Many countries have started ambitious tree planting programs to recognize the benefits of forests to mitigate climate change by sequestering carbon to support rural livelihoods. Restoration ecologists caution us, however, that planting trees is not always the same as restoring a forest. India has been continuously committed to planting trees on a large scale for the past 50 years, but few studies have evaluated the program’s effectiveness. Coleman et al. evaluate tree plantations in the Kangra District of the Himachal Pradesh state in India, a region with a long history of tree planting and effective cooperation between communities and local governments on forest management and other issues.

Coleman et al. take a mixed method approach, reflecting their interest in ecological and social effects of tree planting programs. They analyze NASA Landsat aerial imagery of hundreds of plantations in the Kangra District recorded over 27 years to investigate ecological changes over time. Forest Service of India data also supports the analysis. Measuring the tree canopy density change tells them how much the tree planting has helped reforest an area. Change in the percentage of broadleaf forest cover in the plantations, compared with needleleaf forest or grasslands, suggests whether the area has become more beneficial to the local community. The region’s households tend to prefer forests with broadleaf trees because they offer better firewood and animal fodder. For more detail on the usefulness of the tree planting programs, the researchers also present the results of surveys of households near each plantation.

Despite the long history of state-sponsored tree planting in the Kangra District, Coleman et al. find little effect on reforestation or benefit to the local community. Older plantations do not have significantly more tree canopy density than newer ones. Needleleaf species, rather than the preferred broadleaf ones, have increased on plantations. While almost half of the households surveyed use the plantations to some degree, few have come to rely on them for fuel, fodder, or grazing land.

The Kangra District may be home to such ineffective tree planting programs because many plantations were located in areas already somewhat forested to begin with. The district is a densely settled, productive agricultural area, so converting farmland back to the forest would face socioeconomic and ecological obstacles. Though the local context makes it hard to generalize their results, Coleman et al. stress the need to critically reevaluate the strategy of planting trees to restore valuable and carbon sequestering forests at a national and international scale.

This post is a summary of Coleman et al.’s recent piece, summarized by COSSPP blog researcher, Jesse Fried.