About LUISA
Welcome to the information pages of “Land Use Intensity’s Potential, Vulnerability and Resilience for Sustainable Agriculture in Africa” (LUISA) project, which was run for ESA from 2023 to 2026. The work extended across diverse African landscapes, aiming to capture the varied challenges and opportunities present in Africa’s agricultural sector. It was run in partnership with esteemed institutions and organizations both locally and internationally
About HANPP
Central to the project is the concept of Human Appropriation of Net Primary Productivity (HANPP), a crucial environmental indicator. Net primary production (NPP) is the net amount of biomass produced by plants each year and a key ecosystem process providing the basic sustenance for all heterotrophs. Humans interfere with this process by transforming ecosystems in terms of land cover change, e.g. converting forests to croplands, and by extracting biomass to provide societies with food, animal feed, fiber or bioenergy. The framework of HANPP quantifies these alterations of NPP flows and hence the availability of trophic energy in ecosystems across land-use types and attributes them to various land-use processes and primary biomass products. This allows to assess and compare land-use intensities and resulting pressures on ecosystems across space and time.
Through the utilisation of advanced technologies such as remote sensing and dynamic global vegetation models (DGVMs), the primary objective of the project was to facilitate decision-makers’ understanding of the drivers and consequences of land use intensification on carbon dynamics.
Methodology
Motivation
Africa is undergoing major social and environmental changes that are expected to reshape where and how land is used—for farming, grazing, forests, and cities (Molotoks et al., 2018). These changes will have significant consequences for the global carbon cycle. Africa's population is growing faster than anywhere else in the world (UN, 2022), and by 2050, the continent is projected to account for 65% of global population growth. At the same time, atmospheric carbon dioxide levels and surface temperatures are expected to keep rising (Malhi et al., 2013), and rainfall patterns will become more unpredictable (Wang et al., 2020).
African forests also play a critical role in the planet’s carbon balance, contributing about half of the year-to-year variation in global land-based CO2 emissions (Saatchi et al., 2011). One of the main drivers of carbon emissions on the continent is the gradual spread of small farms into forested areas near cities (Valentini et al., 2014). To better understand these land-use changes and their impact on carbon emissions, scientists use large-scale indicators—like the Human Appropriation of Net Primary Productivity (HANPP)—which help reveal how human activity shapes ecosystems from regional to global levels (Haberl et al., 2014)
HANPP defined and built-up
Humans alter ecosystems through land cover changes, for example by converting forests to croplands, and through the extraction of biomass for food, feed, energy and other uses. The extent of this ecosystem alteration can be evaluated by assessing changes in NPP, i.e. the availability of trophic energy in ecosystems through the framework of Human Appropriation of NPP (HANPP). The HANPP framework consists of various components which can provide different insights into biomass flows (carbon flows) from production to final use in society (see Figure, Tracing NPP flows within the HANPP framework) (Haberl et al., 2014)
The HANPP can be calculated for all land use types, e.g. cropland, grazing land, forests and settlements. This area-specific approach is useful for accounting for HANPP within a defined geographical area, i.e. for domestic production (Haberl et al. 2014).
The HANPP approach can be extended to a consumption-based approach, which allows the HANPP resulting from a product"s production chain or consumption within a defined entity, such as a national economy, to be accounted for (Haberl et al. 2014).
Tracing NPP flows within the HANPP framework.
HANPP calculation
HANPP is calculated by assessing the alteration of NPP and comparing:
- NPPpot: the amount of potential productivity that would prevail in an area without human land use or interference under given climate conditions.
- NPPeco: the productivity that remains in the ecosystem after harvests.
Definition of the HANPP framework demonstrating the different key components. Adapted figure based on Haberl et al. 2014
HANPP land use change vs. HANPP harvested
HANPP can also be calculated as a sum of HANPPharv and HANPPluc:
- HANPPharv: the portion of extracted biomass harvested by humans (e.g. crops, timber..). It considers not only the marketable share of harvests but the total cultivated plant destroyed or extracted during harvest. The used part includes the final product and other used plant materials f.e. Straw or stover. The unused HANPPharv considers harvest losses or unused residues).
- HANPPluc: is the difference between NPPpot and NPPact and denotes productivity losses due to land cover changes, such as changes in NPP resulting from replacing one ecosystem type with another or from land sealing for infrastructure and construction purposes
Considering those two components allows us to evaluate the societal efficiency of land-based production i.e. how much NPP is converted and used within the socio-economic system.
