1999043602), the Project of the
National Science Research for the 11th Five-Year Plan (Grant No. 2006BAB06B06), and the Innovation Team Project of the National
Natural Science Foundation of China (Grant No.50721006) 相似文献
12.
13.
Janine Rüegg Courtney M. Currier Dominic T. Chaloner Scott D. Tiegs Gary A. Lamberti 《Aquatic Sciences - Research Across Boundaries》2014,76(4):623-632
Decomposition incorporates organic material delivered by Pacific salmon (Oncorhynchus spp.) into aquatic and terrestrial ecosystems of streams where salmon spawn. We hypothesized that salmon tissue decomposition would be faster, and macroinvertebrate abundance and biomass higher, in terrestrial compared to aquatic habitats, and this would be reflected in the nutritional quality of the tissue. Salmon tissue in coarse-mesh bags was placed in four habitats [terrestrial: riparian (RIP), gravel bars (GRA); aquatic: stream sediment surface (STR), buried in sediments (BUR)] in four southeast Alaska watersheds. After 2 (RIP, GRA) or 4 (STR, BUR) weeks of decomposition, tissue dry mass, macronutrient content, and macroinvertebrate colonizer abundance and biomass were determined. Overall, tissue decomposition was rapid (mean k = 0.088 day?1), while nutritional quality remained high based on elemental ratios (mean C:N = 4.9; C:P = 140; N:P = 30), and differed among habitats (Linear-mixed effects model p < 0.05). Macroinvertebrate assemblages colonizing carcasses were unique to each habitat, although Diptera generally dominated. In terrestrial habitats, the dominant macroinvertebrates were Sphaeroceridae (96 % of invertebrate abundance in RIP habitat) and Calliphoridae larvae (98 % in GRA habitat). In aquatic habitats, the dominant macroinvertebrates were Chironomidae (48 % in STR habitat) and Chloroperlidae (72 % in BUR habitat). Macroinvertebrate colonizer abundance and biomass were higher in RIP (mean 286 individuals and 22 mg g?1) than in other habitats (mean 4 individuals and 3 mg g?1) (Friedman p < 0.05). Rapid decomposition rates and high invertebrate biomass, combined with the high nutritional quality of tissue, suggest rapid incorporation of critical salmon nutrients and energy into both aquatic and terrestrial ecosystems. 相似文献
14.
对于不同生长期、不同湿度条件下芦苇(Phragmites australis)茎、叶中多种类型植硅体含量变化的探讨,能够为植硅体形成机理研究和探讨植硅体对气候变化的响应提供理论依据.选取长春市南湖为实验样点,于5—10月在3种不同生境(旱生、季节性水生和水生生境)采集芦苇样品,并分别统计芦苇茎、叶植硅体形态和数量.实验结果显示:首先,茎、叶植硅体组合特征存在明显差异,茎中帽型及个体较大的尖型等植硅体多于叶中,而叶中硅化气孔含量明显高于茎中.其次,随着植株的生长,芦苇茎中硅化气孔含量先增加后减少,鞍型植硅体含量变化较小而帽型植硅体含量先减少后增加,棒型植硅体含量逐渐增加、尖型植硅体含量先增加后减少;芦苇叶中硅化气孔含量持续增加,鞍型、帽型等短细胞植硅体含量下降,尖型、扇型等个体较大的植硅体含量逐渐增加.最后,不同植硅体类型的含量在3种生境中的变化情况较为复杂,茎中植硅体的数量变化没有明显规律,而芦苇叶中硅化气孔含量由旱生生境向水生生境逐渐增加,可见叶中硅化气孔含量的增加可以指示相对湿润的生境条件.总之,芦苇茎、叶内不同类型植硅体的数量对植株生长及不同湿度环境有不同程度的响应,对芦苇植硅体的研究也有助于理解湿生植物植硅体与环境因子的关系,进而为探讨植硅体对古环境、古气候的响应提供理论基础. 相似文献
15.
