7. Coarse woody Debris – Animals / Endangered Species

227.  The question is this - Looked for shrews – “specifically where” “how” “when” “how many times”?

228.  Symplastless trees, especially with soil contact act as a storehouse  for moisture providing moisture for plants and animals during dry times such as summer so called drought (Page-Dumroese, Harvey, Jurgensen and Graham, 1991).

229.  Preservation of a threatened or endangered species involves preservation of its habitat and the diversity that habitat entails. When such becomes a goal of forest management, managers need information not only on owls or small mammals, but also on the mycorrhizal fungi that form the base of the food web.  Removal of ectomycorrhizal tree hosts removes the energy source of ectomycorrhizal fungi, which will not fruit without their host plants (Amaranthus, Trappe and Bednar, 1994).

230.  Many insects and animals eat fungi and disperse the spores and probably occur through all decay stages of a tree.  The fungal grazers are food for predators, so the animal-plant interactions are a prelude to animal-animal interactions (Maser and Trappe, 1984, pg 29-par 2)

231. ...dying and symplastless wood provides one of the two or three greatest resources for animal species in a natural forest. ..if fallen timber and slightly decayed trees are removed the whole system is gravely impoverished of perhaps more than a fifth of its fauna (Maser and Trappe, 1984, pg1-par1).  ( The USFS practicing foresters call removal (killing) - “reforestation”).

232.  Certainly our knowledge of biological processes and their interactions within forest is incomplete, and we know too little about the cumulative effect of a wide range of stresses on the ecosystem. But integrative research at the ecosystem level shows clearly that the many processes operating within forest inter-connect in important ways. Further, diversity of microscopic and macroscopic plant and animal species is a key factor in maintaining these processes (Maser, Tarrant, Trappe and Franklin, 1988, pg1-par2). 
Maser et al. (1979) reported that 178 vertebrates use logs in the Blue Mountains 14 amphibians and reptiles, 115 birds, and 49 mammals; they tabulated use by log decay classes for each species.  Logs are considered important in early successional stages as well as in old- growth forests.  The persistence of large logs has special importance in providing wildlife with habitat continuity over long periods and through major disturbances (Franklin, Cromack, Kermit, et al. others,  1981).

233.  Logs become habitat for a variety of invertebrate species shortly after falling. CWD is used by invertebrates as a source of food, for nesting and brooding sites, for protection from predators and Environmental extremes, as a source of construction material, and as overwintering and hibernating sites (Samuelsson et al. 1994) (Voller and Harrison, 1998).   

234.  Debris has many functions ranging from soil protection to wildlife and microbial habitat. The management of coarse woody debris is critical for maintaining functioning ecosystems (Graham, Harvey, Jurgensen, Jain, Tonn and Page-Dumroese, 1994).

235.  Coarse woody debris plays numerous roles in providing habitat for organisms in ecosystems (Voller and Harrison, 1998).   

236.  Many invertebrates use or require particular species, and different communities of invertebrates occupy and use different decay stages  (Harmon al. 1986; Samuelsson et al. 1994) (Voller and Harrison, 1998).       

237.  Insectivorous species such as woodpeckers, small mammals and bears forage on insects dwelling in CWD (Maser et al. 1979; Maser and Trappe 1984; Samuelsson et al. 1994) (Tables 7.3 Id 7.4). Coarse woody debris has been found to provide thermal and security cover for a variety of small mammals in British Columbia (Voller and Harrison, 1998).      

238.  Forest floor diversity is partly maintained by windthrown trees that create a pit-and-mound topography as they are uprooted (Maser, Tarrant, Trappe and Franklin, 1988, pg34-par2).   

239.  About 140 years are needed for essential elements to cycle in large, fallen trees and more than 400 years for such trees to become incorporated into the forest floor; they therefore interact with the plants and animals of the forest floor and soil over a long period of forest and plant successional history (Maser, Tarrant, Trappe and Franklin, 1988, pg37-par2).   

240.  Symplastless trees are structural components of great importance for forest dynamics and forest biodiversity.  The decomposition of trees provides an important link in cycling of nutrients and essential elements in ecosystems.  In addition, many species of plants, fungi, and animals are dependent on symplastless trees for nutrients, essential elements, habitat or substrate and nesting (Kruys and Jonsson, 1999).

