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附着生物对太湖常见的两种沉水植物快速光曲线的影响 总被引：5，自引：2，他引：3
在水草生长比较旺盛的季节(7-8月),以水草较丰富的贡湖湾作为采样区域,野外采样结合室内分析研究太湖常见的两种沉水植物马来眼子菜(Potamogeton malaianus)及穗花狐尾藻(Myriophyllum spicatum)叶上的附着生物的生物量;利用脉冲振幅调制叶绿素荧光仪研究去除附着生物前后两种沉水植物的光合作用的变化.结果表明,马来眼子菜和穗花狐尾藻两种沉水植物上的附着生物的现存量存在显著的差异,附着生物群落中自养生物与异养生物的比值没有显著差异;两种沉水植物在去除附着生物前后的光合参数有显著的变化,光合作用效率、半饱和光强、最大电子传递速率增加.这表明附着生物降低了沉水植物光合作用. 相似文献
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Abstract. On the subtidal rocky shore of Akkeshi Bay, Hokkaido, Japan, the congeneric phytal gastropods, Lacuna uchidai and L. decorata , inhabit the multispecific vegetation consisting of the surfgrass, Phyllospadix iwatensis and the brown alga, Cystoseira hakodatensis . We studied the phenologies of Phyllospadix and Cystoseira , host utilization patterns and life histories of Lacuna spp. to examine how these gastropods accommodate the seasonal fluctuations of the habitat. The preferences for macrophyte by Lacuna spp. were examined by laboratory experiments. The phenologies of macrophytes, the seasonal and between-substrata variations of Lacuna spp. were examined by monthly sampling from Phyllospadix and Cystoseira beds between May 1999 and May 2000. Lacuna uchidai showed significant preference for Phyllospadix , whereas L. decorata had no preference for a particular substratum. Most L. uchidai were collected from the Phyllospadix bed, however L. decorata appeared in both Phyllospadix and Cystoseira beds. The peak of new recruit of L. uchidai coincided with that of Phyllospadix biomass. The synchronization of life cycle with the phenology of the host may be adaptive for using the limited habitat. Seasonal variation in density of L. decorata coincided with neither patterns for Phyllospadix nor Cystoseira . Seasonal variation in density and size frequency distribution suggested L. decorata migrated among adjacent macrophytes. Although it was a little vague, this hypothesis was probably the best explanation of our results. Our study shows that two co-occurring Lacuna species utilize the macrophytes as habitats by the different life histories and utilization patterns and, may be alternatively accommodated to the seasonal fluctuations of their habitats. 相似文献
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Temporal and bathymetric variation of epiphyte cover and leaf biomass in a southern Posidonia oceanica (L.) meadow: the case of Mahdia coast,Tunisia 
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下载免费PDF全文 The aim of this research was to study spatial and temporal variation in epiphyte cover and leaf biomass of Posidonia oceanica in Eastern Tunisia. Sampling was conducted at four stations on the Mahdia coast during October and December 2010, and April and August 2011, which correspond respectively to autumn, winter, spring and summer in this area. Posidonia oceanica shoots were collected at two depths (5 and 10 m). Cover of macroinvertebrates and macroalgae was estimated on adult leaves. The results showed that leaf and epiphyte biomasses vary significantly according to sampling date, with the highest values recorded in August. We found a high diversity of epiphytic assemblages on the leaves of P. oceanica with clear qualitative and quantitative dominance of Rhodophyceae compared to other groups, followed by Phaeophyceae. Most epiphyte species on the leaves of P. oceanica in Eastern Tunisia are the same as those in other parts of the Mediterranean Sea. No bathymetrical variation in the epiphytic community was found in our study area, which can be explained by the high levels of water clarity in Mahdia. 相似文献
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攀西地区生物资源开发与生物农药发展 总被引：1，自引：0，他引：1
分析了攀西地区独特的自然条件,丰富的生物资源,指出攀西地区是生物农药原料的“宝库”。通过对国内外的生物农药发展现状的介绍,分析了目前国内生物农药市场,发现其具有广阔的发展空间。阐述了攀西特色生物资源开发中印楝和真菌农药的开发研究进展。论述了发展攀西生物农药可改善当地的生态环境,并可形成长江上游生态环境屏障,促进攀西生态产业的形成。得出了攀西具有良好的生物农药发展潜力和广阔前景的结论。 相似文献
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海草场的生态功能 总被引：5，自引：0，他引：5
海草场作为特殊的海洋生态系统之一,尽管其面积占海洋总面积的比例很小,但其具有极高的初级生产力,在地球系统碳循环中起着不可忽视的作用。海草本身还可以作为其他附着生物的附着基,进一步提高了海草场的初级生产力,并为许多海洋动物提供了适宜的食物。海草场的存在,改变了海草场内的流体动力过程,加速了悬浮颗粒的沉降,对稳定海底底质和净化水质有着积极的作用,因此被称为"生态系统工程师"。海草本身可以作为一些海洋动物的食物,同时其复杂的地下和地上结构还为一些海洋动物提供了庇护和栖息场所。而海草植物体的大部分,将最终被微生物分解利用,所产生的营养盐可以满足其它初级生产者生长所需。本文通过总结世界范围内海草场生态学研究成果,旨在阐述海草场生态系统的特征及功能,以提高人们对海草场生态功能的认识,唤起人们对海草场的重视与保护意识。 相似文献
