Conserving and promoting evenness: organic farming and fire-based wildland management as case studies

A biodiverse ecosystem is classified by having high species richness, and high species evenness.  Species richness is the number of species and species evenness is the relative abundance of species.  The goal of this study was to examine the benefits to biodiversity from the use of two different land management schemes.

These two different strategies were organic farming practices and the controlled burning of land.  Rather then run lengthy and expensive experiments Crowder et. al searched for old studies of organic vs. conventional farming and burned vs. unburned conservation sites. They found 173 studies comparing organic vs. conventional farming.  These studies included a lot of variety, spanning 23 countries and 38 crops.  They also found 155 studies of burned vs. unburned conservation sites spanning 21 countries. 

Analysis of the studies showed both strategies significantly increased species richness and evenness.  The results also span many taxa showing these conservation practices work for many different types of organisms.  These results support organic farming and controlled burning as viable strategies for increasing ecosystem biodiversity.  The study also provided evidence that species richness and evenness are not correlated.  This shows that species richness and evenness are different aspects of biodiversity and should be addressed separately during conservation efforts.

http://www.esajournals.org/doi/pdf/10.1890/12-0110.1

Crowder, David W., Tobin D. Northfield, Richard Gomulkiewicz, and William E. Snyder. 2012. Conserving and promoting evenness: organic farming and fire-based wildland management as case studies. Ecology 93:2001–2007.

-Jimmy Peniston