应用鱼类完整性评价体系评价辽河流域健康

根据2009年8月辽河流域33个站点采集的鱼类数据(参照点8个,观测点25个),通过参数指标值分布范围、相关关系和判别能力分析,从23个侯选指标中筛选出了辽河流域的鱼类完整性指数(F-IBI)构成指标体系。该体系包括鱼类总种类数、Shannon-Wiener多样性指数、中上层鱼类百分比、底层鱼类百分比、鱼类个体总数、杂食性鱼类百分比、耐受性鱼类百分比、敏感性鱼类百分比和产粘性卵鱼类百分比共9个生物参数。分别采用1、3、5赋值法和比值法计算各站点的IBI分值,并根据参照点IBI分值的25%分位数值确定健康等级标准,对小于25%分位数值的分布范围进行3等分,提出了辽河流域河流鱼类完整性评价标准,分为健康、一般、差、较差4个等级。两种方法评价结果虽不完全相同,但趋势基本一致。Pearson相关分析表明IBI值与生境状况、水质状况、栖息地环境质量显著相关,其中与海拔、栖息地评分呈显著正相关,与CODCr、氯化物、总溶解颗粒物、含沙量、硬度、电导率呈显著负相关。     

Development issues in extending plant-based IBIs to forested wetlands in the Midwestern United States

Most plant-based indices of biotic integrity (IBIs) developed for wetlands have focused on emergent wetlands. A Vegetation Index of Biotic Integrity (VIBI-Forest) was developed for forested wetlands in the four large ecoregions of the Ohio. Assessing the effect of human disturbance on the ecological condition of wetland forests is complicated by several factors. First, forest canopies can remain largely intact even after significant degradation of the herb and shrub stratum. Second, increases in total diversity may not be good. In forested wetlands, a major artifact of disturbance is the addition of non-wetland or wetland native or adventive plant species adapted to full sun conditions to their floras. Initial versions of the VIBI-Forest metrics were very sensitive to disturbance-induced increases in diversity. Correcting this problem required modifying or replacing metrics so that only forest dependent species were included in metric calculations. The final VIBI-Forest included metrics which evaluated each forest stratum including the ground layer (% bryophyte), herb layer (shade or seed-less vascular plant species), shrub layer (subcanopy importance value (IV), relative density of young trees), canopy (canopy IV), and composite metrics for all vertical strata (Floristic Quality Assessment Index score, % hydrophytes, % sensitive, % tolerant). Assessing wetland forest condition is further complicated by the fact that some successional communities after canopy death or destruction (shrub swamp, marsh, wet meadow) may have intrinsic value as wetland community types. The solution is not to attempt to derive a one-size-fits-all assessment method but to derive separate protocols for other successional phases that are of value or interest.     

Applying an index of biotic integrity based on fish assemblages in a West African river

A multivariate measure of river quality, the Index of Biotic Integrity (IBI), was adapted to a West African river, the Konkoure (Republic of Guinea). Fish assemblages were sampled using gill-nets during the dry season to provide data for the IBI. Ten metrics were subsequently defined. The capacity of the modified IBI to assess the impact of a bauxite treatment plant was tested. The IBI decreased as expected at the impacted station. Detailed examination of the data revealed that one family, the Mormyridae, was almost eliminated from the impacted station, suggesting that members of this familiy can be considered as intolerant species in future uses of the IBI in other African rivers.     

