Monday, May 4, 2009

The Ecosystem of Decomposing Tree Stump


Phylum: Basidiomycota (Club Fungi)
The phylum Basidiomycota, also known as club fungi, hosts about 25,000 or more species. This type of fungus reproduces sexually forming spores on a basidia that is club-shaped.
Bracket fungi or shelf fungi produces a shelf-or-bracket shaping fruiting bodies that lies in a close planar grouping of separate or interconnected horizontal rows found on trees.
They are tough and sturdy therefore, produces spores called basidiospores in the pores of the organs to make up the undersurface (Bracket Fungi).
The phylum Ascomycota which is also called the sac fungi digest resistant material such as cellulose (found in the cell wall of plants), lignin (material found in wood), and collagen (connective tissue in animals). Overall, Ascomycota species form lichens-- symbiotic relationship between algae and fungus with cyanobacterium in which they reproduce sexually and asexually (Kingdom Fungi).
Lichens and moss on decaying tree stump Rainforest near Mt. Baker, WA; http://www.flickr.com/



The Polypores (Polyporaceae)
This group contains two hundred and fifty British species in eleven genera. In superficial appearance many of them are not unlike some of the Agarics, but the gills of the latter are here replaced by a mass of compacted tubes, of which the lower surface appears punctured by a multitude of pores, round or angular, occasionally sinuate or torn (Rolfe).
In some genera, as Boletus, the plant is terrestrial, and has an umbrella-shaped cap, supported on a stout central stem. In others such as Merulius and Poria, the fruiting body is flat and crust-like; the mouths of the pores, which in some species are mere shallow depressions, appearing on the free surface (Rolfe).
In the vast majority, however, are those forms, like Polyporus, Polystictus, Fomes, and Fistulina, which appear as bracket-shaped, or hoof-like masses adhering to trees, both living and dead. In the Polypores, the fruiting body shows every variation of consistency, from the soft and juicy through the leathery varieties, to those really woody. The latter are perennial, and their annual layers of growth may be easily traced (Rolfe).


On the account of their arboreal habitats, many of these species are very destructive in woods and forests. Merulius lacrymans is the agent of “dry rott” in houses, and is discussed more (Rolfe).
The Toothed Fungi (Hydnaceae) in which the spore-bearing surface is spread over spines, teeth, tubercles, papillae, or wart-like folds, which take the place of gills in the Agarics and the tubes in the Polypores. The Hydnaceae are represented in Britain by nine genera, containing in all about one hundred species. Of these, a few have a central stem, and conform more or less to the orthodox parasol-like shape; but most of them resemble hedgehog-like masses, or else fleshy or leathery crusts of various shapes, bearing the spine-like process on the lower, or the free, surface (Rolfe).
In the largest and best known genus, Hydnum, of which there are some fifty species, the spines are large and almost awl-like. From this, they vary in shape and prominence, in the different genera, down to Phlebia, which has radiate body shows also every variation and maybe gelatinous, fleshy membranous, wax-like or leathery. Many of them are terrestrial and are found in woods or on heaths; others inhabit decaying logs, while some are known to attack living trees. Most of the fleshy kinds are edible; none is considered poisonous (Rolfe).
The Leathery Fungi (Thelephoraceae) contains a heterogeneous collection of fungi, numbering about one hundred and fifty species, contained in eleven genera, whose identity, in the absence of a microscope, is often difficult to determine.
In general, they have a smooth, flat or slightly undulating hymenium, spread over the exterior of an irregular cup-like body, the free surface of a prostrate crust, or the lower surface of a bracket-shaped body. In most cases their consistency is membranous or leathery, through occasionally waxy or even gelatinous (Rolfe).
The members of the order have no particular points of interest except that all the species of Craterellus are edible, C. cornucopioides being formerly sold in Convent Garden market, while of the other genera, many species are destructive pests. In this connection, it may be made of Stereum purpureum, which is the cause of “silver leaf” disease of plum, apple, and similar fruit
trees, and Coniophora cerebella, which is one of the fungi causing dry rot in buildings. The latter is particularly dangerous in that it paves the way for Merulius lacrymans (Rolfe).
Fairy Clubs (Clavariaceae) contains some of the most graceful fungi known. Most of them are small in stature, delicate in appearance and often bright in colour. Of the sixty or so British species comprised in six genera, forty alone are contained in the genus Clavaria, in which the fruiting bodies occur as small erect tufts of simple or much branched clubs; many of the
latter having an elaborate antlered or coral-like appearance. In Sparassis, the fruiting body is so much divided that it resembles a cauliflower. In Calocera, which has a superficial resemblance to Clavaria, the clubs are gelatinous, becoming horny when dry (Rolfe).
Most of the Club fungi are found among grass in meadows or woods, upon lawns. A few inhabit decaying stumps, dead leaves, etc. All of the larger kinds are edible; none is known to be poisonous (Rolfe).
The Ecology of Mosses and Ferns
Mosses (Musci)
are initially from the phylum Bryophyta with a reference of being just simple green land plants with leaves and a stem, but do not have roots. There are approximately 14,500 species of mosses.
Many mosses have only one thick cell, except for the midribs, which are very often present. They can also reproduce asexually, by means of small clusters of cells or plates of tissue which break away and germinate in becoming new plants. Most mosses are found in areas with a humid and cold to moderate warm climate (Parmentier).
Some mosses may also have rhizoids involve in which they could be multicellular. The stem shows some internal differentiation into hydroids and leptoids which are like xylem and phloem (transporting oxygen) of higher plants but very simply organized with no connection to leaves or other branching stems. Mosses can tolerate dry spells by drying out therefore; it is required for abundant water for growth and reproduction (Mosses).
Ferns are an ancient family of leafy plants that grow in moist areas under forest canopy. They are vascular plants with the development of internal vein structures that promote the flow of water and nutrients. Unlike others, ferns consist of a reproduction of spores and an intermediate plant stage called a gametophyte (About Ferns).
The leafy branch of the fern is usually called a frond. The small leaflets which make up the whole frond are called pinnae. Adult ferns can survive with moisture in the air and nutrients in the soil, light for photosynthesis and consistent temperatures, and protection from the humidity (About Ferns).


