摘要
Physiognomical features,ecology and geopedological factors of the vegetation of somecalcareous-dolomitic massifs in the Lombard Pre-Alps(Northern Italy).I.Natural and seminatural grasslands.Natural and semi-natural grassland vegetation of calcareous-dolomitic Lombard Pre-Alps has been investigated,with synecological approach.Some physiognomical and ecological types have been identified and environmentalfactors have been described.A.Under the timberline:—discontinuous xerophylous sedge communities,dominated by Carex mucronata and creeping chamaephytes,and Festuca alpestris formation on extremely dry ridges with discontinuous soils.—Festuca spectabilis formation,pioneering dry stabilized detritus in mountain belt.—Sesleria varia-Carex humilis thermophilous communities,with Bromus erectus codominance,widelydiffused on steep sunny slopes with grey rendzina,in the submediterranean belt.—Caricion austroalpinae calcophilous communities.Sesleria-grasslands,rich in prealpine endemic element,are situated on cool slopes at low altitudes too.They are marked by Molinia coerulea.In the Fagus belt,Caricion austroalpine communities spread also in southern exposition.Here the Sesleria-vegetation isqualified by an endemic group that takes the place of thermophilous submediterranean elements.—Molinia coerulea neutral-acidic communities,on low permeability soils(《Terra Rossa》and its colluvium;soils on glacial deposits)and M.coerulea hygrophilous communities,along little valleys close to perennialsprings,in the submediterranen belt.—Schoenus nigricans hygrophilous formation,strictly connected with dripping springs,on travertines orhydromorphyc soils.B.Above the timberline:—Caricion austroalpinae calcophilous communities.The most widespread type is Carex sempervirens and S.varia dry grassland,rich in prealpine endemic element.It characterizes sunny slopes.Helictotricon parlato-rei becomes dominant where the substratum is highly percolating.On the contrary,at higher humidity,onhumiferous soils in the high-mountain-sub
Physiognomical features,ecology and geopedological factors of the vegetation of some calcareous-dolomitic massifs in the Lombard Pre-Alps(Northern Italy).I.Natural and seminatural grasslands. Natural and semi-natural grassland vegetation of calcareous-dolomitic Lombard Pre-Alps has been investigated, with synecological approach.Some physiognomical and ecological types have been identified and environmental factors have been described. A.Under the timberline: —discontinuous xerophylous sedge communities,dominated by Carex mucronata and creeping chamaephytes, and Festuca alpestris formation on extremely dry ridges with discontinuous soils. —Festuca spectabilis formation,pioneering dry stabilized detritus in mountain belt. —Sesleria varia-Carex humilis thermophilous communities,with Bromus erectus codominance,widely diffused on steep sunny slopes with grey rendzina,in the submediterranean belt. —Caricion austroalpinae calcophilous communities.Sesleria-grasslands,rich in prealpine endemic element, are situated on cool slopes at low altitudes too.They are marked by Molinia coerulea.In the Fagus belt, Caricion austroalpine communities spread also in southern exposition.Here the Sesleria-vegetation is qualified by an endemic group that takes the place of thermophilous submediterranean elements. —Molinia coerulea neutral-acidic communities,on low permeability soils(《Terra Rossa》and its colluvium; soils on glacial deposits)and M.coerulea hygrophilous communities,along little valleys close to perennial springs,in the submediterranen belt. —Schoenus nigricans hygrophilous formation,strictly connected with dripping springs,on travertines or hydromorphyc soils. B.Above the timberline: —Caricion austroalpinae calcophilous communities.The most widespread type is Carex sempervirens and S. varia dry grassland,rich in prealpine endemic element.It characterizes sunny slopes.Helictotricon parlato- rei becomes dominant where the substratum is highly percolating.On the contrary,at higher humidity,on humiferous soils
