Pm. Catling et Vr. Brownell, Importance of fire in alvar ecosystems - Evidence from the burnt lands, eastern Ontario, CAN FIELD-N, 112(4), 1998, pp. 661-667
Vascular plants recorded within 50 one metre square quadrats in 1997 in an
area cut and burned 37 years earlier revealed an unusually high species div
ersity with 87 native vascular plant species, which is roughly twice as hig
h as that recorded in various open areas of alvars that have not recently b
een burned. Site conditions appear to have favoured native species over wee
dy aliens, the latter accounting for 21% of species in quadrats, but having
low cover values. The sampled area was dominated by graminoid plants and s
hrubs, and was transitional between alvar shrubland and alvar grassland. Th
e saplings present were mostly Trembling Aspen, Populus tremuloides, and Wh
ite Spruce, Picea glauca. The cut and burned area included 16 rare and/or r
estricted species. Some of the prominent vascular plants serve as larval fo
odplants for restricted butterflies, and the high species diversity and mor
e mesic conditions in successional openings ensure adequate adult nectar so
urces. The burned site also provided habitat for rare birds. Considering th
ese observations and because the vast majority of alvars have burned within
the past few centuries, it is concluded that successional alvar burns dese
rve recognition as an important part of the alvar ecosystem and that burnin
g of an alvar habitat is an appropriate management consideration. Managemen
t plans should account for certain fire-susceptable features such as ancien
t trees and arthropod populations.