转野生荠菜凝集素基因棉花对赤子爱胜蚓的影响

在实验室条件下分别给赤子爱胜蚓(Eisenia foetida)饲喂在自然状况下可能接受的棉叶最高添加量和2倍最高添加量的转野生荠菜凝集素(WSA)基因棉花(Gossypium hirsutum)叶片,并以其亲本棉花叶片为对照,以牛粪为阴性对照,以农药为阳性对照,研究种植转WSA基因棉花对赤子爱胜蚓死亡率、生长及繁殖的影响。结果表明,在49 d的试验周期内,与取食亲本棉花叶片的赤子爱胜蚓相比,取食转WSA基因棉花叶片的赤子爱胜蚓的死亡率,体质量,GST、SOD、纤维素酶活性以及蚓茧数和小蚯蚓数均无显著差异,未发现转WSA基因棉花对赤子爱胜蚓有不利影响。     

全氟辛烷磺酸盐(PFOS)替代品对中国白羽鹌鹑的生态毒性

为研究全氟辛烷磺酸盐(perfluorooctane sulfonate,PFOS)替代品对环境生物的毒害效应,选用中国白羽鹌鹑作为受试生物,建立其环境危害评价毒性测试方法,并对PFOS替代化学品进行了急性经口、急性饲喂及繁殖毒性的风险评价。结果表明,全氟丁基有机铵盐阳离子表面活性剂急性经口毒性实验的LD50为500.44mg·kg-1,其余3种替代化学品在上限浓度2000mg·kg-1,白羽鹌鹑均未出现明显死亡,4种PFOS替代品对中国白羽鹌鹑的急性经口毒性均为低毒。全氟丁基有机铵盐阳离子表面活性剂急性饲喂毒性实验的LC50为970.50mg.kg-1,对白羽鹌鹑的饲喂毒性为中毒,而其余3种替代化学品在上限浓度5000mg·kg-1,白羽鹌鹑均未出现明显死亡,对中国白羽鹌鹑的急性饲喂毒性为低毒。在长期饲喂过程中,织物三防整理剂和C6织物三防整理剂会表现出一定的生殖毒性,造成中国白羽鹌鹑的孵化率降低,胚胎死亡率及未受精率升高;全氟丁基有机铵盐阳离子表面活性剂会影响到中国白羽鹌鹑的未受精率,C4织物三防整理剂未表现出明显的生殖毒性。     

模拟增温效应对西藏苔草繁殖生态的影响

通过采用国际冻原计划模拟增温对植物影响的方法,从繁殖生态学角度研究了西藏苔草（Carex thibetica Franch）种群的物候期、分蘖数、生物量和种群繁殖对增温的响应。结果表明：暖棚内气温、土壤表层温度分别了1.17℃和1.50℃;物候期提前或延迟,生长期延长;增温可以提高西藏苔草的生殖产量,但不提高其种子发芽率;增温可提高西藏苔草分蘖数和生物量;西藏苔草繁殖对策趋于营养繁殖。     

多点汇流下污水管网污染物迁变规律及其机制

为研究城市污水管网多点汇流条件下污染物的迁变规律及其对微生物繁衍的影响机制,建立一套多汇流点位的污水管道中试系统,探究污水输送过程中碳,氮,硫3类主要污染物质的迁移转化特性.结果表明,汇流点前溶解态化学需氧量（SCOD）和硫酸盐（SO₄^2-）浓度下降,氨氮（NH₄⁺-N）浓度上升,支管汇流使得汇流点3类污染物浓度显著增加.后期水质达到稳定,在保证支管污水的汇入导致各类污染物增加量基本不变的情况下,SCOD浓度由进口的320mg/L左右下降至出口的280mg/L左右,在氨化作用下导致的NH₄⁺-N总增加量在15mg/L左右,高于因汇流产生的增加总量12.5mg/L左右,结果表明汇流管网系统中微生物的消耗代谢作用是碳氮类污染物变化的主导因素,而SO₄^2-后期进出口浓度均在20mg/L左右,说明支管汇流和生化代谢使SO₄^2-的含量维持在动态平衡的状态.此外,对管网中试系统生物相中微生物繁衍过程进行分析可知,发酵菌（FB）,产氢产乙酸菌（HPA）,硫酸盐还原菌（SRB）的含量随繁衍时间显著增加,并在沿程的不同汇流点处出现丰度升高现象.综上所述,在多点汇流导致污水水质波动的作用下,促进了管网生物相中微生物的繁衍增殖,并增强了其代谢作用在污水管网污染物转化的主导地位,使得污染物在管网输送过程中呈现更为显著的转化现象.     

Evaluating unintended consequences of intentional species introductions and eradications for improved conservation management

Increasingly intensive strategies to maintain biodiversity and ecosystem function are being deployed in response to global anthropogenic threats, including intentionally introducing and eradicating species via assisted migration, rewilding, biological control, invasive species eradications, and gene drives. These actions are highly contentious because of their potential for unintended consequences. We conducted a global literature review of these conservation actions to quantify how often unintended outcomes occur and to elucidate their underlying causes. To evaluate conservation outcomes, we developed a community assessment framework for systematically mapping the range of possible interaction types for 111 case studies. Applying this tool, we quantified the number of interaction types considered in each study and documented the nature and strength of intended and unintended outcomes. Intended outcomes were reported in 51% of cases, a combination of intended outcomes and unintended outcomes in 26%, and strictly unintended outcomes in 10%. Hence, unintended outcomes were reported in 36% of all cases evaluated. In evaluating overall conservations outcomes (weighing intended vs. unintended effects), some unintended effects were fairly innocuous relative to the conservation objective, whereas others resulted in serious unintended consequences in recipient communities. Studies that assessed a greater number of community interactions with the target species reported unintended outcomes more often, suggesting that unintended consequences may be underreported due to insufficient vetting. Most reported unintended outcomes arose from direct effects (68%) or simple density-mediated or indirect effects (25%) linked to the target species. Only a few documented cases arose from more complex interaction pathways (7%). Therefore, most unintended outcomes involved simple interactions that could be predicted and mitigated through more formal vetting. Our community assessment framework provides a tool for screening future conservation actions by mapping the recipient community interaction web to identify and mitigate unintended outcomes from intentional species introductions and eradications for conservation.     