The individual HANPP components enable intensive variables and indicators to be generated. The most relevant of these is the so-called HANPP efficiency ratio. This ratio can be used to assess the proportion of harvested biomass, whether used or extracted, in total HANPP. Land-use systems with low HANPP loss are characterised by higher HANPP efficiency than those with significant productivity losses. High HANPP efficiency is related to a high proportion of the harvested biomass entering the socioeconomic system (Haberl et al. 2014). This further allows analysis of the mechanisms underlying land use transitions, e.g. agricultural intensification or expansion (Gingrich et al., 2015).
NPP actual: Africa’s Green Productivity Map
Net Primary Productivity - actual (NPPact) is how much new plant growth happens each year under real-world conditions (today’s climate, land use, and farming/management). It matters because more growth means more food and biomass, better wildlife habitat, and more carbon taken from the air. A map with average NPPact by African country lets you see which places are more productive (usually wetter, greener regions) and which are less (drier areas). You can compare countries, spot big patterns (rainforests high, deserts low), get a rough sense of farming potential and water stress, and, if you look over time, track changes.
References
- Haberl, H., Erb, K.-H., & Krausmann, F. (2014). Human Appropriation of Net Primary Production: Patterns, Trends, and Planetary Boundaries. Annual Review of Environment and Resources, 39(1), 363–391. DOI
- Haberl, H., Wackernagel, M., Krausmann, F., Erb, K.-H., & Monfreda, C. (2004). Ecological footprints and human appropriation of net primary production: A comparison. Land Use Policy, 21(3), 279–288. DOI
- Gingrich, S., Niedertscheider, M., Kastner, T., Haberl, H., Cosor, G., Krausmann, F., Kuemmerle, T., Müller, D., Reith-Musel, A., Jepsen, M. R., Vadineanu, A., & Erb, K.-H. (2015). Exploring long-term trends in land use change and aboveground human appropriation of net primary production in nine European countries. Land Use Policy, 47, 426–438. DOI
CASE STUDIES AND PRODUCTS
The remote sensing-driven Human Appropriation of Net Primary Productivity (HANPP) monitoring framework resulted in the production of several products:
Those products were developed focussing on several general land cover types in case study agroecosystems representative of the variety of landscape conditions encountered in Africa:
- Ethiopia: Highland region of Lake Tana
- Mozambique: Beira Agricultural Growth Corridor
- Senegal: Silvopastoral area
- Uganda: Mount Elgon Agroforestry Zone
Ethiopia: Highland region of Lake Tana
The Lake Tana basin is the headwaters of the Blue Nile River located in the north-western highlands of Ethiopia
Agriculture is the primary livelihood, which immediately supports the cities of Bahir Dar and Gondar. The area is a typical example of a smallholder highland farming system where farmers operate on highly fragmented fields of < 1ha fields. The agroecosystem traditionally consisted of staple crops such as tef, maize, wheat, mixed with animal production. New cropping systems are emerging, including flooded rice and eucalyptus plantations.
The Lake Tana Basin is a major freshwater resource for crop irrigation, livestock production, and hydroelectric power generation. It is also a silt refinery and biodiversity hotspot for the Blue Nile River. The wetlands of Lake Tana area are an integral part of the lake and play a significant role in sediment retention, flood protection, purification of the landscape, important breeding grounds for birds identified by IUCN as an important bird area.
Comparison of cropping systems
Increased demand for biomass must be met, for example by increasing yields. The HANPP framework enables the monitoring of changes in biomass production over time and space, providing an effective policy-making tool for this ever-changing basin. This case study region therefore focuses on monitoring cropland yields, specifically for maize and rice.
- Productivity can be assessed by monitoring harvest levels in relation to harvest potential as well as the identification of inefficient agricultural plots using the HANPPefficiency ratio (HANPPharv:HANPP)
- The comparison of productivity of different cultivars or crops can be applied using crop specific or cultivar specific HANPPharv estimates
- To evaluate the pressure of cropping on the environment, NPP that remains in the ecosystem after harvest can be monitored, namely NPPeco.
