Finding Sustainability in Ecosystem Restoration

The Causes of Degradation

In the Loess Plateau, a multiyear study was implemented in the early 1990s in order to determine what was causing the consistent degradation. The negative factors that caused the vegetation to be lost were identified as tree cutting, farming on steep slopes and free ranging of goats and sheep. All of these negative behaviors were eventually banned. While understanding how ecosystems become dysfunctional is extremely important and somewhat satisfying, in order to get a different outcome on the Loess Plateau it was necessary to have a complete change in people’s behavior. Although many people assume that in China, governed by the Chinese Communist Party, the government could just order the people to give up their traditional behaviors; this was not the case. A massive public education campaign using the well-tested Participatory Rural Assessment (PRA) was employed to engage the population in the inquiry. This meant that the people could understand not only what the government was asking them to do but why. Geographical Information Systems (GIS) was also employed providing satellite images to map every watershed on the plateau. In this way a unique address could be assigned to even the smallest watercourse. Enterprise software that reflected every investment and every intervention was also used to track changes throughout the management chain.

The Problem: Productivity Valued over Ecosystem Function

Once the basic historical mistakes that needed to be addressed were identified, a plan was developed and several physical interventions were envisioned. This began by making an econometric evaluation of profound importance. The Chinese recognized that the ecologic function that was being lost was vastly more valuable than the productivity that was being extracted from the plateau. This allowed them to make a huge breakthrough that is leading to several non-linear and somewhat counter-intuitive outcomes. Because they determined that the ecosystem value was higher than the productive value, it made sense to designate much of the land as ecological land rather than economic land. This measure alone is a giant step forward in ensuring that biodiversity will survive into future generations. This step also concentrated the agricultural development in smaller areas where there could be focused investment and improvement. Although basically a mapping exercise it provided a strong tool to show everyone what was being contemplated and what was at stake. Since the project area was 35,000 sq kilometers the work reached a scale that went far beyond individual or even community production and income and reached landscape or ecological scales.

“By bringing scientists, technicians and managers into the local communities the Chinese essentially helped transition poor, often illiterate subsistence agriculturalists to a new paradigm within one generation.”

The Dynamics of Rainfall

One of the most fascinating things that I have learned on this journey is about the dynamics of rainfall and the role of the canopy, undergrowth and organic matter in regulating the natural water cycle. For the restoration of the Loess Plateau, the next step was an engineering feat. Due to the massive impact that centuries and millennia of poor agricultural practices had had it was necessary to first ensure that all the rain was infiltrated and retained where it fell down. The plateau, like many other parts of the world, receives water at specific times of the year. These rainy seasons in this part of the world are monsoonal and depend on rainfall coming out of the Himalayan Mountains. These rain patterns have been relatively consistent and should have given a clue to ancient peoples what was happening to them. But because of the slow pace of change that might have been happening over generations they failed to see that, although the rainfall was not changing that much, the infiltration, retention and evaporation was changing at a far greater pace. The answer was a series of engineering works such as sediment traps and check dams, all designed to slow the runoff, to infiltrate and to hold the water within the system. In the very beginning this was a physical intervention, but it quickly became a biophysical intervention as permanent vegetation grew up in both the ecological and the economic lands.

Differentiation Between Ecological and Economic Land

The Chinese determined that although the value of the ecological function was higher than the value of the production, the people still needed to eat, to feed their livestock and to make some money by selling things on the local, regional and global economy. Having already banned slope farming, they were limited in how much land could be used for agriculture. In order to maximize the area available for farming they decided to terrace the hillsides. If they could make the fields flat then they would be useful for farming without the enormous erosion caused by the slope farming. If they could not be terraced then the land would by necessity fall into the ecological land category and the people would not be allowed to farm it. This was a second massive engineering task and it was achieved by hiring the people to engage in the activity. This meant that the people gained in three ways. They were earning money, they were learning new sustainable agricultural methods and they would eventually own the outputs that came from the fields.

Worldwide Recognition of Land Rehabilitation

Over the years of following the rehabilitation of the Loess Plateau I have witnessed the land change from a fundamentally degraded system into a system that is stimulating the growth of vast amounts of biomass, accumulating organic matter in the soil, protecting and creating new habitat for biodiversity and naturally infiltrating and retaining rainfall. The results have exceeded even the designer’s expectations and have shown that it is possible to rehabilitate large-scale damaged ecosystems. By bringing scientists, technicians and managers into the local communities the Chinese essentially helped transition poor, often illiterate subsistence agriculturalists to a new paradigm within one generation. Seeing and documenting the restoration of the Loess Plateau has been a source of inspiration and purpose but also a huge responsibility. When I began to realize how important the developments I was witnessing were, I began to speak publicly about it.