Differences in lichen and bryophyte communities between old-growth and managed second-growth forests in the Swan Valley, Montana

Abstract

Lichen and bryophyte communities differed between managed second-growth and unmanaged old-growth grand fir forests in northwestern Montana in all three strata examined: lower canopy, trunk, and ground. Old-growth forests had larger trees, greater structural diversity, greater volumes of coarse woody debris, fewer species of vascular plants, more species of trunk epiphytes, higher β diversity, and higher γ diversity than second-growth forests. Although pendent fruticose lichens were common in both stand age classes, species of Alectoria were more abundant in old growth, while second growth was dominated by Bryoria spp. Nitrogen-fixing foliose lichens were more common in all strata of old growth, and Lobaria pulmonaria, a common N-fixing species in old growth, was absent in second growth. Cladonia spp. were more numerous in second-growth forests. Nearly all species of leafy liverworts were more common in old growth and typically occurred on rotting wood. Many of these liverworts were absent from second growth. Our results suggest that many species of lichens and bryophytes find optimum habitat in old-growth forests and that these species will become less common as silvicultural practices continue to convert old growth to younger aged forests. Key words: bryophytes, diversity, forests, lichens, Montana, old growth.

Analisi quali-quantitativa del legno morto in soprassuoli non gestiti: il caso di "Bosco Pennataro", Alto Molise

“…Nelle opportune proporzioni, commisurate anche alle finalità di coltivazione della foresta, la presenza del legno morto è quindi fondamentale per il mantenimento della biodiversità, rappresentando il microhabitat di centinaia di specie di invertebrati (HELIÖVAARA e VÄISÄNEN, 1984;KIRBY e DRAKE, 1993;SAMUELSSON et al, 1994;SIITONEN, 2001;HARMON et al, 1986), funghi (HEILMANN-CLAUSEN, 2001;MASON, 2003;SIPPOLA e REN-VALL, 1999;RYDIN et al, 1997), briofite (SÖDERSTRÖM, 1988;LESICA et al, 1991;ÓDOR e STANDOVÁR, 2001), licheni (HUMPHREY et al, 2002, anfibi (HERBECK e LARSEN, 1999;RAYMOND e HARDY, 1991), piccoli mammiferi (HARMON et al, 1986) e uccelli (SANDSTRÖM, 1992; MIKUSINSKI e ANGEL- STAM, 1997;MASON, 2003). È stato ad esempio rilevato che tra il 20% e il 40% delle specie di uccelli in una comunità forestale dipende dalla presenza di cavità in alberi morti (HUNTER, 1990;MCCOMB e LINDENMAYER, 1999), mentre STOKLAND et al (2004 evidenziano come nei paesi scandinavi circa 6000-7000 specie dipendano dalla presenza del legno morto.…”

Edge effects on the lichen genus Lobaria in Atlantic Canadian Forests

“…The three species examined occurred on average 12.12 m from the edge of the harvest. Lichens that are sensitive to disturbance are those that have narrow microhabitat requirements (Lesica et al 1991, McMullin et al 2013. Lobaria pulmonaria was the most tolerant to edge effects that we assessed.…”

“…Old-growth and mature forest habitats are rich with lichen species, including many that are not typically found in younger forests (Lesica et al 1991, McMullin et. al.…”

Líquens e outros organismos epifílicos em Conchocarpus macrophyllus J.C. Mikan no Parque Estadual do Rio Doce, Minas Gerais, Brasil

“…Alguns líquens epifílicos são importantes fixadores de nitrogênio, que pode então ser absorvido pelo forófito (Bentley & Carpenter 1984, Benzing 1990, Lessica et al 1991, enquanto outros podem chegar a causar danos aos hospedeiros, como é o caso de algumas espécies que liberam fitotoxinas (Benzing 1990). …”

“…Considera-se que o número de espécies de líquens epifílicos é menor em florestas montanas, em vegetação perturbada ou secundária e em florestas semidecíduas ou áreas secas, onde são quase ausentes (Lessica et al 1991, Lücking 1995, 1997a.…”