References
Grabher, H. (2021). HANPP trajectories for Ethiopia reveal recent agricultural efficiency gains but high grazing intensity. Environment, Development and Sustainability, 23(4), 5277–5296.DOI
Products
HANPP_HARV_RANGELAND: Human Appropriation of Net Primary Productivity - Rangeland Harvest https://browser.apex.esa.int/external/eoresults.esa.int/stac/collections/ESA_LUISA_HANPP_HARV_RANGELAN
Mozambique: Beira Agricultural Growth Corridor
The district of Nhamatanda encompasses two administrative posts, Nhamatanda-sede and Tica, each exhibiting distinct climatic patterns
The eastern region is classified as tropical rainy savannah climate, while the western region is classified as humid temperate tropical with an average annual rainfall of 1200 mm. The area fosters favorable conditions for agricultural activities because of the soils rich in organic matter and high water retention capacity.
Agriculture serves as the primary economic driver, predominantly conducted under rainfed conditions. Small family farms dot the landscape, engaging in manual cultivation practices, often intercropping varieties such as corn, cassava, mapira, beans, sweet potatoes, sorghum, rice, peanuts, sesame, and soybeans. Large-scale monoculture cultivation of crops like sugarcane and cotton is more common in the administrative post of Tica.
The post of Tica intersects the Beira Corridor (Beira Agricultural Growth Corridor-BAGC), a critical transport route in southern Africa. Consequently, areas traversed by this corridor witness heightened agricultural activity, amplifying the need for sustainable land management practices.
Monitoring agricultural intensification in the Nhamatanda districts
Population growth in the Nhamatanda is driving increased demand for natural resources. Agriculture is characterized by smallholder farms cultivating key global staple crops—such as maize, soybeans, rice, and sorghum—and large commercial operations focused on sugarcane production. Nhamatanda District lies within the Beira Agricultural Growth Corridor, where commercial agricultural activities are expected to expand.
The key elements of the HANPP (Human Appropriation of Net Primary Production) framework can be used to evaluate both the intensity of biomass harvest and the efficiency of resource use:
- HANPPharv and HANPPluc serve as indicators of agricultural expansion. An increase in HANPPharv suggests a higher proportion of biomass is being extracted through cropping activities.
- HANPPluc reflects productivity losses, for example, when farmland expands into woodland areas. Productivity can be evaluated by comparing actual harvest levels to potential yields and identifying underperforming agricultural plots.
- The HANPP efficiency ratio (HANPPharv:HANPP) helps assess how much harvested biomass is obtained relative to the overall productivity loss, offering insight into the efficiency of land use practices.
References
- Fetzel, T., Niedertscheider, M., Haberl, H., Krausmann, F., & Erb, K.-H. (2016). Patterns and changes of land use and land-use efficiency in Africa 1980–2005: An analysis based on the human appropriation of net primary production framework. Regional Environmental Change, 16(5), 1507–1520.DOI
Products
Senegal: Silvopastoral area
Silvopastoral Zone
The silvopastoral zone (SPZ) of Ferlo, Senegal is located in the Sahelian belt and covers an area of about 101,609 km² across five ecoregions: the Agricultural Expansion Region, the Eastern Transition Region, the Ferruginous Pastoral Region, the Northern Sandy Pastoral Region, and the Southern Sandy Pastoral Region.
The main livelihood in the SPZ consists of livestock production and rainfed agriculture. The main crops grown include millet, cowpeas and sorghum. Other sources income are derived from timber and arabic gum extraction, as well as fruit harvesting of Balanites aegyptiaca and Zizyphus mauritiana. These activities are divided into five distinct sub-systems: sylvopastoral, agrosylvopastoral, agropastoral, lower Ferlo valley and peri-urban.
The main type of land cover includes agricultural land, water bodies, wetlands, dry forests, shrublands, pastures and rangelands, urban areas and infrastructure. However, the diversity of land cover types in the SPZ reflects the complex interactions between human activities, natural resources and environmental conditions in the region. This represents a sustainable development challenge specific to the silvopastoral zone. Decades-long pressures from logging, agricultural expansion, overgrazing and other human activities are contributing to the gradual degradation of this region.
Measuring grazing intensity in the Ferlo region
Within the HANPP framework, grazing intensity and the availability of forage resources can be assessed and monitored. This allows for the spatial and temporal analysis of areas where overgrazing may occur, potentially leading to vegetation degradation.
A key indicator for this assessment is the ratio of HANPPharv and NPPact.
- HANPPharv on grazing land reflects the biomass demand through livestock grazing and is calculated based on regional livestock numbers.
- NPPact indicates the amount of herbaceous biomass produced on a given area, and thus the biomass available for grazing.
- The HANPPharv:NPPact ratio provides insight into the pressure exerted on available forage resources in relation to their regenerative capacity. It is important to consider that only a portion of total NPP—namely the herbaceous and foliar biomass—is accessible and digestible for livestock, as opposed to woody biomass. This indicator also enables the comparison of regional feed availability with actual grazing demand, which is determined by livestock densities and prevailing feeding systems.