Diversity of Ontogenetic Pathways in Plant Populations

Population heterogeneity in cespitose, fibrous-rooted, brevirhizomatous, stoloniferous, and tap-rooted herbaceous and woody plants is described. This heterogeneity is caused by the multivariant character of plant ontogeny (i.e., its dimensional, morphological, rhythmological, and temporal multiversality), which is regarded as the main adaptation mechanism operating in plant populations because it provides for the diversity of ontogenetic pathways under different ecological conditions.     

重金属铅、镉对矮小拟丽突线虫（Acrobeloides nanus）的亚急性毒性作用

为了探讨重金属Pb、Cd对矮小拟丽突线虫(Acrobeloides nanus)的亚急性毒性作用,采用室内培养的方法,研究了不同浓度Pb和Cd对矮小拟丽突线虫生长发育、繁殖的影响,并对线虫世代间的毒性效应进行了比较.结果表明,1)与对照组相比,各暴露组当代(P0)和后代(F1)线虫平均体长均显著降低(p<0.05,p<0.01);随着重金属浓度的增加,当代(P0)和后代(F1)线虫平均体长呈现逐渐降低的趋势.2)随着Pb、Cd暴露浓度的增加,线虫产卵数逐渐降低;Pb对线虫产卵数的72h-EC20、EC10分别为17.41、4.36mg·L-1,Cd对线虫产卵数的72h-EC50、EC20和EC10分别为4.47、0.91和0.53mg·L-1.以上结果表明,重金属Pb、Cd暴露可显著抑制矮小拟丽突线虫的生长发育、繁殖;线虫体长、产卵数具有明显的重金属浓度依赖性。     

九寨沟自然保护区4种水深梯度下芦苇分株地上生物量的分配与生长

芦苇是世界自然遗产--九寨沟自然保护区的一种重要的湿地植物.本文对该地区芦苇海4个不同水深梯度下芦苇的无性系地上分株的生物量分配、生长与繁殖策略进行了比较研究.结果表明,在47 cm (水在土层表面上)水深环境中,芦苇单株的平均生物量(4.2 g)最大.在-15 cm (水在土层表面下15 cm)的生境中,叶生物量百分比(叶生物量占单株总生物量的百分比, 46.1%)最大.芦苇地上分株高度、地上分株有分枝的单株百分比(茎上有分枝的分株占样地总分株的百分数)也存在明显的差别.茎的生物量分配百分比和生长速率随水深的增加而增加.在滩地生境中,开花率、花序的生物量百分比明显大于水较深的生境.分株株高与分株生物量、茎生物量与叶生物量都表现出较明显的幂指数异速生长规律.在-15 cm水深的生境中,叶生物量的生长快于茎的增长;在其他水深梯度的生境中,则是茎生物量的增加快于叶生物量的增加.     

电助光催化氧化苯甲酰胺

以钛板为基材,采用溶胶-凝胶法制备固定膜 TiO₂/Ti 光催化剂,并对其施加一定的阳极偏电压,对苯甲酰胺溶液进行了电助光催化氧化处理.考察了阳极偏电压、溶液浓度和pH值对苯甲酰胺降解效率和光电流的影响规律,并比较了电助光催化氧化与光催化氧化、光解和电解处理对苯甲酰胺去除率的差异.结果表明,外加阳极偏电压可以大大提高光催化氧化技术的处理效率,最佳工艺条件为偏电压+0.6V/SCE,苯甲酰胺溶液的浓度 1.0mg/L,溶液呈酸性.在此条件下,经过 1h的处理,苯甲酰胺的去除率可达 90%.     

Ecological effects of cultivation on the machair sand dune systems of the Outer Hebrides, Scotland

The machair sand dune systems of the Outer Hebrides of Scotland are a unique habitat, which is rare within both a global and European context. Unusually, the machair habitat also represents an agricultural resource that is very important to the Hebridean people, having been subject to both grazing and cultivation throughout the historical period. Following designation as an Environmentally Sensitive Area (ESA) in 1988, the machairs of South Uist have been studied with the aim of understanding the links between agricultural practice and their plant community and ecosystem dynamics. This research focused primarily on the effects of cultivation practices and their role in maintaining plant species richness and community and ecosystem stability. Within two carefully selected areas, the successional plant communities of machair at different stages of recovery following ploughing and cultivation of cereals and potato patches or ‘lazy beds’ were identified at both a macro- and micro-level. Investigations of the vegetation recovery processes on turves taken from newly ploughed land indicated that the initial stages of recolonization are characterized primarily by rapid vegetative reproduction and growth, although re-vegetation by seeds is also an important factor. The implications of these findings for the long-term management of machair plant communities are discussed and in particular the need to maintain old cultivation practices such as shallow ploughing. The need for more detailed research into both seed banks and seed rain and into processes of vegetative reproduction is stressed. Nomenclature: Clapham et al. (1981) and Stace (1991, 1997) for vascular plants; Hubbard (1984) for grasses; Pankhurst & Mullin (1991) for the regional flora; Dobson (1992) for lichens; Watson (1981) for mosses and liverworts.