Opinion: The role of biodiversity in mediating crop performance in smallholder agroforestry systems in Rwanda

A timely and significant contribution to this discussion is found in the paper ( to be published soon) by Jean Aime Ruticumugambi, IUCN PhD Scholar, based on the EU-funded DeSIRA Agroforestry Research project in Rwanda implemented by IUCN, titled "Local-scale tree cover modulates pollination services and crop yield in tropical agroforestry landscapes, Rwanda." 

This study is a critical reference point for understanding the complex interdependencies between crops and insect pollinators. It emphasizes that trees and natural vegetation are not just background features but are active agents in maintaining vital ecological processes such as pollination.

The evidence reinforces a long-standing but often overlooked truth: Forests sustain agriculture. When tree cover is integrated into farmlands through forest patches or structured agroforestry systems, it significantly enhances pollination services, boosting crop yields. 

This finding is important for ecologists, agronomists, policymakers, media, farmers, and land planners in both the Global North and the Global South.

This year, the call for more habitats and foraging resources for pollinators resonates strongly. Rwanda’s agroforestry landscapes exemplify how biodiversity conservation can be meaningfully aligned with sustainable agriculture. Honeybees, among the most effective pollinators in many agroecosystems, are particularly vulnerable to threats such as habitat destruction and agrochemical misuse. Without action to safeguard these critical species, the productivity of entire food systems could be compromised.

However, the story of forest influence on agriculture is not without complexity. While forests deliver ecosystem services like carbon storage, water regulation, and biodiversity support, monoculture tree plantations, which lack structural and species diversity, can diminish ecological resilience. 

Such systems often suppress understory vegetation, reduce habitat diversity, and ultimately erode soil health and water cycles. These disservices highlight the need for landscape-level planning favouring native vegetation diversity and multifunctional forest systems over simplistic, uniform tree cover.

Current scientific understanding has primarily centered on individual ecosystem services at the farm scale, with pollination being the most studied. However, forest ecosystems contribute far more broadly to agricultural performance, including pest regulation, microclimate stabilization, water purification, air quality improvement, and nutrient cycling, which are often overlooked services. 

We must shift from focusing on isolated interactions to understanding biodiversity's complex, intersecting benefits across entire landscapes.

As the global community discusses strategies for restoration and climate resilience, Rwanda is uniquely positioned to lead by example. Integrating biodiversity into food systems is not an abstract goal but a tangible necessity, especially in tropical countries where agriculture is central to economic and social well-being. Policymaking, extension services, and land use planning must all embrace biodiversity as a central tenet of sustainable development.

This year’s International Biodiversity Day must be more than a symbolic celebration. It should be a firm reminder of the responsibility to protect and restore nature in protected areas and across farms, communities, and everyday landscapes. Research such as that of Ruticumugambi under the DeSIRA EU-funded Agroforestry Research project provides the scientific backbone for this shift. 

Stakeholders at all levels should take it seriously. Living in harmony with nature is not a poetic ambition; it is the only pathway to ensuring agricultural productivity, ecological stability, and food sovereignty in Rwanda and beyond, leading to sustainable development for both people and nature.

Integrating agroforestry with beekeeping offers several advantages, including increased bee forage. Photo by Jean Claude HABIMANA