Drought, Food, and Trees

October 28, 2015

As we consider the challenges that global climate change poses for food security, it is insightful to look at past episodes of food insecurity for possible solutions that can be adapted to current situations or for any mistakes made and lessons learned. Historically, one of the major causes of food insecurity has been crop failure due to lack of rainfall. In some regions, droughts are infrequent and/or short and less severe while, other regions are more drought-prone in both number and severity. The steppes of Russia are one region known for the frequency and severity of drought conditions that often resulted in extensive famine and human suffering. It was another drought-induced crop failure that led to important developments for agroforestry.

In response to yet another drought and subsequent famine in 1891 that affected over 30 million people, a scientific expedition was dispatched to the drought-stricken region of Russia. The objective given to the expedition team was that of alleviating drought conditions and reducing the risk of future famines. The leader of the 39-member expedition was Vasily V. Dokuchaev, a renowned geographer who was highly regarded within the Russian scientific community. Dokuchaev observed that precipitation in much of the steppe region was marginal for small grain production and naturally inconsistent. If the essential summer rains failed to come or sukhoveys (“thirsty winds”) blew in from more arid regions to the southeast, complete crop failure was often the result.

Dokuchaev quickly designed a plan to address drought alleviation that focused on maximizing the capture and storage of precipitation to be used for crop growth. In addition to using small dams and other practices to reduce runoff, targeting land use based on soil conditions, and enhancing crop selection, he also encouraged the planting of tree windbreaks. The windbreaks were designed to conserve moisture by reducing heat stress, providing physical protection from the sukhoveys, and capturing snow in winter that would melt and become available for crop growth in the spring. By 1900, over 130,000 hectares of windbreaks had been planted and the practice continued to expand throughout the region in the 20^th century.

In the 1930’s, it was the U.S. Great Plains in the grip of a prolonged drought that again resulted in decisive action by a national government. The Prairie States Forestry Project (PSFP) was developed and managed by the U.S. Forest Service to control wind erosion and alleviate drought conditions in six plains states. In 1935, “Possibilities of Shelterbelt Planting in the Plains Region” was published as a comprehensive feasibility analysis for tree windbreak planting across the drought-affected areas. Over the next 7 years 217 million trees were planted in 30,000 km of windbreaks from the state of Texas to the Canadian border in the largest single afforestation project in U.S. history. One of the key figures behind the planning and implementation of the PSFP was a forester named Raphael Zon. Zon was born in Russia in 1874 and was familiar with the work of Dokuchaev and windbreaks on the Russian steppes. It was the demonstrated success of the extensive windbreak planting in Russian, which studies have shown increased crop yields by an average of 15% that led Zon to champion a similar strategy for the drought-stricken U.S. Great Plains.

Dokuchaev’s role in encouraging the establishment of tree windbreaks to modify the local microclimate in not well-known. However, he is widely-recognized as the founder of modern soil science. His 1883 publication “Russian Chernozem” is considered a seminal contribution to the science of soils. He developed the characterization of soils as embodying the unique influences of 5 soil-forming factors: time, parent material, topography, organisms, and climate. The focus on interaction among the 5 factors embodies the ecosystem perspective that is needed for effective land management. A comprehensive ecosystems perspective is essential as we develop climate change mitigation and adaptation strategies in the 21^st century. We can use the efforts of Dokuchaev and Zon as examples for successful project development relying on science-based and comprehensive research, planning, and implementation.