Our Liviiii; RcsDiirces — Interior West 



M9 



HUACHUCA 



number of sites for rare or insular plants, their 

 abundance at each site, and other species diver- 

 sity indices are lacking for many species of 

 concern. The areal extent, age class, stmctural 

 characters, and regeneration rates of the five or 

 six biotic communities on the sky islands are 

 poorly known, especially for oak woodlands 

 (McPherson 1992). 



Fungi have been intensely inventoried on 

 the Chiricahuas. though only partial inventories 

 exist for ranges of mycorrhizal hypogeous 

 fungi, truffles, and false truffles (States 1990; 

 Nishida et al. 1 992 ). The lichen flora, one of the 

 most diverse and complex in western North 

 America, is poorly inventoried for almost all 

 the sky islands. 



The highest sky islands, except the 

 Peloncillos and the Animas, have been intense- 

 ly inventoried for all groups of insects (C. 

 Olson. University of Arizona, personal commu- 

 nication). Spider and pseudoscorpion distribu- 

 tion is poorly understood. The larger millipedes 

 and scorpions have been extensively collected, 

 but the micro-millipedes, the insular flightless 

 beetles, and the flightless grasshoppers in the 

 upper elevations are poorly known. For 

 instance, a 6-week survey on top of the 

 Pinalenos yielded three new species of flight- 

 less beetles (Warshall 1986). 



The land moUusks have been inventoried 

 (Bequaert and Miller 1973), though their range 

 extensions and laxa need review. The cienaga 

 (wetland) mollusks are being studied by the 

 Smithsonian. Fish, birds, amphibians, reptiles. 

 and mammals are well-inventoried and yield 

 continuing surprises such as the recent discov- 

 ery of the Ramsey Canyon leopard frog {.Rami 



OPOSURA 



siihaqiiavocalis). Specific inventory and moni- 

 toring gaps in frequency and abundance of sen- 

 sitive species remain. 



Flora and Fauna 



A major dividing line between the flora and 

 fauna of southern and northern origins occurs in 

 the sky island ecoregion. The sky island com- 

 plex harbors more than 2,000 plant species. Of 

 the more than 190 snail species in the 

 Southwest, the sky islands support 3 endemic 

 genera, and over 60 endemic species, including 

 the genus Sonorella and the monotypic genus 



Fig. 2. Cross-sections of tliree 

 sky islands shiowing tlie "stacked" 

 biotic communities varying witli 

 latitude. Ttie Wtiite Mountains are 

 close to tlie Rocky Mountain llora 

 and fauna. The Oposura 

 Mountains begin to sliow the full 

 developiTient of the Sierra Madre 

 communities (Marshall 1957). 



Table 1. Sky island forested 

 ecosystems of Arizona and New 

 Mexico. 



