Tree-to-tree interactions slow down Himalayan treeline shifts as inferred from tree spatial patterns

Aim: The spatial patterns of tree populations reflect multiple ecological processes. However, little is known whether these patterns mediate responses to climate in marginal tree populations as those forming alpine treelines. Harsh conditions at these ecotones imply the existence of positive interactions which should lead to tree clustering. In fact, densification in response to climate warming is more widely reported than upward shifts in most treelines. This suggests that more intense tree-to-tree interactions could buffer the treeline responses to climate warming, resulting in low treeline shift rates.

Location: Central Himalayas.

Methods: We examined influence of tree-to-tree interactions on the responsiveness of treelines to climate warming by analyzing a network of 17 treeline sites located across the central Himalayas, and encompassing a wide longitudinal gradient characterized by increasing precipitation eastwards. We quantified the changes in density and the spatial patt...