Implementation of the Great Green Wall
The Great Green Wall (GGW) initiative, launched by the African Union in 2007, aims to combat land degradation and desertification by restoring 100 million hectares of land across the Sahel region. In Senegal, one of the most prominent examples of GGW implementation is found in the Ferlo region—an area characterized by transhumant pastoralism as the dominant land-use system (Diop et al., 2018). However, the introduction of GGW activities has led to significant changes in land cover, including the enclosure of reforested zones, which contributes to the fragmentation of traditional pastoral spaces
The application of the HANPP framework offers valuable insights to better understand the implementation of the GGW initiative:
- The tree cover area and their respective NPPact monitors and localizes the expansion and increasing greenness of the GGW
- HANPPharv can be used to evaluate if harvest activities are affected by the implementation of the GGW, harvest on different plots can be compared, for example mono-cultural agriculture and forest gardens.
- By comparing NPPpot and NPPact it is possible to monitor the potential NPP and the current NPP to detect productivity losses (HANPPluc). This provides a means to evaluate whether the GGW"s ecological restoration goals align with actual improvements in ecosystem productivity
References
- Further references: Erb, K. H., T. Fetzel, T. Kastner, C. Kroisleitner, C. Lauk, A. Mayer, and M. Niedertscheider (2016), Livestock grazing, the neglected land use, in Social Ecology: Society-Nature Relations Across Time And Space, edited by H. Haberl et al., pp. 295–319, Springer, Dordrecht, Netherlands. DOI
- Diop, S., Guisse, A., Sene, C., Cisse, B., Diop, N.R., Ka, S.D., Cisse, A.G., Sambou, S., Ndiaye, O., Fandohan, A.B., Chao, F., Guoqin, W., Yongdong, W., 2018. Combating Desertification and Improving Local Livelihoods through the GGWI in the Sahel Region: The Example of Senegal. J. Resour. Ecol. 9, 257–265.DOI
Products
HANPP_HARV_RANGELAND: Human Appropriation of Net Primary Productivity - Rangeland Harvest https://browser.apex.esa.int/external/eoresults.esa.int/stac/collections/ESA_LUISA_HANPP_HARV_RANGELAND
Uganda: Mount Elgon Agroforestry Zone
Coffee-banana agroecological system
The Bududa District is one of nine districts in the Mount Elgon of Eastern Uganda. Mount Elgon is one of the oldest volcanoes in East Africa. The Bududa District includes the headwaters of the Manafwa catchment. The district has an area of approximately 251 km² and consists of complex topography with altitudes ranging from 1500 to 4139 meters above sea level. The district receives rainfall amounts much higher than other districts in Uganda (annual average rainfall > 1500 mm).
The rainfall and soil conditions are generally supportive of agriculture which is the dominant land use in the area. Agriculture in the area is dominated by smallholder rainfed farms. Bududa District constitutes part of the coffee-banana agroecological system of Uganda. Farmlands consist of crops for domestic consumption and for cash such as banana, cassava, sweet potato, maize, coffee, onions, among others. Up to six crops can be intercropped, reflecting the high productivity of the soil.
The current population in Bududda district is estimated at about 300,000 with high population density of up to 1000 persons/km² vis-à-vis the national average of 160 inhabitants per km² . The annual population growth rate is about 3.6% which surpasses the national rate of 3.0%. Socio-economic pressures make the district prone to landslide and flood hazards often culminating.
Encroachment of agriculture into forests
Declining forest cover and associated deforestation are driven by both commercial and illegal logging, as well as the expansion of land for agriculture. Key components of the HANPP framework can be used to monitor these changes:
Tree cover area and the corresponding NPPact are used to detect and localize reductions in forested areas and their productivity.
HANPPluc serves as an indicator of productivity loss resulting from land cover change. A decline in HANPPluc suggests that a more productive land cover, such as forest, is being replaced by one with lower productivity, such as cropland or degraded land.
References
Kastner, T. (2009). Trajectories in human domination of ecosystems: Human appropriation of net primary production in the Philippines during the 20th century. Ecological Economics, 69(2), 260–269.DOI
Products
HANPP_LUC: Human Appropriation of the Net Primary Production Land Use https://browser.apex.esa.int/external/eoresults.esa.int/stac/collections/ESA_LUISA_HANPP_LUC
