Integrating Nonindigenous Aquatic Plant Control with Protection of Snail Kite Nests in Florida

The endangered snail kite (Rostrhamus sociabilis) feeds primarily on the freshwater apple snail (Pomacea paludosa) in Florida. The nonindigenous, floating water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) impede kites from finding snails. Effective control of these aquatic plants in the littoral zone of central and south Florida lakes benefits kites by maintaining open foraging habitat. However, incidental herbicide spraying of nesting substrates result in nest collapse when kites breed in nonwoody, emergent plants [cattail (Typha spp.) and giant bulrush (Scirpus validus)] in the outer littoral zone during lower lake levels. Many endangered species recovery plans and their implementation have experienced problems due to inaction and/or noncooperation by various governmental agencies and their personnel. Herein, we describe the development and implementation of a buffer zone strategy to prevent secondary impacts from an aquatic plant control program to snail kites nesting on lakes in central and south Florida. A strategy was jointly developed by personnel of five state and federal agencies to control herbicide application near kite nesting areas during the normal breeding season. Although requiring various modifications during its implementation, this cooperative effort successfully integrated aquatic plant control objectives with snail kite conservation on Lake Okeechobee during 1988. The program was expanded the following year to lakes Kissimmee and Tohopekaliga. Since the implementation of the snail kite impact preclusion program, no nest loss was attributed to incidental herbicide applications on lakes Okeechobee, Kissimmee, and Tohopekaliga.     

An experimental study of soil conservation using herbaceous plants in Majuli Island, Assam, India

A model experiment on soil conservation utilising the plantation of certain herbaceous plants in a selected stretch of Majuli, the largest riverine island in the world, was carried out. The plantation followed work to establish the proper inclination for the river bank. The soil erosion in the experimental site was reduced to only about 2% compared with about 15–20% in the previous years. All the four species selected for the present study had excellent soil binding capacity and were thus helpful in stabilizing the highly vulnerable soil in the flood plain areas of the region.     

完达山地区药用植物资源调查与开发利用

通过对完达山地区进行长期调查发展,该地区共有药用植物资源80科224种,并以植物分类学进行了统计,提出了合理开发利用药用植物的建议,为研究和合理利用完达山地区药用植物资源提供了基础材料。     

投放底栖动物强化水耕植物过滤法的净水效果

在水耕植物过滤法净水系统中的植物栽培廊道中,通过投放2种底栖动物螺蛳和泥鳅延长食物链后,TN、TP、TOC、Chl.a的去除效果均比未投放底栖动物的廊道有所提高.投放螺蛳的效果最为显著,TN、TP、Chl.a的去除率增幅分别达54%、27%和26%,比较了不同廊道中底泥的硝化、反硝化潜力,投放螺蛳的廊道其反硝化潜力最大,为9.08×10^-7g/(g·h),而硝化潜力最小,为3.65×10^-6g/(g·h).除氮能力大幅增加的原因,是由于螺蛳的引入增加了物质在食物链营养级传递中的损耗,另一方面是由于螺蛳的存在提高了底泥的反硝化潜力.     

Abundance and diversity of the phyllosphere bacterial communities of Mediterranean perennial plants that differ in leaf chemistry

Summary.  We studied the epiphytic bacterial communities of the summer leaves of eight perennial species naturally occurring in a Mediterranean ecosystem. The species differ in essential-oil content (from rich in essential oil to non-producers) and composition, and also in life form (from herbaceous species to tall shrubs). We compared the epiphytic bacterial communities on the basis of (i) their abundance, (ii) their metabolic profile (derived by use of the BIOLOG Ecoplate system) and (iii) richness and diversity of substrates that they use, as a measure of functional diversity. Among all species, the aromatic Melissa officinalis was the most abundantly colonized. The bacterial communities on the leaves of the aromatic Myrtus communis, Calamintha nepeta and Melissa officinalis, and also of Cistus incanus catabolized all 31 substrates offered; those on the evergreen-sclerophyllous species, Arbutus unedo and Quercus coccifera, catabolized only 14 and 17 substrates, respectively. Carbohydrates were consistently used abundantly by all communities, whereas carboxylic acids were most variably used. On average, the group of aromatic plants scored higher regarding bacterial abundance, and richness and diversity of substrates used by the bacterial communities on their leaves; the lowest values for both substrate-use indices were recorded in A. unedo. Bacterial abundance or richness or diversity of substrates used did not vary with leaf oil content. Abundance was positively correlated with both substrate-use indices. Results support claims that the antimicrobial effects of essential oils are not exerted so much under natural conditions as reports based on biassays with pathogens usually show. Although essential oils play a part in the microbial colonization of the phyllosphere, it is not likely that inhibition of phyllosphere bacteria is essential oils’ primary role, at least in the Mediterranean environment.     