241.  Fallen trees that are oriented along the contours of a slope seem to be used more by vertebrates than are trees oriented across contours, especially on steep slopes. Large, stable trees lying along contours help reduce erosion by forming "a barrier to creeping and raveling soils.”  Soil, nutrients and essential elements deposited along the up slope side of fallen trees reduce loss of nutrients and essential elements from the site. Such spots are excellent for the establishment and growth of vegetation, including tree seedlings.  Vegetation becomes established on and helps stabilize this "new soil", and as invertebrates and small vertebrates begin to burrow into the new soil, they not only nutritionally enrich it with their feces and urine but also constantly mix it by their burrowing activities (Maser and Trappe, 1984 pg 4-par1&2).

242.  As a log decomposes, many organisms such as plant roots, mites, collembolans, amphibians, and small mammals, must await the creations of the inner space before they can enter.  The flow of plant and animal populations, air, water, and nutrients as well as essential elements between fallen tree and its surrounding increases as long as aging process continues (Maser and Trappe, 1984, pg 12-par1).

243.  The logs being removed would otherwise serve a key role as erosion control and animal activity (Page-Dumroese, Harvey, Jurgensen and Graham, 1991).

244.  Besides nitrogen, Calcium , Magnesium , Potassium, Phosphorus and other essential elements play key roles in soil, plant and tree health as well as the health of the other associated living organisms (Page-Dumroese, Harvey, Jurgensen and Graham, 1991).

245.  The interactions of fallen trees with soil are directly affected by steepness of slope and ruggedness of terrain; a fallen tree on flat ground, for example, is much more likely to contact the soil over its entire length than is one oriented either across or along contours on steep or rough terrain. The proportion of a tree in contact with the soil affects the water-holding capacity of the wood (Graham 1925). In our studies of fallen trees in old-growth Douglas-fir forests, the moisture retention through the summer drought was best in the side of trees in contact with the soil. The moisture-holding capacity of the wood affects in turn its internal processes and therefore the succession of plants and animals. In addition, the orientation of a fallen tree to aspect and compass direction and the amount and duration of sunlight it receives, drastically affect its internal processes and biotic community (Maser and Trappe, 1984 pg 4-par3).

246.  Various mites, insects, slugs, and snails feed on higher plants that become established on so called rotten wood.  These plants also provide cover for animals, as do the lichens, mosses, and liverworts that colonize fallen trees in decay class IV.  Wood-boring beetles, termites, and carpenter ants produce channels in heartwood (heartwood forming trees) that provide passageways for roots.  The fruiting bodies of the mycorrhizal fungi, produced from energy supplied by the host plant, can also be a major source of food for insects, arthropods, and small mammals such as the California red-backed vole (Maser and Trappe, 1984, pg 29-par 4). 

247.  As the bark becomes loose on a late class II fallen tree, lungless salamanders (Family Plethodontidae) join the internal community. Three species of salamanders are associated, as predators. with rotten 'wood in western Oregon: Oregon slender salamander, Oregon salamander, and clouded salamander (Maser and Trappe, 1984, pg34-par1).    

     248.  Decayed heartwood, i.e., of heartwood forming tree species, splits into chunks;  roots grow down the resulting cracks as well as along insect channels.  Invertebrates – from minute mites to centipedes, millipedes, slugs, and snails – find shelter in these openings and passage along them.  Vertebrates such as salamanders, shrews, shrew moles, and voles, find cover under debris of sloughed bark and so called rotten wood alongside the class IV tree; they also find the so called rotten wood on the underside of the tree crumbly enough for digging tunnels or burrows. Fungi and other microorganisms abound on the wood itself as well as on the new substrates offered by the feces of animals (Maser and Trappe, 1984, pg 17-par 4).   

249.  Colonization of decomposing wood by animals helps microbes to enter interior surfaces of the wood and creates additional openings for entry of water and essential elements; and penetration of the wood by roots of trees, such as western hemlock, facilitates entry by mycorrhizal fungi (Which is the base of the food web) (Maser and Trappe, 1984, pg19-par4).  

