How Agroforestry Systems are Classified

Agroforestry is one of the most versatile approaches to land management, combining trees with crops, livestock, or both on the same piece of land. But not all agroforestry looks the same. A farm in the highlands of East Africa where cattle graze under scattered trees is very different from a home garden in Southeast Asia with layered fruit trees, vegetables, and spices. To make sense of this diversity, scientists have developed classification systems that group agroforestry practices based on specific criteria. Understanding these classifications is essential for selecting the right system for a given location, climate, and livelihood need.

Why classify agroforestry systems? 🔗

With hundreds of agroforestry practices in use worldwide, a clear framework is needed to organize information, guide research, and help farmers and policymakers make informed decisions. According to ICRAF’s foundational work, classification provides a structured way to evaluate existing systems and develop action plans for their improvement. Without it, communicating about agroforestry across regions and disciplines becomes extremely difficult. A good classification scheme also helps extension workers recommend appropriate practices based on a farmer’s specific environment and economic situation.

Key criteria used for classification 🔗

Agroforestry systems can be classified using several criteria. The four most widely recognized bases are the system’s structure, function, socio-economic characteristics, and ecological spread. Each of these looks at agroforestry from a different angle, and together they provide a comprehensive picture of how and why a system works.

Structural basis 🔗

The structural classification is the most commonly used and the most straightforward. It looks at what components are present in the system (trees, crops, animals) and how they are arranged in space and time. Based on the nature of components, agroforestry systems fall into three major categories – agrisilvicultural, silvopastoral, and agrosilvopastoral – plus a few specialized types. This approach was first developed during ICRAF’s global inventory of tropical agroforestry systems, as described in research by P.K.R. Nair, one of the leading scholars in the field.

The spatial arrangement of components matters too. Trees and crops can be planted in alternate rows, in strips (alley cropping), along borders, or in a random mixture. The temporal arrangement is equally important: components may exist simultaneously (as in intercropping under coconut palms), sequentially (as in the taungya system where crops are grown during the early years of a tree plantation), or in an intermittent pattern where different components occupy the land at different times of the year.

Functional basis 🔗

The functional classification groups systems based on the role or output of their components. Every agroforestry system performs at least one of two broad functions: productive or protective.

Productive systems focus on generating outputs that meet basic household or market needs – food, fodder, fuelwood, timber, and other products. Home gardens, intercropping systems, and plantation-crop combinations are typical productive systems. Protective systems, on the other hand, prioritize environmental services. These include windbreaks and shelterbelts that reduce wind erosion, live fences that demarcate boundaries, and hedgerow plantings that control soil erosion and conserve moisture. Many systems serve both functions simultaneously. For instance, as the FAO notes, hedgerow intercropping can improve soil fertility (protective role) while also yielding crops for household consumption (productive role).

Socio-economic basis 🔗

Not every farmer operates at the same scale or with the same resources. The socio-economic classification accounts for differences in management intensity, scale of production, and economic goals. At one end of the spectrum, subsistence systems are practiced by smallholder families with limited land and capital. Shifting cultivation and scattered farm trees are common examples – the aim is to meet household food and fuel needs, with only marginal surplus for sale. At the other end, commercial systems are designed for large-scale production aimed at markets. Tea or coffee grown under shade trees on large estates is a classic example. In between, intermediate systems operate on small to medium-sized farms, producing enough for home use while also generating income from surplus. The socio-economic lens can be further refined by the level of technology used – low-input systems relying on manual labour versus high-input systems using mechanization and purchased inputs.

Ecological basis 🔗

Different agroforestry practices thrive in different environments. The ecological classification groups systems by the agro-ecological zone where they are practiced – lowland humid tropics, arid and semi-arid tropics, tropical highlands, temperate regions, and so on. For example, multi-layered home gardens are well-suited to humid tropical zones with abundant rainfall, while scattered trees on rangelands (such as Prosopis cineraria in the Thar Desert of India) are adapted to arid conditions. This classification is especially useful for researchers and policymakers trying to identify which systems can be successfully transferred or adapted across regions with similar climatic and soil conditions.

The three major system types 🔗

Regardless of the classification criterion used, almost every framework starts by identifying the three core system types based on their biological components. These are the building blocks of agroforestry classification.

Agrisilvicultural systems (crops + trees) 🔗

Agrisilvicultural systems combine agricultural crops with trees or shrubs on the same land. This is the most diverse category and includes a wide range of practices. According to CGIAR’s AgLED platform, examples include improved fallows (where fast-growing trees restore soil fertility between cropping cycles), taungya systems (crops grown alongside newly planted forest trees), alley cropping (rows of trees alternating with crop strips), and multi-storey home gardens with several vegetation layers.

Other practices under this category include growing nitrogen-fixing trees like Leucaena or Gliricidia alongside food crops to naturally enrich soil nitrogen, establishing windbreaks and shelterbelts at farm boundaries to protect crops from strong winds, and planting live fences to mark property lines while producing fodder or fuelwood. Shade-grown coffee and cocoa plantations – where crops grow under a canopy of taller timber or fruit trees – are among the most economically significant agrisilvicultural systems globally.

