Effect of forest disturbance on myxomycete assemblages in the southwestern Peruvian Amazon

Although the effects of microenvironmental factors on distribution patterns in myxomycetes have been investigated,studies of the responses of this group of organisms to different regimes of forest disturbance are relatively few in number.In an effort to understand the implications of forest fragmentation and habitat loss on myxomycetes,the project described herein was carried out at the Los Amigos Biological Station in southeastern Peru.The structure and composition of assemblages of myxomycetes were investigated in relation to three different forest types and climatic periods in the area of study.An analysis of the most commonly recorded substrates was carried out as well.The results suggested that habitat loss,through differences in forest structure,was the factor determining most of the differences in fruiting body abundance of myxomycetes among forest types.In addition,a switch in the ecological strategy of dispersal seemed to be an important factor accounting for differences in the fruiting body abundance and structure of assemblages of myxomycetes between collecting periods.This study provides evidence indicating that for microbial assemblages to maintain the balance of functional interactions within a particular forest ecosystem,the conservation of the forests themselves should be considered.

Myxomycetes in a forest affected by great cormorant colony:a case study in Western Lithuania

Myxomycete distribution patterns were investigated in a colony of great cormorants(Phalacrocorax carbo sinensis)established in a pine forest in the Curonian Spit,western Lithuania.Ornithogenic impact on the forest resulted both in vegetation changes and altered types and characteristics of myxomycete substrata.The lowest myxomycete species richness was found in the most active part of the colony with the newest and most numerous nests.The myxomycete assemblages of the active part of the colony also showed the biggest differences from the reference zone(oligotrophic pine forest).The general abundance of myxomycetes in the territory of the colony was higher due to the presence of the species that are not characteristic of pine forests.The most abundant species in the territory were Badhamia apiculospora and Perichaena cf.corticalis.Along with other facultative coprophiles,such rare species as Comatricha mirabilis and Arcyria leiocarpa were found sporulating in the colony.The Bray-Curtis ordination revealed a tripole gradient of myxomycete distribution in the colony.It was hypothesized that the first continuum may reflect myxomycete assemblage transition from hypertrophic to oligotrophic habitat;the second continuum may reflect myxomycete assemblage distribution from habitats with limited diversity of available substrata,extreme levels of nutrients and high pH to habitats with high diversity of available substrata,moderate to high levels of nutrients and pH,and the third continuum may reflect myxomycete assemblage distribution from habitats with lower diversity of available substrata,low levels of nutrients and pH to habitats with high diversity of available substrata,moderate to high levels of nutrients and pH.