湛江高桥红树林湿地底栖动物粒径谱

在我国,红树林湿地底栖动物粒径谱研究很少。根据2010年1月、4月、7月、10月在湛江高桥红树林湿地获得的大型和小型底栖动物数据,构建了底栖动物生物量粒径谱,以期为湛江高桥红树林湿地的生态保护和持续利用提供科学依据。主要研究结果如下:(1)高桥红树林湿地生物量粒径谱基本为3峰模式。第一峰在-2粒级,主要由线虫构成;第二峰在4—12粒级,主要由寡毛类、多毛类和小个体甲壳类构成;第三峰在13—22粒级,主要由大个体腹足类、双壳类和甲壳类构成。(2)木榄、桐花树和无瓣海桑生境在0—4粒级之间出现一个明显的波谷,这个波谷介于线虫和寡毛类之间,是大型与小型底栖动物粒级交汇区。(3)高桥红树林湿地底栖动物正态化生物量粒径谱的斜率大于-1,截距为16.533—18.150。桐花树(Aegiceras corniculatum)和无瓣海桑(Sonneratia apetala)生境的截距、最小粒级的生物量(BMS)高于木榄(Bruguiera gymnorrhiza)和盐地鼠尾粟(Sporobolus virginicus)生境,说明桐花树和无瓣海桑生境的底栖动物生产力水平较木榄和盐地鼠尾粟生境的高;秋季的截距、BMS较其他季节高,说明秋季的底栖动物生产力水平较其他季节高。

Size spectrum of benthic fauna in Zhanjiang Gaoqiao Mangrove Wetlands, China

The biomass size spectrum (BSS) theory was introduced by Sheldon et al. in 1972 to describe the features of marine pelagic ecosystems. Schwinghamer was the first to extend this concept to benthic assemblages. Traditionally, benthic communities are described by structural variables, such as abundance, species composition, and biodiversity indices. Analysis of the distribution of biomass by size is an ataxonomic approach to studying the structures and functions of the benthic communities. The introduction of the BSS theory provides a new method for benthic ecology research. Compared to taxonomic approaches for studying the structures and functions of benthic communities, the BSS theory is easier to operate, in which calculation errors caused by inaccurate taxonomic identification may be avoided. Because of the urgent need to understand the structures and functions of marine ecosystems, and to accurately detect the ecological systems, the fields of application for the BSS theory will become more extensive. In China, most studies on the size spectrum of zoobenthos have been conducted in the subtidal zone, with only a few studies having been conducted in the intertidal zone. In addition, no studies have been conducted in mangrove swamps. To provide a scientific basis for the ecological protection and sustainable use of the Gaoqiao Mangrove Wetlands, the BSS of the benthic fauna in this area was constructed from macrofaunal and meiofaunal samples collected in January, April, July, and October 2010. The main results showed that the BSS of the benthic fauna in Gaoqiao Mangrove Wetlands exhibits 3 peaks. The first peak appeared at a grain size of -2, and comprised nematodes. The second peak appeared at grain sizes of 4-12, and comprised oligochaetes, polychaetes, and small-bodied crustaceans. The third peak appeared at grain sizes of 13-22, and comprised large-bodied gastropods, bivalves, and crustaceans. For Aegiceras corniculatum, Sonneratia apetala and Bruguiera gymnorrhiza biotopes, there was a trough at grain sizes 0-4, which was the intersection grain size between macrofauna and meiofauna. The slope values of the normalized biomass size spectra (NBSS) were greater than -1, while the intercepts ranged from 16.533 to 18.150. The intercepts and the biomass of minimum size (BMS) for A. corniculatum and S. apetala biotopes were higher than those in B. gymnorrhiza and Sporobolus virginicus biotopes. This result indicated that zoobenthic productivity in the A. corniculatum, and S. apetala biotopes were higher than that in the B. gymnorrhiza and S. virginicus biotopes. The intercept and BMS in fall were higher than those in other seasons, indicating that zoobenthic productivity was higher in fall compared to the other seasons.