河岸带生态系统退化机制及其恢复研究进展

恢复和重建自然和人为干扰导致的退化河岸带生态系统是目前恢复生态学、流域生态学等学科研究的重要内容之一．对河岸带生态系统的干扰表现在河流水文特征改变、河岸带直接干扰和流域尺度干扰3个方面,分别具有不同的影响机制．河流水文特征改变通过改变河岸土壤湿度、氧化还原电位、生物生存环境以及沉积物传输规律对河岸带生态系统产生影响;河岸带直接干扰通过人类活动及外来物种入侵而直接影响河岸带植被多样性;流域尺度干扰则主要表现在河道刷深、河道淤积、河岸带地下水位降低和河流冲刷过程改变等．河岸带生态恢复评价对象包括河岸带生态系统各要素,评价指标已从单一的生态指标转向综合性指标．河岸带生态恢复应在景观或者流域尺度上进行考虑,识别对其影响的生物和物理过程以及导致其退化的干扰因子,通过植被重建与水文调控来进行．扩展研究尺度和研究对象及采用多学科的研究方法将是今后相关研究中的重要问题．     

Cell wall integrity maintenance in plants: Lessons to be learned from yeast?

The plant cell wall is involved in different biological processes like cell morphogenesis and response to biotic/abiotic stress. Functional integrity of the wall is apparently being maintained during these processes by changing structure/composition and coordinating cell wall with cellular metabolism. In S.cerevisiae a well-characterized mechanism exists that is maintaining functional integrity of yeast the cell wall during similar processes. During the last years it has become obvious that plants have evolved a mechanism to monitor and maintain functional integrity of their cell walls. However, our understanding of the mechanism is rather limited. The available evidence suggests that similar signaling cascades may be involved and particular protein activities may be conserved between plants and yeast. Here we review the available evidence briefly and highlight similarities between yeast and plants that could help us to understand the mode of action of the signaling cascades maintaining plant cell wall integrity.     

A fish-based assessment tool for the ecological quality of the brackish Schelde estuary in Flanders (Belgium)

This paper presents a new approach which was developed to find an optimal combination of candidate metrics for creating a fish-based estuarine biotic index (EBI) for defining the quality status of an estuarine area. The key idea was that a powerful index should minimise two prediction errors simultaneously: falsely declaring the status of a site as disturbed while it is not (Type I error) and the reverse, falsely declaring a disturbed site as undisturbed (Type II error). The balance between both errors is an inherent characteristic of an index and can be displayed as a curve. The area under this curve (AUC) is a measure of the misclassification rate (smaller = better). This criterion was the basis for a stepwise approach whereby in each step a metric resulting in the highest reduction of AUC was added. Five metrics were selected and the distribution of their average was the basis to derive the thresholds for the classes of the EBI. This paper presents the fish-based index (EBI) for the brackish Schelde estuary in Flanders (Belgium). The index was calibrated against fyke net data from five sites during the period from 1995 to 2004. The sites ranged in quality from moderately impacted to very disturbed, classes 3 to 5 respectively. Despite there being neither of the highest classes 1 (high) and 2 (good), the EBI presented can serve as an evaluation tool in the highly impacted situation in Flanders as it discriminates well between moderate and highly impacted sites. In addition, its definition complies with the biological status classes of the European Water Framework Directive (WFD). Handling Editor: K. Martens     

Relative influence of variables at multiple spatial scales on stream macroinvertebrates in the Northern Lakes and Forest ecoregion, U.S.A.

• 1 We used 94 sites within the Northern Lakes and Forests ecoregion spanning Minnesota, Wisconsin and Michigan to identify environmental variables at the catchment, reach and riparian scales that influence stream macroinvertebrates. Redundancy analyses (RDA) found significantly influential variables within each scale and compared their relative importance in structuring macroinvertebrate assemblages.
• 2 Environmental variables included landcover, geology and groundwater delivery estimates at the catchment scale, water chemistry, channel morphology and stream habitat at the reach scale, and landcover influences at three distances perpendicular to the stream at the riparian scale. Macroinvertebrate responses were characterised with 22 assemblage attributes, and the relative abundance and presence/absence of 66 taxa.
• 3 Each scale defined macroinvertebrates along an erosional to depositional gradient. Wisconsin's macroinvertebrate index of biotic integrity, Ephemeroptera–Plecoptera–Trichoptera taxa and erosional taxa corresponded with forest streams, whereas organic pollution tolerant, Chironomidae and depositional taxa corresponded with wetland streams. Reach scale analyses defined the gradient similarly as dissolved oxygen and wide, shallow channels (erosional) opposed instream macrophytes and pool habitats (depositional). Riparian forests within 30 m of the stream coincided with an erosional assemblage and biotic integrity.
• 4 Next, we combined all significant environmental variables across scales to compare the relative influence of each spatial scale on macroinvertebrates. Partial RDA procedures described how much of the explained variance was attributable to each spatial scale and each interrelated scale combination.
• 5 Our results appeared consistent with the concept of hierarchical functioning of scale in which large‐scale variables restrict the potential for macroinvertebrate traits or taxa at smaller spatial scales. Catchment and reach variables were equally influential in defining assemblage attributes, whereas the reach scale was more influential in determining relative abundance and presence/absence.
• 6 Ultimately, comprehending the relative influence of catchment and reach scale properties in structuring stream biota will assist prioritising the scale at which to rehabilitate, manage and derive policies for stream ecosystem integrity.