Ecologically neglected tannins and their biologically relevant activity: chemical structures of plant ellagitannins reveal their in vitro oxidative activity at high pH

Summary.  Chemical structures of 27 ellagitannins were systemically compared in respect of their in vitro oxidative activity at high pH found e.g. in lepidopteran insects. The analysis revealed over six-fold differences in the oxidative activities of individual ellagitannins which could be explained by the chemical divergences of the ellagitannins. These findings allowed the formulation of a simple equation that can be used to estimate the oxidative activities of other ellagitannins with known structures. The results suggest that, in future studies of plant-herbivore interactions, ellagitannins should be (1) taken into account as possible oxidative stress -based defences of plants against herbivores, (2) chemically characterized from the study plants, and (3) quantified individually, not as chemically ill-defined group. These actions together with the utilization of the created equation would allow the clarification of the role of ellagitannins in plant-herbivore interactions as natural pro-oxidants.     

鄱阳湖湿地重金属形态分布及植物富集研究

研究了鄱阳湖湿地土壤中Cu,Zn,Pb和Cd形态与植物富集的关系. 结果表明:鄱阳湖土壤中Cu,Pb和Zn主要以有机态和残渣态为主,水溶态和离子交换态等生物有效性态含量很少;而Cd则主要以水溶态和离子交换态等生物有效性态为主,因此Cd的生态危害较大. 相关分析和偏相关分析均显示:植物中重金属含量与其生存环境中重金属水溶态或离子交换态含量直接相关,这与理论上植物只能吸收重金属水溶态相符. 植物对重金属的富集能力表现出Zn＞Cu＞Cd＞Pb的趋势. 用重金属水溶态或离子交换态进行植物富集研究,更具有可比性和科学性.      

生物滴滤器处理味精厂挥发性恶臭废气的试验研究

报道了采用以沸石为填料的生物滴滤器净化处理味精厂内挥发性恶臭废气的试验结果。在一定的试验条件下,当高强度恶臭废气的进气量<3.0m3/h时,系统除臭效果显著,这为净化以味精厂内恶臭废气为代表的多组分复杂气体提供了切实可行的新技术,具有很好的市场应用前景。此外,研究表明,在净化氨氮臭气取得良好效果的生物膜基础之上,加入特定菌液能较快地培养出适宜处理味精厂内恶臭废气的微生物种群,且能获得满意的净化效果。     

The use of physiological characteristics for comparison of organic compounds phytotoxicity

The influence of intact (FLT) and photomodified (phFLT) fluoranthene (0.05, 0.5 and 5 μmol l⁻¹) and herbicide Basagran (5, 20, 35 and 50 nmol l⁻¹) on the germination, growth of seedlings and photosynthetic processes in pea plants (Pisum sativum L., cv. Garde) was investigated. The germination was significantly inhibited already by the lowest concentration (0.05 μmol l⁻¹) of FLT and phFLT, while Basagran caused inhibition only in higher concentrations (35 and 50 nmol l⁻¹). The growth of roots was significantly inhibited by higher concentration 5 μmol l⁻¹ of both FLT and phFLT and the shoot of seedlings was significantly influenced only by photomodified form. The length of root and shoot was inhibited already by concentration 5 nmol l⁻¹ of Basagran. Organic compounds applied on chloroplasts suspension influenced primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F₀ values and the decrease of F_V/F_M and Φ_II values by application of FLT (0.5 and 5 μmol l⁻¹) and phFLT (0.05, 0.5 and 5 μmol l⁻¹) was recorded. The maximum capacity of PSII (F_V/F_M) was influenced by the highest (50 nmol l⁻¹) and the effective quantum yield of PSII (Φ_II) already by the lowest (5 nmol l⁻¹) concentration of Basagran. Hill reaction activity decreased and was significantly inhibited by higher concentration (0.5 and 5 μmol l⁻¹) of FLT and phFLT and already by the lowest concentration (5 nmol l⁻¹) of Basagran.