What is preventing oak forest regeneration in human-modified landscapes? Evidence from a multi-site experiment in central Mexico

Authors:
David Douterlungne

Publication Date:
2019

Abstract/Summary:
Oak forests are climax forest states with an elevated associated biodiversity and complex ecological interactions, and they provide a wide range of ecological services and goods. In spite of their importance, deforestation and expanding agricultural frontiers threaten oak forests worldwide. In México alone – where one third of the world’s oak species grow – more than 20% of its oak forests were lost in the last 50 years while the remaining forests are often heavily impacted by human activities. Seedling establishment in these landscapes is often hampered by a lack of seed-dispersers and harsh micro-environmental conditions. As a result, current regeneration rates are often insufficient to replace older individuals. We set up a field experiment in semi-arid Central Mexico to asses oak regeneration in a human-modified oak forest. We sowed over 8,000 acorns of eight different species in 130 experimental units distributed over five sites (eroded landslides, abandoned cattle pasture, and forest relicts). We tested the impact of five different ecological barriers on seedling establishment: compaction, full sun exposure, enhanced seed predation, poor soil, and absence of litter. We also tested the effectiveness of restoration interventions to overcome these barriers, such as artificial shade or soil transference. Particular barriers or restoration interventions had varying effects according to species, life stage, and site. Furthermore, artificial shade and top-soil transference promoted seedling establishment individually, but not when applied in combination. Our results shed light on oak forest succession in human-modified forests and provide a practical restoration guide to enhance oak seedling establishment.

Resource Type:
Audio/Video, Conference Presentation, SER2019

Pre-approved for CECs under SER's CERP program

Source:
Society for Ecological Restoration