Oiii Ijviiit; Rcxoiirces — Plains 



19^ 



Fiy. 3. L\iniluiii'ilus iibantis. riie chaiUcrclIc i.s one ol llic 

 iiiipoitanl fungi forming mycorrhizae with pines and oaks 

 in North American forests. 



Declining Fungi 



Change in the frequency of occuirence of 

 macrofungi in Europe is well documented; 

 many species that form ectoniyconhizae (a kind 

 of mycorrhizae; see glossary) are showing a 

 marked decline, and some species involved with 

 wood decay show a marked increase in fruiting. 

 More than 30'7r of the reported species of mush- 

 rooms in Europe occur on at least one country's 

 "Red List" (see glossary: "red data book") 

 (Arnolds and de Vries 1993). and once-common 

 species such as Hydnum repcmdiim and some of 

 the chanterelles (Fig. 3) appear lost from some 



countries. Air pollution, particularly acid rain, 

 has been implicated in this observed decline in 

 ectoniycorrhizal fungi fruiting frequency and 

 diversity in Europe (Fellner 1993; Pegler et al. 

 1993). Intensive collecting of edible fungi such 

 as chanterelles, Hydnum. and boletes might also 

 be negatively affecting fruiting patterns of these 

 fungi, but additional data are needed to docu- 

 ment this. In any case, the observed change in 

 fungal fruiting is correlated with a decline in 

 forest health, but cause and effect are hard to 

 document. Rigorous studies to determine if sim- 

 ilar trends in macrofungi fruiting patterns have 

 occurred in the United States do not exist. 



Current Studies of Diversity 



The baseline data necessary for estimating 

 fungal diversity and for investigating trends in 

 fruiting patterns and frequencies of macrofungi 

 in the United States and Canada are not yet 

 available although various methods are begin- 

 ning to be used to obtain these necessary data. 

 For example, studies of species diversity and 

 frequency of particular fungi in Pacific 

 Northwest old-growth forests have documented 

 that while a single season of collecting will 

 uncover most of the decomposer macrofungi, 

 mycoiThizal fungi fruit much more enatically 

 (Vogt et al. 1992). Thus, to develop a reasonable 



Most Americans identify truffles as 

 expensive. Epicurean delights from 

 Europe, found with the aid of pigs. Because 

 truffles are produced belowground, we 

 remain ignorant of the rich diversity and 

 importance of truffles in North America. 

 Truffles (ascomycetes) and the similar- 

 appearing false truffles (basidiomycetes) 

 play a major role in determining the struc- 

 ture and function of forest ecosystems by 

 providing nutrients to many economically 

 valuable trees in exchange for carbohydrates 

 from the trees. This mycorrhizal (fungus 

 root) symbiosis is obligate; that is, truffles 

 and trees, especially conifers, cannot survive 

 without each other One of the problems in 

 reforesting large areas of the Southwest is 

 identifying ectomycorrhizal fungi suitable 

 for inoculation of tree seedlings destined for 

 sites with calcareous soils. 



Truffles and false truffles are food items 

 for many animals, including many endan- 

 gered or threatened species. In old-growth 

 Douglas-fir (PseudoJsuga inenziesii) forests, 

 truffles not only provide soil nutrients to the 

 trees controlling forest structure, but they 

 also are an important link in the food web 

 supporting the endangered spotted owl. 

 Northern (lying squirrels {Glaucomys sahri- 

 ims) glide down to the forest floor at night to 



Truffles, Trees, and 

 Biodiversity 



by 



Robert Fogel 



University of Michigan 



feed on truffles. While feeding on truffles, 

 flying squirrels becoine vulnerable to preda- 

 tion from the northern spotted owl (5/n.v 

 nccidenlalis cauiina), coyotes (Canis 

 latmns), bobcats (Lynx nifiis), and other 

 predators. 



Given the undeniably important role of 

 truffles in determining the structure and 

 function of forest ecosystems, how much is 

 known about the distribution of truffles and 

 false truffles'? The paucity of information 

 and potential iinpact of surveys on our 

 knowledge base can be illustrated by an 

 ongoing National Science Foundation-fund- 

 ed survey of the Great Basin, an area of 

 712,250 km- (275,000 mi-) between the 

 Sierra Nevada and Wasatch mountains and 

 including most of Nevada and parts of 



California, Idaho, Utah, Wyoming, and 

 Oregon. No truffles or false truffles had been 

 reported from the area before the survey. 

 0\er three summers, the survey produced 

 1,119 collections of truffles and false truffles 

 from 40 mountain ranges. 



In addition, the survey produced evi- 

 dence for extinction of many truffles in the 

 Great Basin. A few truffles obligately asso- 

 ciated with a single tree species outside the 

 Great Basin have switched within the Great 

 Basin to new tree species, providing sup- 

 porting evidence for extinction of local tree 

 species. New endemic species have been 

 found and the geographic ranges of some 

 species greatly expanded. Populations of 

 some endemic species are restricted to a sin- 

 gle mountain range. 



Knowledge of truffles is important to the 

 biodiversity in the United States. Without 

 such knowledge, there is a danger of losing 

 or degrading ecosystems through ignorance 

 about the status of keystone fungal species. 

 If ecosystems are lost, then species depen- 

 dent on specific ecosystems will also be lost. 



For more information: 



Robert Fogel 

 University of Michigan 

 Ann Arbor, MI 48109 