摄食栖息地面积是反映越冬水鸟生存空间的直接指标,三峡水库运行后洞庭湖枯水期水文节律出现新的变化,给越冬水鸟摄食栖息地造成的影响尚不明确.为定量描述三峡水库枯水期不同出库流量对洞庭湖越冬水鸟摄食栖息地的影响,以洞庭湖典型的珍稀越冬水鸟——白鹤(Grus leucogeranus)为指示性候鸟,以白鹤摄食对栖息地水深需求作为关键生态因子,建立白鹤摄食对水深需求的栖息地适宜度模型.构建涵盖长江干流、三口河系、洞庭湖及其四水尾闾河段的江湖一体化耦合水动力模型,实现栖息地水动力分布特征的精确模拟.在此基础上耦合栖息地适宜度模型和水动力模型,建立了面向白鹤摄食对三峡水库出库流量需求的物理栖息地模型,量化不同出库流量对应的白鹤摄食栖息地加权可利用面积,定量分析水库运行对白鹤摄食栖息地面积的影响.结果表明:1月中旬三峡水库不同出库流量下洞庭湖白鹤潜在摄食栖息地面积保持稳定并随出库流量的增加呈增大趋势,维持在101.40~121.84 km2之间,其中东洞庭湖摄食栖息地面积在7.49~9.86 km2之间,南洞庭湖(含横岭湖)摄食栖息地面积在47.37~60.34 km2之间,西洞庭湖摄食栖息地面积在46.54~51.64 km2之间.不同湖区摄食栖息地面积随着三峡水库出库流量的增加均呈增大的趋势,说明三峡水库枯水期补水调度对于维持栖息地面积具有重要作用.较三峡水库运行前相比,白鹤摄食栖息地面积最大增加20.44 km2,对应的增幅为20.16%.成果明晰了三峡水库运行对洞庭湖白鹤摄食栖息地面积的影响规律,可为通过三峡水库补水调度改善洞庭湖越冬水鸟摄食栖息地生境提供理论基础. 相似文献
16.
水生植物修复已经成为水体富营养化修复的重要手段,但其周期性的衰亡也给水体带来不容忽视的负效应.以府河流域丘陵地带农业区小水系自然生长的芦苇(Phragmites australis)和狭叶香蒲(Typha angustifolia)为研究对象,通过模拟实验,研究其冬季和春季腐烂分解过程的差异以及对水体营养盐水平的影响.结果表明,2种挺水植物的剩余干物质量整体上都呈现先快速下降再缓慢下降的趋势,芦苇和狭叶香蒲春季的分解速率分别为0.0251和0.0169 d~(-1),分别明显高于冬季分解速率(0.0027和0.0052 d~(-1));且腐烂分解速率与植物初始氮磷含量和氮磷比都有一定相关性.2种植物在冬季和春季磷的矿化速率都明显高于氮的矿化速率.实验水体的总氮和总磷浓度在腐解过程呈现初期迅速上升、中期迅速下降、后期缓慢下降的趋势.总体来看,芦苇和狭叶香蒲的腐烂分解受季节和初始氮磷浓度的影响较大,芦苇反应较香蒲更敏感且对水质的影响具有时效性. 相似文献
17.
Habitat-forming organisms are frequently used as biomonitors in marine environments due to a widespread ability to accumulate toxic contaminants. Few studies, however, have considered the consequences of these accumulated contaminants on the abundant and diverse fauna associated with these habitats. In this review, we summarize research which has investigated the contamination of biogenic habitats (including seagrasses, macroalgae, ascidians, sponges and bivalve reefs) and the impact of this contamination on the habitat use, feeding behaviour and survival of associated epifauna. In many cases, ecological impacts upon epifauna are not simply predicted by levels of contamination in their habitat, but are determined by the foraging, feeding and reproductive behaviours of the inhabiting organisms. Thus, a thorough understanding of these ecological processes is essential in order to understand the effects of contaminants upon epifaunal communities. The scope of biomonitoring studies which assess the contamination of biogenic habitats should be expanded to include an assessment of potential effects upon associated epifauna. When combined with manipulative field experiments such an approach would greatly assist in our understanding of indirect effects of contaminants in these important benthic habitats. 相似文献
18.
Shawn W. Hodges Daniel D. Magoulick 《Aquatic Sciences - Research Across Boundaries》2011,73(4):513-522
Drought and summer drying can be important disturbance events in many small streams leading to intermittent or isolated habitats.
We examined what habitats act as refuges for fishes during summer drying, hypothesizing that pools would act as refuge habitats.
