Elevation and latitude drives structure and tree species composition in Andean forests: Results from a large-scale...

Area of Science:

• Ecology
• Botany
• Forest Science

Background:

• Regional-scale knowledge of Andean forest structure and function is limited, with significant geographical gaps in continental and global studies.
• The tropical and subtropical Andes are particularly underrepresented in large-scale forest research.

Purpose of the Study:

• To assess patterns of tree structure and species diversity across extensive latitudinal and elevational gradients in Andean forests.
• To identify key drivers influencing forest composition and diversity across the region.

Main Methods:

• Utilized the Andean Forest Network (Red de Bosques Andinos) database comprising 491 forest plots.
• Analyzed data from 86,964 identified tree stems (≥ 10 cm diameter at breast height) representing 2341 species.
• Examined relationships between elevation, latitude, plot size, and forest characteristics like stem density, basal area, and species richness.

Main Results:

• Tree stem density and basal area increase with elevation, while species richness decreases.
• Both stem density and species richness decrease with increasing latitude.
• Subtropical Andean forests exhibit distinct tree species composition compared to tropical forests, with lower floristic similarity within each region.

Conclusions:

• Forest plots of approximately 0.5 hectares or larger are recommended for accurately describing regional-scale patterns, minimizing plot size effects.
• Promoting collaboration and capacity building (South-South cooperation) among Andean researchers is crucial for generating and synthesizing regional-scale forest information.