A ten year study published and commented on in Nature concludes that farmers and land resource managers should not rely on seemingly stable but vulnerable single-crop mono-cultures but should encourage more plant diversity on all forms of managed lands; in forests and agro-systems, to help buffer against sudden ecosystem disturbance.
The paper provides evidence from a relatively long-term, controlled study on managed grassland in Pacific North-West America which had been degraded by human management activities over time, particularly as a result of fire prevention measures. While the human-managed grassland remained productive it became very vulnerable to rapid collapse when environmental circumstances changed, with only remnant sections of older bio-diverse grassland being able to resist the reintroduction of fire. The work highlighted the ‘hidden’ value of the more species rich grassland community and the wider case that more bio-diverse environments increase environmental resilience to rapid changes such as flood, drought and fire. “Species are more important than we think,” said MacDougall the principal author, “We need to protect biodiversity.”