Remnant trees and the conservation of biodiversity in Costa Rican pastures

摘要: Remnant trees may play an important role in conserving biodiversity within agricultural systems because they provide habitats and resources that are otherwise absent from landscapes. In order to determine the potential importance of remnant for conservation, we surveyed density species composition occurring pastures 24 dairy farms near Monteverde, Costa Rica. addition, conducted interviews with farmers why leave how manage them. our survey 237 ha pastures, counted 5583 190 (mean 25 trees/ha). Primary forest accounted 57% all 33% tree individuals. Over 90% known food birds other animals. many locally humans as sources timber (37%), firewood (36%) or fence posts (20%). Farmers mentioned 19 reasons leaving pastures. Of these, shade cattle, timber, fruits were most commonly cited. Most well aware both economic ecological benefits pasture trees, interested possibility increasing cover their Although current densities richness Monteverde high, size distribution indicates diversity will decrease substantially future years, harvesting saplings primary scarce