250.  One salamander, the clouded salamander, frequents so-called rotten wood, particularly Douglas fir in late classes II through IV.  These salamanders are often found under the loose bark of large fallen trees in spaces excavated by, wood - eating insects.  In fact, young clouded salamanders show a striking affinity for bark (McKenzie and Storm 1970).  It has been found twenty feet up in standing trees (Maser and Trappe, 1984,pg34-par6).      

251.  The final level of predation within large so called rotten, fallen Douglas Firs in class III through V is probably that of small mammals, such as shrews and shrew moles (Maser and Trappe, 1984, pg 35-par2).  

252.  Shrews are small, with short legs, tiny eyes, and long, pointed noses. Although they cannot see well, their senses of touch, smell, and hearing are acute.  The common shrew in western Oregon Douglas-fir forests is the Trowbridge shrew. This small, “nervous” mammal is abundant around fallen trees, particularly classes III and IV, that are well settled on the forest floor and have been in place long enough to act as shrew’s grocery.    The Trowbridge shrew has the most catholic diet of western Oregon shrews.  It eats at least 47 types of food, the most important of which are centipedes, spiders, internal organs of invertebrates (probably mostly beetles), slugs and snails.  In addition, it shows a definite affinity for fallen trees, as does some of its prey (Maser and Trappe, 1984, pg35-3).  The shrew-mole is ideally equipped to forage in and around fallen trees because its nose is extremely sensitive to touch, it is much like a blindman’s cane.  In almost constant motion, it quickly identifies any object it contacts.  Further, this mole’s size, adaptions for digging, and Herculean strength make it an efficient, burrowing predator within and beneath so called rotten wood (Maser and Trappe, 1984,pg35-par6).     

253.  Fungi feeders, E.g., California red-backed voles to black tailed deer, may obtain some of their protein nitrogen from decaying trees by feeding on fungal fruiting bodies, such as what some call truffles and mushrooms (Maser and Trappe, 1984, pg 36-par 3).        

254.  As a fallen tree decomposes, it creates a gradually changing myriad of internal and external habitats.  Plant and animal communities within a fallen tree are very different from those outside, but both progress through a series of orderly changes. As a fallen tree decomposes, its internal structure becomes simpler, whereas the structure of the plant community surrounding the fallen tree becomes more complex (Maser and Trappe, 1984, pg 36-par7).    

255. The manner, which a fallen tree comes to rest on the forest floor greatly, influences subsequent diversity of both external and internal plant and animal habitats.  The decomposing fallen tree provides a changing spectrum of habitats over many decades’ even centuries.  It provides diversity within a given successional stage and forms a physical-chemical link through the many successional stages of a forest (Maser, Tarrant, Trappe and Franklin, 1988, pg41-par4).  

256.  A fallen tree interacts with its environment through internal surface areas. A newly fallen tree is not yet a habitat for plants or most animals. But once organisms gain entrance to the interior they consume and break down wood cells and fibers. Larger organisms – mites, collembolans, spiders, millipedes, centipedes, amphibians, and small mammals must await the creation of internal spaces before they can enter.  The flow of plant and animal populations, air, water, and essential elements between a fallen tree and its surroundings increases as decomposition continues (Maser, Tarrant, Trappe and Franklin, 1988, pg42-par2).   

257.  A fallen tree oriented along the contour of a slope. The upslope side is filled with humus and inorganic material that allows invertebrates and small vertebrates to tunnel alongside. The downslope side provides protective cover for larger vertebrates. When under a closed canopy, such trees are also saturated with water and act as a reservoir during the dry part of the year (Maser, Tarrant, Trappe and Franklin, 1988,pg 45-fig 2.9).   

258.  Habitat Function.  Logs provide essential habitat for a variety of invertebrates and vertebrates. They are used as sites for lookouts, feeding and reproduction, protection and cover, sources and storage of food, and bedding. The high moisture content of logs makes them particularly important as habitat for amphibians (Franklin, Cromack, Kermit, et al. others,  1981). 