     

What is the value of wild animal welfare for restoration ecology?

The restoration community continues to discuss what constitutes good environmental stewardship. One area of tension is the extent to which the well‐being of wild animals should inform restoration efforts. We discuss three ways that the perspective of wild animal welfare can augment restoration ecology: strengthening people's relationship with nature, reinforcing biotic integrity, and reducing mechanistic uncertainty. The animal welfare movement elevates sentient animals as stakeholders and explores how environmental context directly impacts the well‐being of individuals. Viewing wild animals through this lens may encourage people to think and act with empathy and altruism. Second, we incorporate animal welfare into the concept of biotic integrity for ecological and ethical reasons. Restoring ecosystem processes may enhance animal welfare, and vice versa. Alternatively, there may be a trade‐off between these factors, requiring local decision‐makers to prioritize between restoring ecosystem function and promoting individuals' well‐being. We conclude by discussing how welfare can impact population recovery, thereby adding insights about mechanisms underpinning restoration objectives. Ultimately, restoration ecologists and proponents of wild animal welfare could enjoy a productive union.     

基于浮游植物生物完整性指数的湖泊生态系统评价——以2012年冬季太湖为例

依据2012年12月对太湖29个样点和同一地理区划4个湖、库的浮游植物和环境变量的监测结果,应用生物完整性理论和方法,构建冬季太湖浮游植物生物完整性指数,评价冬季太湖水生态健康质量。采用干扰程度最小系统法定义筛选确定参照点,对51个候选参数进行分布范围筛选、判别能力分析、参数间相关性分析,获得了太湖枯水期P-IBI指数的6个构成参数:总分类单元数、硅藻门分类单元%、细胞Simpson指数、细胞密度、硅藻门细胞密度%和绿藻门个体密度%。采用比值法统一各参数的量纲,累加后得到枯水期太湖P-IBI分值,并划分健康评价标准。应用P-IBI对冬季太湖水生态进行评价,8个参照点中1个点位评价结果为健康其余7个为亚健康;25个受损点中,2个点位为亚健康,9个点位为一般,12个点位为差,2个点位为极差。太湖总体受到了不同程度的人为干扰,东太湖湖区水生态状况最好,评价结果多为亚健康或一般;竺山湖、贡湖、东部沿岸和西部沿岸次之;南部沿岸和湖心区最差,湖心区有2个点位评价结果为极差。与冬季太湖P-IBI指数显著相关的水化学因子是氨氮和总磷含量。     

Riverine invertebrate assemblages are degraded more by catchment urbanisation than by riparian deforestation

