Tag Archives: Forest Transition Theory

Forest decline in the eastern U.S.?

Covering much of central New York State is a mosaic of forest, pasture, and cornfields punctuated by lakes, small towns, rural residences, and sometimes wind turbines (© Peter Klepeis)

Covering much of central New York State is a mosaic of forest, pasture, and cornfields punctuated by lakes, small towns, rural residences, and sometimes wind turbines (© Peter Klepeis)

by Peter Klepeis

Most news coverage of forests tends to focus on deforestation. And for good reason. The Food and Agricultural Organization concludes that from 2000-2010 upwards of 13 million ha of forest per year were converted to other uses or lost to natural causes. Most of the clearing occurs in the tropics, and the resultant biodiversity loss, carbon dioxide emissions, and threats to local inhabitants are among the reasons to be concerned.

Global trends in forest cover hide regional differences, however. Many temperate and rich-country contexts have been experiencing forest recovery for decades. In the eastern United States, for example, cleared areas reached their peak in the mid-to-late 19th century, but this was followed by widespread natural forest regeneration. This forest expansion is celebrated for increasing carbon sequestration and improving water quality, reducing flood risk, decreasing soil erosion, expanding wildlife habitat, and providing opportunities for recreation and extractive industries. But it is not entirely positive. As described in Jim Sterba’s new book Nature Wars, extensive forest cover, a decline in hunters, and a lack of natural predators has led to a boom in wildlife – and deer in particular – with tick-bearing disease, auto accidents, and munched veggie gardens among the negative consequences.

Regardless of its positive or negative impacts on nature and society, what explains the shift from net forest loss to net gain? In the early 1990s the geographer Alexander Mather started to develop forest transition theory: economic development, the abandonment of lands marginal to agriculture, and the movement of rural inhabitants to urban areas tend to stimulate forest recovery. The theory captures fairly well the recovery trends seen in the U.S. and Europe over the past few hundred years. But the theory is not without its critics. Forest change is dynamic, non-linear, and the factors involved are linked to specific places and time periods. Not surprisingly, therefore, recent scholarship documents how – after decades of net gain – forest cover in the eastern U.S. started to decline in the 1970s.

In a new article in the journal Area, my co-authors and I use aerial photographs to evaluate changing forest cover between 1936 and 2008 for a town in central New York State. As expected, a decline in the farming sector and changing life and livelihood goals within farming families led to 25.8 % of the town reforesting. Two new trends emerge, however. First, there is a pronounced increase in the percentage of forest recovering on prime agricultural soils, which holds the potential to diversify habitat and increase biodiversity. Prior to 1994, reforestation on high quality soils was rare. Second, alternative land uses and invasive species, such as the Emerald Ash Borer (Agrilus planipennis), represent possible new forms of forest disturbance. Landowners are starting to develop wind power and natural gas, and practice silviculture. Also, there is steady growth in amenity-oriented land use and rural residential development. These new dynamics challenge theories of forest change, and raise questions about the prospects of sustainable land and forest use in the region.

The author: Peter Klepeis is Associate Professor of Geography at Colgate University, N.Y., U.S.

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Klepeis P, Scull P, LaLonde T, Svajlenka N and Gill N 2013 Changing forest recovery dynamics in the northeastern United States Area DOI: 10.1111/area.12016

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Mather A S and Needle C L 1998 The forest transition: a theoretical basis Area 30 117-24

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Grainger A 1995 The forest transition: an alternative approach Area 27 242-51

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Mather A S 1992 The forest transition Area 24 367-79

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Sterba J 2012 America gone wild Wall Street Journal 2 November

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Food and Agriculture Organization of the United Nations 2012 State of the world’s forests FAO, Rome

Economic growth is no cure for environmental degradation

I-Hsien Porter

Contrary to the perception of economic activities as polluting and environmentally degrading, Forest Transition Theory (Mansfield et al. 2010) suggests that economic growth may promote environmental recovery. More economically developed countries are more likely to have the financial and technological resources and social motivation to conserve the natural environment. This is supported by figures from the Forestry Commission, which show a 3.5% (95,000 ha) increase in woodland areas in the UK over the past decade.

However, in a recent Geography Compass paper, Mansfield et al. argue that economic development does not cause forest regrowth. Rather, forest regrowth reflects a country’s ability to import forest and agricultural products. The degradation caused by the production of those materials is thus exported elsewhere.

In a recent commentary in the Guardian, Friends of the Earth executive director Andy Atkins gave one example. The UK’s imports animal feed for meat and dairy products. This results in land clearance, particularly in Latin American countries, in order to grow the feed. Forest regrowth in the UK is thus partly reliant on deforestation elsewhere. As Mansfield et al. (2010) argue, environmental recovery and economic growth are themselves due to differences and relationships with other places. This adds additional complexity to how we monitor linkages between economic and environmental change.

Mansfield et al. (2010) ‘Does Economic Growth Cause Environmental Recovery? Geographical Explanations For Forest Regrowth.’ Geography Compass 4 (5): 416-427

Andy Atkins, The Guardian, 12th May 2010, ‘Coalition government: Could blue plus yellow equal green?

Forestry Commission: Forestry Statistics 2009