Silvopastoral systems (trees + pastures/animals) 🔗

Silvopastoral systems integrate trees or shrubs with pastures and livestock. These are especially important in regions where animal husbandry is a major livelihood activity. Common practices include maintaining trees on rangelands or grazing pastures, establishing protein banks (dense plantings of protein-rich shrubs like Leucaena or Sesbania for animal fodder), and allowing livestock to graze under plantation crops like coconut or rubber.

Research compiled by ScienceDirect shows that silvopastoral systems are found worldwide – from the Dehesa systems of Spain and Portugal (where livestock graze under scattered oaks) to ranching landscapes in Latin America and pastoral systems across sub-Saharan Africa. These systems can be managed extensively (low-density trees on open rangeland) or intensively (high-density fodder shrubs combined with improved tropical grasses). Intensive silvopastoral systems can achieve strong productivity from local feed sources, often without the need for synthetic fertilizers since nitrogen-fixing plants are commonly included.

Agrosilvopastoral systems (crops + trees + animals) 🔗

The most complex category, agrosilvopastoral systems bring together all three components – crops, trees, and livestock – on the same land unit. These systems are particularly common in the highlands of East Africa, parts of South and Southeast Asia, and Latin America. A well-known large-scale example is Brazil’s Integrated Crop-Livestock-Forestry (ICLF) system, which combines grain production, cattle ranching, and timber tree plantations in a single rotational framework.

At a smaller scale, tropical home gardens that include fruit trees, vegetable patches, and poultry or goats are classic agrosilvopastoral systems. Research published on agrosilvopastoral practices highlights that these systems are a valuable option for circular food systems because they recycle more nutrients through the integration of livestock, pastures, and crops. In dryland Africa, these systems provide essential goods – including woodfuel, fodder, and medicinal products – to an estimated 320 million people.

A study conducted by ICAR-CRIDA in South India found that agrosilvopastoral systems using trees like Hardwickia binata combined with finger millet and legume fodder significantly improved soil nitrogen, phosphorus, and organic carbon levels while ensuring year-round fodder supply for small ruminants.

Other specialized systems 🔗

Beyond the three main types, several specialized agroforestry practices deserve mention. Apiculture with trees integrates beekeeping into tree-based land-use systems, generating honey and beeswax while benefiting from pollination services. Aquaforestry combines fish or shrimp farming with tree cultivation – a practice seen in waterlogged or coastal areas of South and Southeast Asia. Multipurpose woodlots serve as dedicated tree plots that provide a mix of timber, fuelwood, fodder, and fruit. These specialized systems are sometimes grouped under a fourth “other” category in structural classification frameworks.

How classification helps in practice 🔗

Classification is not just an academic exercise. It has direct practical value. When a development agency wants to promote agroforestry in a new region, classification helps them identify which system types have worked in similar agro-ecological zones elsewhere. When a smallholder farmer wants to diversify income, understanding the functional classification helps them choose a system that balances production and environmental protection.

For researchers, classification provides a common language. Saying “silvopastoral system in tropical savannas” immediately communicates a great deal about the components, the environment, and the likely management approach. For policymakers, it helps in designing targeted support – subsidies for commercial agrisilvicultural systems might look very different from extension services for subsistence agrosilvopastoral practices.

The FAO’s agroforestry module emphasizes that the suitability of any system depends on land characteristics, the needs of landowners, and the availability of resources like labour, capital, and technology. Classification frameworks help organize this complex decision-making process.

Tailoring systems to local conditions 🔗

One of the greatest strengths of agroforestry is its adaptability. Classification criteria are not used in isolation – they are often combined to describe a system precisely. For instance, a system might be described as a “commercial agrisilvicultural system in the lowland humid tropics focused on soil conservation” – combining structural, socio-economic, ecological, and functional criteria in a single description. This layered approach ensures that the system is tailored to both the environment and the community it serves.

In practice, the most effective agroforestry designs emerge when farmers, researchers, and extension workers collaborate. Local knowledge about which tree species grow well, which crops tolerate shade, and how livestock behave under tree canopies is just as important as formal classification. The classification framework simply provides a structured starting point for that conversation.

What do you think? Which classification criterion – structural, functional, ecological, or socio-economic – do you believe is most useful for designing agroforestry systems in your region? And can a single classification framework truly capture the diversity of agroforestry practices around the world, or do we need more flexible, locally adapted approaches?

References

1. https://link.springer.com/article/10.1007/BF00122638
2. https://link.springer.com/chapter/10.1007/978-3-030-75358-0_3
3. https://www.fao.org/sustainable-forest-management/toolbox/modules/agroforestry/basic-knowledge/en/?type=111
4. https://agledx.ccafs.cgiar.org/emissions-led-options/production-systems/agroforestry/
5. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/silvopastoral-systems
6. https://www.researchgate.net/publication/354462045_Agroforestry_3_Agrosilvopastoral_systems
7. https://www.sciencedirect.com/science/article/abs/pii/S0308521X23002172
8. https://www.fao.org/sustainable-forest-management-toolbox/modules/agroforestry/en