Bird extirpations and community dynamics in an Andean cloud forest over 100 years of land-use change.

Long-term studies to understand biodiversity changes remain scarce-especially so for tropical mountains. We examined changes from 1911 to 2016 in the bird community of the cloud forest of San Antonio, a mountain ridge in the Colombian Andes. We evaluated the effects of past land-use change and assessed species vulnerability to climate disruption.

A critique of the 'novel ecosystem' concept.

The 'novel ecosystem' concept has captured the attention of scientists, managers, and science journalists, and more recently of policymakers, before it has been subjected to the scrutiny and empirical validation inherent to science. Lack of rigorous scrutiny can lead to undesirable outcomes in ecosystem management, environmental law, and policy. Contrary to the contentions of its proponents, no explicit, irreversible ecological thresholds allow distinctions between 'novel ecosystems' and 'hybrid' or 'historic' ones.

Effects of patch size and type of coffee matrix on ithomiine butterfly diversity and dispersal in cloud-forest fragments.

Determining the permeability of different types of landscape matrices to animal movement is essential for conserving populations in fragmented landscapes. We evaluated the effects of habitat patch size and matrix type on diversity, isolation, and dispersal of ithomiine butterflies in forest fragments surrounded by coffee agroecosystems in the Colombian Andes. Because ithomiines prefer a shaded understory, we expected the highest diversity and abundance in large fragments surrounded by shade coffee and the lowest in small fragments surrounded by sun coffee.

Spatial components of bird diversity in the Andes of Colombia: implications for designing a regional reserve system.

Beta diversity, or the turnover in species composition among sampling sites in a region, is an important criterion for obtaining adequate representation of regional biodiversity in systems of protected areas. Recently, the additive model for partitioning regional (gamma) diversity (in opposition to the multiplicative model) has been proposed because it allows a direct measure of the contribution of beta diversity to gamma diversity. We determined avian beta diversity along latitudinal (among neighboring river drainages) and elevational axes in a 1347-km2 region on the western slope of the Central Cordillera of the Colombian Andes, where a regional system of protected areas is being designed.