These mobile groups consist of millions of individuals and are highly destructive to vegetation.
Where it occurs at moderate intensity, grazing can be very destructive to alpine vegetation, which cannot easily cope with disturbance in its already environmentally stressful state.
Mountain goats, introduced in small numbers in the 1920s, numbered more than 1,000 a few decades later; they became increasingly destructive of area vegetation, and efforts began in the 1980s to control their population (it was down to a few hundred by the early 21st century).
Ecological methods included conducting destructive harvesting on vegetation; soil analyses and a soil seed bank assessment as well as using allometric equations to estimate the biomass and carbon contents of P. juliflora.
Although emplacement of thin tephra is usually less destructive of the vegetation cover it is not clear whether erosion of thin tephra is similarly rapid, or whether preservation is more or less likely.
Brandon Nida, one of the march's organizers and native West Virginian, said he expected thousands of people will converge on the tiny town of Blair, W.Va., for the protest, which plans to highlight the destruction caused by of mountaintop removal, an environmentally destructive surface mining practice where vegetation and earth are blasted away to expose the coal underneath.
These destructive habits sometimes transform woody vegetation into grasslands.
The data for allometric models for estimating biomass in woody vegetation comes either from destructive or from non-destructive methods.
Swamp buggies, which ride on immense tractor-style tires and can weigh tons, are especially destructive to the soft soils and sensitive vegetation in the swamp, ecologists say.
Finally, the restricted movements of besieged elephants may increase the destructive impacts of over-browsing on local vegetation [22], and reduce the effectiveness of forest elephant mediated seed-dispersal [23].
