Inhabiting Leaf Litter Research Articles

Do mangrove diversity and leaf litter decay promote meiofaunal diversity?

The effects of mangrove diversity and the process of leaf litter decay on the diversity and community structure of meiofauna inhabiting leaf litter were investigated in a simple field experiment in a wet, tropical, soft sediment, mangrove forest in north-eastern Malaysia. Strings of freshly fallen leaves of Rhizophora apiculata and Bruguiera parviflora were placed on the mud surface in two adjacent subplots, each dominated by one of these tree species. The leaf strings were sampled weekly over five weeks and the nematodes and copepods found on the leaves were identified to species and enumerated. It is shown that, under similar conditions of sediment composition, salinity and tidal inundation, the species of mangrove tree or their leaves have little influence on leaf litter meiofaunal climax communities. Such differences as are apparent in the early part of the experiment are probably the result of differences in tree root structure, associated macrofauna and the initial chemical composition of the leaves. It is also shown that there are significant differences in the litter meiofaunal communities during the process of leaf litter decay. For the copepods, a distinct leaf litter community is characterized by the presence of members of the family Darcythompsoniidae and it is the completion of their lifecycle which is the principal feature of the community changes. Development of the nematode community is characterized by subtle shifts in the composition of species inhabiting the leaf litter. It is suggested that changes in the meiofauna community may be more intimately linked to successional changes in the chemistry and/or microflora of the leaf litter than to the physical breakdown of the substratum.

Origins and Distribution of Two Species Groups of Schizomida, (Arachnida)

Two species groups of schizomids occur in California and Arizona. Their low vagility and inability to disperse through suboptimal areas make their present distribution largely a product of the geologic and climatic events since the Miocene. The relictual nature of most schizomid populations testifies to the vicis- situdes of the northerly latitudes during the Pleistocene and Recent epochs for these Neotropical-Tertiary and Madro-Tertiary representatives. The arachnid order Schizomida contains about 75 species, mainly tropical; however a few taxa are present in temperate areas in Cali- fornia and Arizona. Little is known of the feeding habits of schizomids, but they prob- ably prey upon small invertebrates throughout life. Six instars occur in a period of 2-3 years. Schizomid habitats are characteristically moist and dark. These arachnids are extremely sensitive to dessica- tion and therefore inhabit leaf litter and cavities beneath rocks and logs where adequate moisture is present. Moist habitats become scarce in California in late spring and schizomids decrease in abundance at this time, likely retreating into the soil until autumn rains arrive. This habit enables temperate schizomids to survive in a macroclimate quite different from that of the humid tropics. The low vagility and inability of schizomids to disperse through suboptimal areas may account for their geographic distribution. They lack any secondary means of travel, such as phoresy, ballooning, resistant eggs, parasitism or other means employed by archnids. A few species, such as Trithyreus joshuensis Rowland (1971), and T. borregoensis Briggs and Hom (1966), are found in very restricted habitats. Both species are limited to small desert palm oases. Other California taxa such as an undescribed subspecies of T. pentapeltis (Cook, 1899) and T. belkini McDonald and Hogue (1957) range more widely. These occur in many locations in mountain foothills and canyons at low elevations. The highest elevation recorded for schizo- mids in California is for T. joshuensis at about 2400 ft. Snow occasion- ally falls here and summer temperatures are very high. This climate

Studying Microarthropods Inhabiting Leaf Litter

Leaf litter contains many interesting forms of life that most high school students and teachers have not observed. The object of this article is to encourage students and teachers to study the organisms inhabiting the leaf litter and to describe the materials and procedures involved in making such a study. The existence of any ecosystem depends upon the cycling of the essential elements that make up protoplasm and the continual flow of energy from one trophic level to the next (Odum, 1959). Many times these essential elements become trapped at a specific level. A specific level where materials are slowed down and trapped is the leaf litter. Before these essential elements can be recycled through the ecosystem, they must be broken down into smaller units.. Breakdown of litter is important to man because it releases important elements that would otherwise remain trapped and would not be available to plants for recycling in the ecosystem. This breakdown of leaf litter or decomposition results from the action of various decomposing organisms. Major decomposers of organic matter, including leaf litter, are bacteria and fungi (Odum, 1959). Others agents that break down and act on leaf litter are microarthropods. The main function of microarthropods is physically breaking up leaf litter, thereby increasing its surface area so that chemical breakdown will occur more rapidly through the action of bacteria and fungi. Not all organisms that inhabit the leaf litter contribute to its breakdown. Various Lepidoptera, Coleoptera, and Diptera inhabit the leaf litter without directly breaking down the organic matter (Fenton, 1947). This article will concern itself with all microarthropods whether they contribute to leaf litter breakdown or not.

A Litter‐Bag Method for the Study of Microarthropods Inhabiting Leaf Litter

BS>A botanical method is described for use in sampling leaf litter in studies of succession of microarthropod species. This method uses fresh leaf litter in net bags that are placed on the forest floor. Sampling at intervals permits estimates of the rates of breakdown of the litter. During such studies it was found that microarthropods invade the bags freely and can be extracted with Tullgren funnels. An anaiysis of data indicated that the bags tended to produce high populations. The use of dm/sup 2/ litter bags was found to produce best results for quantitative sampling for Tydeus sp. and possibly other species. (C.H.)