259.  Logs may contribute significantly to reestablishment of animal populations by providing pathways along which small mammals can venture into clearcuts and other bare areas. This has relevance to the reestablishment of tree seedlings on bared areas since survival and growth of new trees depend on development of appropriate mycorrhizal associations. Surprisingly, fungal symbionts apparently disappear from cutover areas shortly after their host trees are removed (Harvey et al. 1978a), and the sites must be reinoculated with their spores. Many mycosymbionts have underground fruiting bodies and completely depend on animals for dissemination of spores. Small mammals are the vectors. They consume the fungus and carry spores to new areas, thereby inoculating tree seedlings (Maser et al. 1978a, 1978b; Trappe and Maser 1978) (Franklin, Cromack, Kermit, et al. others,  1981). 

260.  Sound CWD provides secure travel corridors for small mammals (Maser et al. 1979; Maser and Trappe 1984; Carter 1993), and provides subnivean habitat during winter. The value of this habitat is positively correlated with piece size (Maser and Trappe 1984; Hayes and Cross 1987; Carter 1993).  Nordyke and Buskirk (1991) found that southern red-backed vole abundance was positively correlated with the decay stage of logs in the central Rocky Mountains.  Maser and Trappe, (1984) and Rhoades, (1986) reported associations of small mammals with CWD because of the food source provided by the fungal fruiting bodies growing in and on the CWD (Voller and Harrison, 1998).      

261.  Gyug (1993) reported that fur-bearers (martens and weasels) used clearcuts with logging debris more than those with no CWD; however, the level of use was much less than that of the adjacent forest (Voller and Harrison, 1998).     

262.  The value of CWD to mustelids (particularly martens, weasels, and fishers) is well documented (Baker 1992; Corn and Raphael 1992; Lofroth 1993; Buskirk and Powell 1994; Buskirk and Ruggiero 1994; and others) (Voller and Harrison, 1998).       

263.  Martens select habitats partly on the basis of thermal microhabitats (Taylor 1993), such as those provided by CWD (Lofroth 1993; Buskirk and Powell 1994; Buskirk and Ruggiero 1994). Corn and Raphael (1992) reported that martens selected subnivean access points that had greater volumes of CWD, more layering of logs, more sound and moderately decayed logs, and fewer highly decayed logs than random sites (Voller and Harrison, 1998).   

264.  NOTE page 200 – 201 has charts on animals known now to be associated with CWD (Voller and Harrison, 1998).       

265.  Aubry et al. (1988) found that some species of salamander were most abundant around CWD. Dupuis (1993) concluded that salamander populations in logged areas were limited by available moist microhabitats, primarily because of a lack of large logs in intermediate and advanced stages of decay (Voller and Harrison, 1998).         

266.  Salamanders use logs as reproduction sites, as foraging sites, and for cover, and also lay their eggs in them (Table 7.5 pg202) (Samuelsson et al. 1994) (Voller and Harrison, 1998). 

267.  Checklist of plants and animals – There are few checklists of either plants or animals that inhabit fallen Douglas fir in Pacific Northwest.  [Let alone in other areas with other species in the USA – (Termed as profiles or unique features)].   No checklist of the microorganisms in fallen trees of western old-growth forest is available [I know of none in the east.]; the subject has hardly been studied.  (Higher fungi have been cataloged for many kinds of so-called rotten wood in Europe.)  Lawton listed the mosses that occur on so called rotten wood or stumps in the Pacific Northwest.  Deyrup (1975, 1976) has done a thorough job with insects and has identified about 300 species associated with fallen Douglas fir.  The only published checklist for vertebrates that use fallen trees is for northeastern Oregon (Maser and others 1979 not listed in references here).   (Maser and Trappe, 1984, page 18-par 2)  

268.  Some of the mycorrhizal fungi that inhibit both mineral soil and so called rotten wood develop much more strongly in the wood than in the soil, and some appear to be restricted to so called rotten wood (Maser and Trappe, 1984 pg 29-par 1).  Mycorrhizae increase plant vitality and therefore such materials that strengthen the latter also increase survival of a species.

269.  Conclusion:  What purpose and need is there, that the capacity and ability, of CWD, to function as habitat, foraging sites, protection, reproduction sites, moist microhabitats, thermal microhabitats, secure travel corridors, lookouts, feeding site, sources and storage of food, bedding over many decades even centuries and a physical-chemical link through the many successional stages of a forest go unobserved in this “Burn and Clearcut Project”?



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