The Life History of a Mushroom
If, then, a brick of mushroom spawn, which acts as the basis for the cultivation of this esculent, which is obtained from a nurseryman, and is carefully examined, it will be found to consist of a compressed mass of compost, permeated in all directions by a vast network of minute interwoven branching whitish threads, in appearance not unlike a loose weft of wadding (Rolfe).
This system, which is known as the mycelium, constitutes the vegetative portion of the mushroom plant, and is part concerned with growth and nutrition. The function of this organ is to absorb, from the organic materials of the mushroom bed, the food requisite for its own development, and for the eventual production of the fruiting bodies. It is in this respect analogous in a sense to the roots, stem, and leaves of a flowering plant (Rolfe).
In the production of Fruiting bodies, the spawn is placed in a mushroom bed, this dormant mycelium springs into life, and runs or spreads in all directions, gradually permeating the compost. Having reached a suitable stage of development, the threads of the mycelium near the surface of the bed bunch themselves together, here and there, into small knots, which enlarge, take shape, and eventually burst through the surface of the bed in the form of button mushrooms. The buttons continue to expand, resulting in the mature specimens with which everyone is familiar (Rolfe).
These mushrooms constitute the reproductive portion of the fungus, and may be termed the fruiting bodies. Their function is to produce and liberate spores, the microscopic mushroom seeds. A mushroom consists of an umbrella-like cap, supported on a stout stem, and bearing on its lower surface, radiating outward like the spokes of a wheel, a number of vertical knife-life plates, known as the gills, which are covered with the spore-bearing surface or hymenium.

Thursday, April 30, 2009

The Ecosystem of a Decaying Tree Stump

In biological terms, an ecosystem means the interactions of organisms living together in a particular place and among those organisms and their abiotic environment, in which they are complex because each organism responds not only to other organisms but to the conditions in the atmosphere, soil, and water. The Ecosystem management is heavily involved in the process of conservation approach that emphasizes multiple restoring and maintaining the quality of an entire ecosystem rather than concentrating on the conservation of individual species which makes the use of certain acknowledgement of particular organisms, habitat and climatic temperatures.
During our research and observation, I have discovered that many species develop over a certain period. Over several days rain occurred in the first two weeks of March, and as soon as the humidity changed after the occurrence of the rain, some species such as mushrooms started the formation blossoming. Climate changes evolved over time because of the excessive weather in temperature changes. I have also learned that water and temperature are most likely the two basic abiotic factors that have the greatest affect on organisms in the habitats of ecosystems. Also, during our observation, we have discovered that these particular species showed in our research are most commonly found in habitats and how they have the most magnificent formations.
This research is based on the ecosystem of a decomposing stump, but we have included research on a log too. We proceed in discussing mainly three particular phylums: Ascomycota, Bryophyta, and Basidiomycota. Also, we will discuss various types of different fungus that have occurred throughout the temperature changes in the humidity of February and March.

An ecosystem in a decaying stomp can be determined by a classification of specific types of species and organisms. A decaying wood is usually more important than that of a living tree because it provides a good shelter for most organisms.
Dead and dying trees play a vital role in the functioning and productivity of arboreal ecosystems through effects on biodiversity, carbon storage, soil nutrients cycling, energy flows, hydrological processes and natural regeneration of trees.
Due to the decaying process, changes in moisture content will cause the wood to shrink or crack; it could become unstable and cause a potential hazard. It may be necessary to reduce the size of the piece of decaying wood or to re-erect it.
During the aging process and through the activity of wood digesting organisms, the tree progressively develops features such as hollowing, decaying wood and water pools. The tree is gradually transformed into a complex of habitats with often unique combinations of niches for many species, established sometimes over many centuries.
The natural tendency to lose branches, to hollow and decay may initiate an adaptive growth process in the tree to compensate for potential weaknesses in the wood strength which may appear as a localized deformation i.e. a change in the shape of the trunk or branch.
There are two distinct types of decaying wood habitat. The first is associated with standing dead trunks, limbs or branches left around the outside of the tree, while the second is found within the trunks and branches in which the decay forms cavities (Cowan).
The decaying wood inside living trees decomposes from the inside out, forming cavities, rot holes and hollow trunks, which are created by invertebrates and fungi, but it goes to provide shelter for biodiversity of birds, small mammals and reptiles (Cowan).
Most resources perform vital ecological roles that vary in different biological transformations and the cycling of nutrients, decomposition, and respiration. Although, these roles affect ecosystems, it also affects the health and the production of soil. Down wood is also a major source of mychorrizal fungi, so it retains moisture and serves as important reservoirs of such fungal activity during dry summer months (Marcot).
Decaying wood is a major contributor to humus and organic matter which helps to maintain or improve the structure of soil in the production of nutrients. Nitrogen is available in the soil of forests found in matter of woody material which creates a condition of acid in a microbial activity that fixes up nitrogen (Marcot).