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Epifaunal invertebrate species, such as amphipods and isopods, have been shown to play key but varying roles in the functioning of seagrass habitats. In this study, we characterized patterns in the poorly known epifaunal communities in eelgrass (Zostera marina) beds in San Francisco Bay as a first step in understanding the individual and collective importance of these species, while testing predictions on spatial patterns derived from previous studies in other regions. Surveys conducted at five beds across multiple time periods (April, June, August and October 2007) showed that San Francisco Bay eelgrass beds varied strongly in epifaunal community composition, total, and relative abundance, and that abundance differed markedly among time periods. In contrast to findings by others, morphologically complex flowering shoots frequently harbored greater numbers of epifauna (>2× and up to 10× more individuals) than vegetative shoots, but not different species assemblages. Similar to previous studies, several abiotic factors did not explain patterns in distribution and abundance among beds. The proportion of introduced species was very high (>90% of all individuals), a finding unique among seagrass epifaunal studies to date. Defining numerical patterns in epifaunal communities will inform related efforts to understand effects of epifaunal species and assemblages on eelgrass growth dynamics, seed production, and higher order trophic interactions over space and time. 相似文献
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在云南哀牢山西麓川河河谷残存有较大面积的季风常绿阔叶林,其周围分布着思茅松林.采用典型取样法,对季风常绿阔叶林及思茅松林的物种组成与群落结构进行了调查和分析,结果表明:季风常绿阔叶林乔木层的优势种主要是红木荷(Schima wallichii)、高山栲(Castanopsis delavayi)、密花树(Rapanea neriifolia),而思茅松成熟林以思茅松(Pinus kesiya var.langbianensis)为绝对优势.在季风常绿阔叶林的29株样树树干上共调查到附生植物共36种,但在思茅松林中几乎找不到附生植物.季风常绿阔叶林和思茅松成熟林的香农-威纳多样性指数分别为3.32和1.70;相对于思茅松林,季风常绿阔叶林物种组成和群落结构都更复杂,具有较高的生物多样性和稳定性.由于该区域的季风常绿阔叶林受到了较为严重的人为干扰和破坏,因此,需要进一步加强对山地森林植被的保护与管理,尽量减少人为干扰,并采取适当的人工抚育措施,促进该区山地森林资源的保护和恢复. 相似文献
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贵州香纸沟岩溶藓类附生水生原生动物群落生态特征 总被引：1，自引：0，他引：1
岩溶藓类是一种独特的生态系统类型,维持了丰富的附生水生原生动物群落多样性。2006年11月26日至2007年1月26日, 对贵阳市香纸沟岩溶沉积环境中8种藓类附生水生原生动物群落进行了野外生态调查,采集样品和标本48份。经室内对附生水生原生动物培养、分离和鉴定, 揭示了该区岩溶藓类附生水生原生动物群落具有下述特征: ( 1)水生原生动物群落物种组成含24科26属36种。( 2)水生原生动物群落含6个功能营养群。其中,原生动物光合营养群( P群, Photosy nthetic auto tro phs) , 占总数的25% ; 细菌取食者群( B群, Bactivores detritivores) , 占总数的44. 44% ; 腐生营养类群( S群, Saprotrophs) ,占总数的2. 78% ;食藻者类群( A群, Algivores) ,占总数的11. 11% ; 非选择性杂食者群( N 群,Nonselective omnivores) , 占总数的11. 11% ;食肉者群( R群, Raptor s) ,占总数的5. 56%。( 3)根据岩溶水流、基质和藓类植物特征,划分该区附生水生原生动物生态群落为4个类型和8个亚类型。 相似文献
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We conducted a field experiment to assess the response of phytal harpacticoids to nutrient‐driven increases of epiphyte load in Posidonia oceanica meadows. First, we evaluated differences in species richness, diversity and assemblage structure of phytal harpacticoids in P. oceanica meadows with differing epiphyte loads. Secondly, we conducted a field experiment where epiphyte load was increased through an in situ addition of nutrients to the water column and evaluated the responses of the harpacticoid assemblages. We predicted that there would be changes in the harpacticoid assemblages as a result of nutrient‐driven increases of epiphyte load, and that these changes would be of a larger magnitude in meadows of low epiphyte load. Our results show that the harpacticoid fauna (>500 μm) present in P. oceanica meadows in the Bay of Palma comprised taxa which are considered phytal and other less abundant ones previously described as sediment dwellers or commensal on other invertebrate species. Nutrient addition had an overall significant effect on epiphyte biomass and on harpacticoid abundance, diversity and assemblage structure, possibly as a response to the increased resources and habitat complexity provided by epiphytes. The abundance of dominant species at each location was favoured by nutrient addition and in some cases correlated with epiphytic biomass, although never strongly. This may indicate that structural complexity or diversity of the epiphytic cover might be more important than the actual epiphytic biomass for the harpacticoid species investigated. More species‐specific studies are necessary to ascertain this and clarify the relationships between harpacticoids and epiphytes in seagrass meadows. To our knowledge, this is the first account of harpacticoid species associated with P. oceanica leaves and the epiphytic community they harbour in the Mediterranean Sea. 相似文献
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