Biodiversity – the variety of life on Earth, from birds in the sky to insects on a leaf, trees rooted in the soil to fungi underground. It encompasses every plant, animal, and microorganism, with interconnected roles to maintain the health and resilience of our planet’s ecosystems.
When biodiversity flourishes, ecosystems are more productive, resilient, and capable of supporting life, including human life. Biodiversity underpins the systems that provide our food, clean our air and water, regulate our climate, and support our physical and mental well-being.
The Biodiversity Crisis
But today, biodiversity is declining at an unprecedented rate. Species are becoming extinct, habitats are disappearing, and ecosystems are being pushed beyond their capacity to recover. The consequences are global and far-reaching.
The Role of Biodiversity in Food, Health, and Climate
The good news: restoration is possible.
Efforts to protect and restore biodiversity can reverse these trends. Restoring biodiversity supports food security, climate resilience, economic stability, and public health. And across TREES Forest Gardens in sub-Sahara Africa, restoration of ecosystems is already happening. For farmers, biodiversity is not an abstract concept or a concern limited to conservationists. It is central to their work sustaining life and livelihoods:
Food and nutrition
A significant portion of the human diet is derived from plants, and pollinators are essential to the production of many fruits and vegetables. Greater plant diversity contributes to more resilient food systems and diets rich in nutrients (FAO).
Medicine and health
Approximately 80 percent of people in rural communities rely on plant-based medicines. A wide variety of flora ensures a broader base for traditional healing and biomedical research. Biodiverse ecosystems also reduce the risk of zoonotic disease outbreaks. (WHO).
Climate regulation
Forests, wetlands, and diverse agricultural systems, including those with high tree species richness, sequester carbon, regulate temperature, and reduce erosion. (IPBES).
Disaster risk reduction
Healthy ecosystems help buffer the effects of extreme weather events such as floods, droughts, and storms. Deep-rooted trees, in particular, help stabilize soils and manage water cycles (UNDRR).
Cultural and spiritual value
Nature provides inspiration, connection, and a sense of place. It supports mental health and community well-being (UNEP).
The Importance of Plant and Tree Diversity in Restoration
Plant and tree biodiversity is a critical driver of ecological stability and function. Diverse tree species contribute to varied canopy structures, soil fertility, pest control, and habitat formation. In restoration contexts, tree diversity supports a broader array of wildlife, improves resilience to pests and diseases, and ensures the long-term sustainability of ecosystems.
In agricultural landscapes, monocultures are particularly vulnerable to environmental stress. But polycultural systems, like the Forest Garden Approach, mimic natural ecosystems by integrating diverse plant and tree species to create layered, regenerative landscapes.
This is not just reforestation; it’s functional, intentional restoration led by farmers who know their land best.
A Farmer-Led Path to Restoration
Trees for the Future’s Forest Garden Approach enables smallholder farmers to restore degraded land by planting diverse species of trees, shrubs, and crops in carefully designed systems. These Forest Gardens improve food security and livelihoods while enhancing local biodiversity.
Critically, the intentional integration of tree species, including fruit trees, nitrogen-fixers, timber, and medicinal trees, ensures that these systems deliver both ecological and economic benefits. Tree diversity drives ecosystem health while supporting household needs and market opportunities.
Farmers implementing this approach are not only benefiting their households and communities, they are actively restoring ecosystems. Their work contributes directly to international biodiversity goals, including the Kunming-Montreal Global Biodiversity Framework and the Sustainable Development Goals.
This is a scalable, evidence-based model for sustainable development led by the very people managing the land.
Scientific Validation
Monitoring activities implemented across Forest Gardens for scientific study.
To bring true credibility and transparency to climate and environmental work, it’s not enough to count trees and measure carbon. We must also understand the impact of land use on biodiversity, ecosystems, and communities. That’s exactly what Trees for the Future is doing in Kenya’s Lake Victoria watershed through a groundbreaking, multi-year bioacoustic study.
In partnership with bioacoustic innovator Wildmon.AI, Trees for the Future is using AI-powered passive acoustic monitoring to track biodiversity across more than 70 Forest Garden sites in Kenya. These recorders “listen” for birds, insects, and amphibians, enabling fast, repeated, and non-invasive biodiversity tracking at scale.