1. Restoration of riparian forests has been promoted as a means of mitigating urban impacts on stream ecosystems. However, conventional urban stormwater drainage may diminish the beneficial effect of riparian forests.
2. The relative effects of riparian deforestation and catchment urbanisation on stream ecosystems have rarely been discriminated because urban land use and riparian degradation usually covary. However, land use at three scales (channel canopy cover along a 100-m site, riparian forest cover within 200 m of the channel for 1 km upstream, and catchment imperviousness) covaried only weakly along the lowland Yarra River, Victoria, Australia.
3. We tested the extent to which each land use measure explained macroinvertebrate assemblage composition on woody debris and in the sediments of pools or runs in the mainstem Yarra River in autumn and spring 1998.
4. Assemblage composition in both habitats and in both seasons was most strongly correlated with proportion of catchment covered by impervious surfaces. Sites with higher imperviousness had fewer sensitive taxa (those having a strong positive influence on indicators of biological integrity) and more taxa typical of degraded urban streams. Sensitive taxa rarely occurred in sites with >4% total imperviousness. However, within sites of similar imperviousness, those with more riparian forest cover had more dipteran taxa. Channel canopy cover did not explain assemblage composition strongly.
5. Riparian forest cover may influence richness of some macroinvertebrate taxa, but catchment urbanisation probably has a stronger effect on sensitive taxa. In catchments with even a small amount of conventionally drained urban land, riparian revegetation is unlikely to have an effect on indicators of stream biological integrity. Reducing the impacts of catchment urbanisation through dispersed, low-impact drainage schemes is likely to be more effective.     

浙江西苕溪土地利用变化对溪流大型底栖无脊椎动物完整性的影响

土地利用/覆被变化对溪流生态系统的影响是溪流生态学研究的热点.生物完整性是诊断溪流生物学状况和生态健康的重要指标.目的是研究西苕溪流域内土地利用类型对大型底栖无脊椎动物完整性(B-IBI)的影响.利用2003年西苕溪TM数据和DEM模型计算了62个样点上游3种空间尺度下(亚流域、沿岸和局部)的土地利用类型.结果表明,耕地,民居和竹园在流域中的百分比与B-IBI负相关,耕地百分比对B-IBI的影响在亚流域(r=-0.527,p<0.001),河岸(r=-0.665, p<0.001)和局部(r=-0.696, p<0.001)尺度上均显著.针叶林,阔叶林和混交林百分比与B-IBI正相关.阔叶林百分比在亚流域(r=0.333,p<0.001),河岸(r=0.589 ,p<0.001)和局部尺度(r=0.618,p<0.001)与B-IBI显著相关.而针叶林百分比仅在亚流域尺度(r=0.366,p<0.001)与B-IBI显著相关.在研究流域内耕地百分比小于50%的情况下,B-IBI并非随着耕地百分比的增长而线性下降,而是在达到一定阀值后(亚流域尺度,27%;河岸尺度,57%;局部尺度,59%)耕地的影响逐渐趋缓.在耕地百分比小于阀值前,B-IBI在局部尺度上与耕地百分比的增长的关系最强(r=-0.808, p<0.001, n=46).建议在沿岸区增加阔叶林,针叶林与混交林的占有率,或者建立耕地与溪流间的林地缓冲带,有助于保护和恢复西苕溪生态健康.     

挠力河流域河流的B-IBI评价

挠力河流域是中国东北三江平原地区重要的商品粮基地之一.选择挠力河流域干支流6个河段21个样点,2007年7月进行河流大型无脊椎动物样本的采集和鉴定,并分别采用3分法和比值法进行了河流大型无脊椎动物完整性指数(简称B-IBI)计算与评价.结果显示,使用两种方法得出的评价结果基本一致,且与水质、生境质量评价结果呈显著正相关关系.研究表明,挠力河流域河流生物完整性总体良好,个别样点较差.全流域属于无干扰和轻度干扰的样点占71.4%,中度干扰的样点占23.8%,重度干扰的仅占4.8%.得分较高的样点多处于挠力河支流或干流上游的山区,人类活动较少,河流周围为茂密的森林植被;分值较低的样点主要位于支流下游或干流中游,均临近居民点,水体质量较差,河岸人类活动密集,植被覆盖度低,土地开发利用强烈等特征.这表明,河流B-IBI受到河岸土地覆被和土地利用(LULC)的重要影响.