What is Eco-Sourcing?
Eco-sourcing is the process of collecting native plant seeds from a specific area to propagate and reintroduce them back into their natural habitat. It is often used in restoration projects to maintain the genetic composition of local plant populations. In New Zealand, eco-sourcing is widely required by councils and environmental organisations, despite the fact that there are no official regulations or industry standards governing its practice.
The Lack of Regulation in Eco-Sourcing
Unlike other conservation and ecological restoration practices, eco-sourcing in New Zealand is not governed by any formal regulations or industry-wide standards. The preference for eco-sourced plants is largely driven by environmental researchers and the general perception that using local seed stock is beneficial. Councils and regulatory bodies often mandate eco-sourcing for restoration projects, but this is not based on any enforceable rule or universal ecological necessity.
When is Eco-Sourcing Beneficial?
Eco-sourcing can be advantageous in specific situations where plants have evolved distinct adaptations to local conditions. Some potential benefits include:
- Climate Adaptation: Plants from colder regions may develop greater frost resistance.
- Leaf and Growth Variations: Local populations may have different leaf sizes or growth habits suited to their environment.
- Disease Resistance: Some plant populations may have resistance to pests or diseases found in their native area.
In these cases, eco-sourced plants may have a higher survival rate and contribute to maintaining local biodiversity. However, these benefits are species- and site-specific, meaning eco-sourcing is not always necessary.
The Limited Necessity of Eco-Sourcing
Despite its widespread use, eco-sourcing is often applied indiscriminately, even when there is no clear ecological benefit. Many native plant species are naturally widespread and adaptable, meaning they can thrive in multiple ecological districts without issue. The genetic variation within a species often allows for successful growth across different regions, making strict eco-sourcing unnecessary for many restoration projects.
Additionally, eco-sourcing can limit plant availability, slow down restoration efforts, and increase costs due to the challenges of sourcing sufficient seed from specific locations. In cases where large-scale planting is required, a more flexible approach using genetically diverse, regionally suitable plants may be just as effective.
The Process of Eco-Sourcing
Despite the debate over its necessity, eco-sourcing remains a common practice. At Riverside Horticulture, the process includes:
1. Site Selection
Field assessments are conducted during summer and autumn to locate suitable seed collection sites. The selection is based on the ecological district, the health of parent plants, and project requirements.
2. Seed Collection Methods
Seeds are collected using different techniques, such as:
- Direct Harvesting: Collecting mature seeds from plants.
- Ground Collection: Gathering fallen seeds.
- Selective Cutting: Harvesting seed-bearing structures.
Collection follows general best practices, such as gathering seeds from multiple parent plants and leaving sufficient seed for natural regeneration.
3. Seed Processing and Storage
Collected seeds are processed by cleaning, sorting, and storing them under controlled conditions to maintain viability.
4. Batch Tracking and Documentation
Each seed collection batch is assigned a unique identification number recorded in an online system. This tracking system includes:
- Seed source details: Ecological district, GPS coordinates, and site characteristics.
- Photographic records: Images of parent plants and collection sites.
- Collection date and method: Ensuring accurate documentation.
The Role of Ecological Districts
New Zealand is divided into ecological districts, which are geographical areas classified based on climate, geology, soil type, and native vegetation. These districts were developed as part of the Protected Natural Areas Programme (PNAP) to guide conservation planning.
While eco-sourcing is often based on these districts, many plant species naturally extend beyond their designated ecological district boundaries. This challenges the strict application of eco-sourcing, as plants do not always require genetic isolation to thrive.
Eco-sourcing is widely required for restoration projects in New Zealand, but it is not governed by any formal regulations or industry standards. While it can be beneficial in specific situations where plants have developed local adaptations, it is not always necessary. Many native species are naturally resilient and adaptable, making strict eco-sourcing requirements impractical in some cases. A balanced approach, considering both ecological benefits and practical limitations, may be more effective for large-scale restoration efforts.