1. Scientific Rationale

Homegardens are structurally complex, species-rich agroecosystems with critical roles in food security and ecosystem services (Kumar & Nair 2004; Galluzzi et al. 2010).

❗ Key knowledge gaps:

-Limited understanding of how functional diversity influences structure, productivity, and stability Cadotte et al. 2011; Díaz et al. 2007).

- Scarcity of trait-based quantifications of ecosystem service provision (Lavorel & Garnier 2002; de Bello et al. 2010).

2. Objectives and Scientific Hypotheses

Objectives:

• Quantify functional diversity of plant assemblages in diverse homegarden systems.
• Link plant traits to ecosystem service provision and community assembly rules.
• Use quantitative ecological tools (e.g., trait hypervolumes, multivariate analyses) to reveal mechanistic relationships.

H1
Homegardens host higher species richness and functional trait diversity compared to surrounding agricultural or natural reference systems, underscoring their role as refuges for cultivated biodiversity and reservoirs of unique functional traits.

H2
Greater functional diversity of cultivated species in homegardens is associated with higher potential multifunctionality, with expected non-linear (e.g., saturating) relationships.

H3
Functional trait patterns are structured by environmental and management gradients, revealing the action of abiotic filters and human selection.

H4
Distinct functional types of homegardens emerge from species trait composition, reflecting alternative agroecological strategies.

3. Work Plan: Phases & Actions

🏡🌳🌿 WP1 — Homegarden Database

Goal:
Assemble a global, geo-referenced database of plant species cultivated in homegardens.

Actions:

• Conduct a systematic review to identify studies reporting multi-homegarden species data.
  
• Extract or request detailed species lists and associated metadata (e.g. GPS coordinates, management context, environmental descriptors).

–> See details : https://rpubs.com/dbeillouin/Homegardens

🏡🌳🌿 WP1 — Homegarden Database

Lead: Damien Beillouin

Partners & Roles:

• Collins Khoury (San Diego Botanic Garden) + Paul Fauchon: support on taxonomic harmonization.

• Sarah Jones (Bioversity): Complete with other Bioversity datasets?

• Internship : Fantin 4 months- September-December

Collectively:
- Validate the literature review strategy and inclusion criteria.
- Agree on the database structure and the metadata to be systematically extracted.
- Systematic extraction or selected articles?

Deliverable:
- Curated database of species occurrences and associated variables across homegarden systems worldwide. November

🌱📏🧬 WP2 – Trait Database Compilation

Goal: Compile functional, agronomic, and nutritional traits of identified species.

Actions:

• Integrate and harmonize existing trait datasets (e.g. Fauchon et al., XXX traits × ~YYY species). -Triats : Material/non material/supporting, regulating

• Possibility to perform phylogeny-based inference (see Cantwell-Jones et al., 2022)?

Deliverable: Standardized trait database with harmonized metadata.

🌱📏🧬 WP2 – Trait Database Compilation

Lead: Paul Fauchon

Partners & Roles:

• Sarah Jones and Natalia Estrada support on structuration of the trait database

• Marney Isaac and Cyrille Violle help on strategic decision on how handle the complexity of traits data (duplication, mean effect, plasticity, …)

• Lucie Mahaut: Collab/link to the FRB Datashare and other work.

Collectively:
- Validate the trait database compilation strategy.

Deliverable:
- Initial matrix trait-function (for this project) on September
- Full trait database (Chapter 1 PhD Paul) on October

📊🔬🦋 WP3 – Analyse the diversity of species in homegardens

Goal: Map and compare functional/species diversity across homegardens.

Actions:

• Analyse the species diversity (total/per region/biomes/others)
  

• Link the Homegarden species database to the trait database
  

• Apply multivariate methods: PCA, dendrograms, trait hypervolumes (e.g. R package hypervolume)
  

• Compare to some references (total flora, other simplified systems)

Deliverables:

• Functional hypervolume visualizations.

• Diversity indices

📊🔬🦋 WP3 – Analyse the Diversity of Species in Homegardens

Goal:
Map and compare functional and species diversity across homegardens.

Actions:
- Analyse species diversity (overall, per region, biome, etc.)
- Link the homegarden species database to the trait database
- Analyse the diversity of traits
- Compare to reference floras and simplified systems

📊🔬🦋 WP3 – Roles and Collaboration

Lead: Damien Beillouin

Partners & Roles:
- Sarah Jones: support on species diversity analysis
- Marney Isaac and Cyrille Violle: support on functional diversity analyses

Collectively:
- Validate the proposed diversity analyses and their interpretation

Deliverable:
- Diversity analysis report (species/traits) – November–December

💧🍎🐝 WP4 – Trait-Based Ecosystem Function Inference

Goal:
Associate each homegarden with its potential contribution to people and ecosystem services

Actions:
- Link trait profiles to potential NCP: regulation (stability), material (food, fibre, medicine), and cultural values
- Use trait–function relationships to estimate service provision potential

Deliverables:
- Trait-based ecosystem service profiles
- Comparative analysis across systems

💧🍎🐝 WP4 – Roles and Collaboration

Lead: Damien Beillouin / Paul Fauchon

Partners & Roles:
- Delphine Renard: linking traits to ecosystem service proxies
- Bruno Rapidel: agroecological interpretation (e.g. carbon, productivity)
- Sarah Jones: validation and comparison with Bioversity datasets

Deliverable:
- Functional service profiles and report – December

4. 📆 Project Gantt Chart