Miombo Woodlands: A Key Ecosystem in Securing the Resilience of People of Southern Africa

Assistant Professor of Environmental Sciences Natasha S. Ribeiro explains the importance of the immense ecosystem in the Miombo Woodlands in Southern Africa, which span seven countries and is home to orchids, elephants, and 200,000 years of ancestors.

Miombo woodlands of southern Africa are part of the tropical dry forest ecosystems, spanning about 2 million km2 in seven countries (from southeast to northwest, Mozambique, Tanzania, Malawi, Zimbabwe, Zambia, Democratic Republic of Congo, and Angola). The woodlands are largely known for their plant diversity of about 8500 species of trees, grasses, orchids, aloes, and high levels of endemism. The miombo woodlands typically comprise an upper canopy of umbrella-shaped trees largely dominated by the genera Julbernardia, Brachystegia, and Isoberlinia. Their vernacular name in Kishawili - miombo – it’s where the ecosystem gets its name. The woodlands are immersed in a diverse landscape of seasonally flooded islands of grasslands (called dambos), riverine forests, granitic mountains also known as inselbergs (some vegetated with grasslands and/or evergreen forests and some bare rock or with scarce vegetation), underground forests (Geoxylic suffrutices) and termite mounds. (Figure 1)

Figure 1: The Varied Landscapes in Miombo:  upper left: a Dambo (photo credit: N. Ribeiro); upper right: Underground Forests (photo credit: F. Gonçalves); bottom left: Open Miombo (photo credits: N. Ribeiro); bottom right: Overview of Miombo Woodlands (photo credits: N Ribeiro)

This diversity of habitats confers the miombo a large diversity of wildlife species; it is the last remnant of some important megafauna species such as elephants, buffalos, lions. Miombo is a seasonal ecosystem with 5-8 dry months (April/May to October/November) when precipitation is less than 500 mm followed by a rainy season with 1000- > 1200 mm of rainfall. This seasonality decreases towards the central and northwest side of its range, in Zambia, Angola, and Democratic Republic of Congo, where it is known as wet miombo. The seasonality brings to the region varied landscape scenes throughout the year, from green forest cover (between December and June), a dry leafless and burned landscape (between July and October), and a reddish fall-like landscape previous to the onset of the rainy season when tree species shed the first leaves, between October and December. (Figure 2)

Figure 2: The Different Seasons in Miombo: top left: end of the dry season (photo credit: N. Ribeiro); top right: onset of the rainy season (photo credit: Bioversity International); and bottom left: end of the rainy season (photo credit: N. Ribeiro) 

So, visiting the same area of miombo during different times of the year could give visitors, divergent perceptions about the woodlands, from degraded woodlands in the peak of the dry season to an impressive green tree and grass cover after the rains. A part of the climate the woodlands are shaped by disturbances such as swidden agriculture, fires, and herbivory essentially by elephants. These are important landscape drivers that have shaped the woodlands over centuries and thus cannot be dissociated from miombo ecology.

One cannot address the miombo woodlands without thinking about the people who have been living in and from the woodlands for more than 200,000 years as reported in many archeological sites across the region. In fact, miombo is commonly called a “social ecosystem” given the myriad of goods and services it provides for over 70% of the population and supports rural and national economies. (Figure 3)

Figure 3: Some of the Services Provided by Miombo Woodlands: top left: Land for Agriculture (photo credit: Niassa Special Reserve); top right: Carbon Storage (photo credit: Niassa Special Reserve); bottom left: Beehives (photo credit: Bioversity International); bottom right: Charcoal (photo credit: Bioversity International). 

In turn, the ecology of the woodlands has been shaped by human activities. The many provisioning services provided by the woodlands include a diversity of foods: mushrooms, fruits, roots, leaves to mention a few, medicinal plants which also have a cultural attachment in the form of taboos among others, building materials: tach grass, poles, beehives, hennery, etc., energy in the form of charcoal, among others. Timber for exportation represents the main income source for national economies. The woodlands are also very important culturally, as a place to venerate the ancestors and as family cemeteries. Regulating services are also very important and span from water, air and soil regulation, and pollination, but most of these services are still barely understood in miombo. However, it is now understood that miombo woodlands have the capacity to sequester 18-24 PgC, similar to their tropical counterparts, showing their capacity to mitigate the effects of climate change.

Despite their socio-ecological importance, the woodlands are at risk associated with a combination of several direct and underlying causes. The woodlands cover some of the world’s poorest countries and the human population is increasing at a fast pace of about 2.7% a year. Leveraging these economies in a changing world, implies developing different sectors of their economies including infrastructures, mining, and agriculture. This has resulted in the conversion and/or degradation of this key ecosystem. A loss of about 1/3 of miombo cover in the last 10-15 years was recently estimated (Dziba et al., 2020). The reduced miombo cover is already affecting its capacity to provide goods and services with implications for the social structure and biodiversity conservation. However, there is hope for the miombo woodlands, and the book by Ribeiro et al. (2020) Miombo Woodlands in a Changing Environment: Securing the Resilience and Sustainability of People and Woodlands brings important insights into how miombo can be saved. In summary, there is a need to:

1. Make the economic case for miombo, by developing a variety of nature-based solutions.
2. Develop new and cutting-edge technologies and new strategies for miombo management.
3. Change in forest management paradigms to adapt to the local/regional context of the diversity of products offered by the woodlands.
4. Develop and implement ecosystem restoration strategies shaped to ecosystem resilience.
5. Improve governance systems by promoting bottom-up approaches, by which rural communities have a stronger voice and power to make decisions and fight against corruption.
6. Continued research to continue understanding of the ecosystem in a changing world and especially the use of research outputs to support decisions.