We predicted that during drying fish would show directional movement into pools from riffle habitats, survival rates would
be greater in pools than in riffles, and fish abundance would increase in pool habitats. We examined movement, survival and
abundance of three minnow species, bigeye shiner (Notropis boops), highland stoneroller (Campostoma spadiceum) and creek chub (Semotilus atromaculatus), during seasonal stream drying in an Ozark stream using a closed robust multi-strata mark-recapture sampling. Population
parameters were estimated using plausible models within program MARK, where a priori models are ranked using Akaike’s Information
Criterion. Creek chub showed directional movement into pools and increased survival and abundance in pools during drying.
Highland stonerollers showed strong directional movement into pools and abundance increased in pools during drying, but survival
rates were not significantly greater in pools than riffles. Bigeye shiners showed high movement rates during drying, but the
movement was non-directional, and survival rates were greater in riffles than pools. Therefore, creek chub supported our hypothesis
and pools appear to act as refuge habitats for this species, whereas highland stonerollers partly supported the hypothesis
and bigeye shiners did not support the pool refuge hypothesis. Refuge habitats during drying are species dependent. An urgent
need exists to further understand refuge habitats in streams given projected changes in climate and continued alteration of
hydrological regimes. 相似文献
19.
苏北骆马湖大型底栖动物群落结构及水质评价 总被引：2，自引：1，他引：1
2014年1-12月,对苏北骆马湖水质和大型底栖动物进行了逐月调查.根据湖区的生境特征将骆马湖划分为3个区域:采砂区域、植被区域和其他区域.对比分析不同区域水质参数和底栖动物群落结构,并利用《地表水环境质量标准》(GB 3838-2002)、综合营养状态指数和生物学指数对水质进行评价.结果表明,采砂区域的水深显著高于植被区域,而透明度显著低于另外两个区域;采砂区域的总氮、总磷、硝态氮和正磷酸盐浓度均显著高于植被区域,生物多样性显著低于另外两个区域.骆马湖内共采集到大型底栖动物41种,其中环节动物8种,软体动物15种,节肢动物18种.铜锈环棱螺(Bellamya aeruginosa)、苏氏尾鳃蚓(Branchiura sowerbyi)、霍甫水丝蚓(Limnodrilus hoffmeisteri)、长角涵螺(Alocinma longicornis)是现阶段的优势种.10个监测点底栖动物的年均密度和年均生物量分别为77.19±43.59 ind./m~2和37.62±28.31 g/m~2,呈现出较高的空间异质性.生物量较密度空间差异更大,生物量在湖泊四周的监测点较高,而在湖心开阔水域较低.水质评价结果表明骆马湖水质处于中营养状态,总体属于中度污染,作为南水北调东线工程重要的调蓄湖泊以及饮用水源地和水产养殖基地,加强水环境保护不容懈怠. 相似文献
20.
为探究东南丘陵山区深水水库中生态浮床技术深度脱氮的效率及管理措施,以大型山谷型深水水库千岛湖为例,选取湿生植物空心菜(Ipomoea aquatica)和水生植物粉绿狐尾藻(Myriophyllum aquaticum),采用生态浮床技术,开展了原位模拟实验对比研究,探究不同营养盐浓度和光强下两种植物的生长状况与氮素去除效率。结果发现:(1)空心菜长势受营养盐和光照条件影响明显,添加氮磷后(TN=2.37 mg/L,TP=0.046 mg/L)的空心菜生物量是原位水体(TN=0.66 mg/L,TP=0.028 mg/L)的1.6倍,适当遮光有助于浮床植物生长,40%遮光条件下空心菜的生物量是不遮光条件下的1.5倍;而粉绿狐尾藻生长受营养盐和光照条件影响均较小。(2)空心菜对于水体氮素净化能力显著高于粉绿狐尾藻,在最佳条件下空心菜和粉绿狐尾藻对氮素的去除效率分别达到213.30和44.23 mg/(m2·d)。(3)空心菜去除氮主要以植物同化作用为主,占70%以上TN去除量,40%遮光环境通过明显提升空心菜同化吸收氮量和根系反硝化速率增强了氮的去除能力;粉绿狐尾藻同化吸收和反硝化脱氮作用各占50%左右,以遮光75%下脱氮效果最好。本研究表明,采用生态浮床技术能够强化深水水库的脱氮能力,空心菜更适合在氮浓度较高的水体生长,夏季为空心菜和粉绿狐尾藻浮床分别进行40%和75%的遮光处理将有更好的水质净化效果。因此,在滨岸湿地匮乏的深水水库实施多种植物搭配的生态浮床技术强化水体脱氮作用是一种行之有效的水质改善方法。 相似文献