It takes 200-400 years to form one centimeter of soil, while the estimated rate of soil erosion is 100 times greater than soil formation. Where erosion is prevalent, the rate of soil loss reaches 4 mm per year (FAO 2015); 70% of drylands suffer from land degradation in varying degrees (Gibbs and Salmon 2015). While global population grows rapidly, land is finite in quantity.

With an annual financial loss of US$400 billion due to soil erosion from arable lands, as estimated by the FAO-led Global Soil Partnership, investing in sustainable land management and practices such as restoring degraded land can recover soil health and enhance soil functions and land productivity to provide critical ecological and economic benefits for human needs. Goal 15 of the UN Sustainable Development Goals (SDGs) explicitly outlines the international community’s resolve to halt and reverse land degradation.

In addition to protecting land against desertification, forests can regulate water, sequester carbon, and supply timber and other forest products. Forests are thus a central interest of governmental investments for multi-purpose land restoration. The FAO’s Global Forest Resources Assessment 2015 showed that investments in restoring land led to a significant increase of plantation forests by over 105 million hectares since 1990.

Do man-made forests increase environmental and social resilience and offset the negative impacts of global change (Goal 13)?

Our recent study demonstrates that the co-benefits from plantation forests significantly depend on forest management (Schwärzel et al. 2018). Forest structure and management are vital for partitioning of the water budget and regulating water supply.

While man-made forestlands remove more water from soil to atmosphere through evapotranspiration, they tend to reduce groundwater recharge and water availability for downstream users. This is a particularly critical issue for transboundary regions and areas that already suffer from global warming and water scarcity, as it aggravates social and political instability, poverty, conflict, and migration.

Therefore, we must manage plantation forests to realize a range of ecological and economic gains for a cost-effective investment. The variety and composition of co-benefits will be mainly determined by land use decisions on how to minimize trade-offs and create synergies between various ecosystem services that are needed for local conditions.

Is the application of forest management sufficient to ensure a cost-effective investment for achieving a desirable multifunctional land-use system?

Land restoration policies that are based on non-participatory processes and “one-size-fits-all” measures have a high possibility of not being accepted by relevant stakeholders and compromising ecological and socioeconomic gains. They can eventually result in an investment in vain (Zhang and Schwärzel 2017).

To avoid such a situation, three core issues in land restoration decision-making should be taken into account: (i) maintain land resources and enhance ecological functions, (ii) generate short-term income for land users, and (iii) ensure long-term political goals for sustainable development. Achieving these three aims simultaneously will need policy recognition of the interrelation across sectors and of the equal importance of long-term ecological and short-term economic gains. Investment in land restoration that includes incentives for participants is likely to guarantee long-term success. For example, the inclusion of economic benefits for farmers to manage plantation forests for producing more water can improve the sustainability of afforestation in land restoration.

Wise investments that maintain the desired co-benefits at low cost are needed to restore land

We suggest investing in critical linkages that are closely linked to several problems.

Soil conservation is one of such critical linkages because intact soils support crop growth, recycle nutrients, mitigate greenhouse gas emission, increase the residence time of carbon in land-based ecosystems, and serve as an intermediary of major hydrological processes determining water quality and availability, such as water purification, groundwater recharge, and flood and sediment alleviation. Investment in soil conservation practices improves simultaneously multiple ecosystem services for local and downstream users, as well as rural and urban population, including food and water security, climate mitigation, and poverty alleviation (Zhang and Schwärzel 2017).

For this reason, it is more efficient to finance critical linkages, since they are often the point of departure for increasing synergies, thus the points for policy and financial intervention.

Exploring new approaches to invest in combating land degradation

Engaging the private sector in restoring land activities is not on many countries’ agendas to combat land degradation. But there is great potential in the role of the private sector. Farmers and foresters should be paid if they manage their land in such a way that they increase environmental flow to the downstream, reduce soil erosion including the transport of nutrients and herbicides to water bodies, and increase groundwater recharge and water purification. Such management saves the private sector’s cost for water diversion, reallocation and treatment. We need to explore new approaches to leverage finances for wise investments in land (Goal 17). A good example is the first global private sector fund (known as the Land Degradation Neutrality Fund) announced at the 13th session of the Conference of the Parties to the UN Convention to Combat Desertification (UNCCD COP 13).

However, misuse of investment should be avoided. For example, the private sector can make a profit and contribute to land restoration by establishing even-aged pure fast-growing tree species on degraded land. Yet, the establishment of such monoculture plantations may introduce high risks of pests and diseases, while the fast growth of trees makes the water table shallower and dries out water sources due to the feature of “water pump.” In such cases, use of funding from the private sector would essentially give investors the right to make other environmental damages.

While acknowledging the new opportunities, we must be aware that the participation of the private sector may introduce additional risks. Enabling policies and legal frameworks should be created to regulate a mode of “economy and environment” in the private sector in their efforts to combat land degradation. Moreover, their actions should be based on sound scientific evidence and knowledge, as well as give full consideration of the needs of stakeholders.

In summary, the natural capital of soil/land is underestimated and sometimes neglected. Smart investments in combating land degradation must address emerging ecological issues and socioeconomic demands in a local or regional context. Experiences and results of studies around the world will provide valuable lessons and knowledge that will help us build towards more sustainable land restoration. Land has its true value; investments come from many sectors and can take many forms – so we have to make wise choices to best invest in it.

References

Borrelli, P. et al. 2017. “An assessment of the global impact of 21st century land use change on soil erosion.” Nature Communication 8: 2013.

FAO, 2015. Status of the World’s Soil Resources. ISBN: 978-92-5-109004-6, pp 650. (http://www.fao.org/documents/card/en/c/c6814873-efc3-41db-b7d3-2081a10ede50/)

Gibbs, H.K. and Salmon, J.M. 2015. “Mapping the world’s degraded lands.” Applied Geography, 57:12–21.

Schwärzel, K. et al. 2018. “Improved Water Consumption Estimates of Black Locust Plantations in China’s Loess Plateau.” Forests 9(4):1–21.

Zhang, L. and Schwärzel, K. 2017. “China’s Land Resources Dilemma: Problems, Outcomes, and Options for Sustainable Land Restoration.” Sustainability 9(12):1–13.

Zhang, L. and Schwärzel, K. (ed.) 2017. Multifunctional Land-Use Systems for Managing the Nexus of Environmental Resources, Cham: Springer International Publishing. ISBN: 9783319549569, pp 148.