Key Findings from the Biodiversity Report:
- 128 species detected, including 123 bird species, across 67 Forest Garden sites
- 14% increase in bird species richness after three years in the Forest Garden Program
- Higher species occurrence in Forest Gardens enrolled for one to three years compared to newer sites
- Greater biodiversity associated with increased canopy height and proximity to Lake Victoria
- Presence of species of conservation concern, such as the grey crowned crane (Balearica regulorum) and the woodland kingfisher (Halcyon senegalensis)
These findings confirm that Forest Gardens contribute significantly to habitat quality and species recovery. The vegetative complexity created by planting a wide variety of trees and shrubs is essential for attracting and sustaining wildlife.
The full biodiversity report is available for download here, and supports the inclusion of Forest Gardens in broader biodiversity and climate strategies.
How the Study Was Conducted:
- Scientific Sampling Design: Sites were selected to reflect a range of ages, elevations, and conditions across the Lake Victoria watershed.
- Passive Acoustic Monitoring: Rugged recorders captured soundscapes without disrupting habitats.
- Training and Local Capacity Building: Kenyan field technicians were trained to manage devices and data collection.
- AI Model Development: Audio files were converted into spectrograms and processed through neural networks trained to identify species.
- Expert Review: All identifications were reviewed and validated by biologists for accuracy.
- Ongoing Monitoring: This four-year study includes annual monitoring and comparisons with control sites to track biodiversity trends over time.
Spectrogram pattern matching validation process in the Wildmon platform. The clips show recordings of the White-Browed Robin-Chat, as seen in the photo inset.
Key Insights from the Monitoring Approach:
Data-Driven, Transparent Impact: This four-year study sets a new benchmark for environmental reporting. By collecting, validating, and sharing biodiversity data over time, TREES ensures that Forest Gardens deliver measurable, verifiable, and transparent impact beyond carbon metrics.
Measuring Biodiversity at Scale: Traditional biodiversity assessments are expensive and time-consuming. Using AI-powered acoustic recorders, TREES is able to monitor biodiversity efficiently, repeatedly, and without disturbing habitats, making it possible to track changes across dozens of sites.
Forest Gardens = Habitat for Wildlife: Replacing monocultures like maize with diverse species of trees, shrubs, and crops mimics natural forest systems and creates vital habitat for birds, pollinators, and other species.
AI + Science = Scalable Innovation: Advanced neural networks trained on spectrograms (visual sound signatures) rapidly and accurately identify species. This innovation reduces labor costs and allows scalable biodiversity monitoring across thousands of farms.
Habitat Quality is Improving: Older Forest Gardens with taller tree canopies consistently show increased species richness, including rare and forest-specialist birds, key indicators of ecosystem recovery and resilience.
A Replicable Model for Measurable Impact
The Forest Garden Approach is not only evidence-based, it is also replicable, farmer-led, and aligned with international conservation and climate frameworks. It delivers measurable improvements in species richness, habitat quality, and ecological function, while simultaneously addressing food insecurity, poverty, and climate vulnerability
Plant and tree diversity is not just a feature of the Forest Garden, it is a central mechanism of its success. Diverse trees and crop play a direct role in restoring degraded land by:
- Creating microhabitats for insects, birds, and soil organisms
- Improving soil health and water retention
- Supporting pollinators essential to food production
- Increasing climate resilience and carbon sequestration
By mimicking the structure and function of natural ecosystems, Forest Gardens restore degraded landscapes in a way that is economically viable, ecologically sound, and socially inclusive.
As more farmers adopt this approach and continue to manage their land sustainably, the biodiversity benefits compound. This positions Forest Gardens as a credible, community-driven solution to biodiversity loss.
Biodiversity for the Future
Biodiversity is foundational to life on Earth. Its protection and restoration are not only environmental imperatives but social and economic ones as well.
Evidence shows that nature-based, farmer-led solutions work. Forest Gardens support both people and the planet; improving food systems, strengthening climate resilience, and restoring biodiversity through the power of plant and tree diversity.
And perhaps most importantly, they remind us that sustainable solutions already exist and that communities closest to the land are leading the way.