Woody Biomass Forests | Tree Selection and Advice

As New Zealand transitions toward renewable energy sources, biofuel derived from woody biomass offers a promising pathway. Biofuel sourced from energy forests—forests planted specifically for biomass production—capitalises on fast-growing tree species like radiata pine, eucalyptus and poplar. These species are ideal for short-rotation forestry due to their rapid growth and adaptability to New Zealand’s varied climates, maturing in optimal economic timeframes of 8 to 20 years. Through high-density planting and selecting fast-growing trees, New Zealand could create a consistent supply of sustainable biomass.

With key sectors, such as healthcare and dairy, increasingly moving away from fossil fuels to biofuel-powered boilers for electricity and heat generation, the demand for biofuel continues to rise. The financial potential for landowners and foresters to supply woody biomass to meet this demand adds economic appeal, providing a way to support both New Zealand’s energy independence and rural communities. By investing in the growth and supply of woody biomass, we are shaping a renewable energy foundation that may soon underpin much of New Zealand’s energy needs.

Tree Varieties for Woody Biomass

Growing trees for biofuel requires species that thrive across New Zealand’s landscapes and reach maturity quickly to meet the short-rotation demands of biofuel production. Here are some popular choices, their ideal conditions, and benefits:

• Radiata Pine
  • Optimal Conditions: Thrives in well-drained, moderately fertile soils; tolerates frost and coastal exposure.
  • Pros: Radiata pine is one of the fastest-growing timber trees in New Zealand, reaching an optimum harvestable size in 12–18 years. It adapts well across regions and offers high biomass yield.
  • Cons: In low-nutrient soils, it may require additional maintenance and fertilisation.
  • Growth Timeline: Reaches its optimum size for biofuel within 15 years.
    
• Eucalyptus
  • Optimal Conditions:Varieties like Eucalyptus nitens, Eucalyptus regnans, and Eucalyptus delegatensis grow well to a wider range of New Zealand climates. These varieties have provein their worth as short rotation crops for woody biomass varieties.
  • Pros: Known for its high-density wood and rapid growth, eucalyptus can mature in 8–15 years, with some varieties offering resilience to drought.
  • Cons: Some varieties are sensitive to hard frost so the right choice for the area is important.
  • Growth Timeline: Typically achieves an optimum size in 8–12 years.
    
• Poplar
  • Optimal Conditions: Thrive in moist, fertile soils and tolerate varied climates, including areas with frosts and elevation.
  • Pros: These trees establish quickly, providing soil stability and erosion control with well-developed root systems.
  • Cons: While quick-growing, they generally yield less biomass per hectare compared to pine and eucalyptus.
  • Growth Timeline: Matures for harvesting in 10–15 years.

Pricing

The cost of seedlings varies based on the species, seedling quality, and bulk ordering. Below is an indicative chart with approximate pricing per seedling, showing the initial investment required for setting up an energy forest:

These costs provide a general idea of the upfront expenses, with the potential price adjustments depending on the nursery, region, and planting scale.

Planting Advice

Planting Density
To achieve optimal biomass production in energy forests, the recommended planting density is between 800 and 1,600 trees per hectare. This density encourages uniform growth and maximises biomass yield.

Planting Season
Late autumn to early winter is the best planting season for energy forests in New Zealand. The cooler temperatures and higher soil moisture during these months help young trees establish strong root systems before the warmer seasons. This timing enhances growth rates and minimises water stress during early stages.

Ordering Trees

To ensure smooth project planning and planting, it's essential to arrange for seedlings well in advance. The following steps provide a guide to sourcing and ordering trees:

• When to Contact the Nursery
  For larger projects, get in touch with a reputable nursery 6–12 months ahead of your planting schedule. Advanced planning ensures the availability of the species and seedling sizes you need, especially in bulk orders.
  
• Choosing the Right Nursery
  Select a nursery that specialises in forestry or biofuel crops, as they are better equipped to supply seedlings of the right quality and specifications. Specialist nurseries can also advise on the best tree varieties and densities for specific regions.
  
• The Ordering Process
  1. Initial Consultation: Begin by discussing your project goals, location, and ideal tree varieties with the nursery team.
  2. Quote and Order Confirmation: Once you've finalised the species and quantity, the nursery will provide a detailed quote and confirm order details.
  3. Scheduling Delivery: Arrange for delivery during the recommended planting season to reduce storage time and support optimal planting conditions.
  4. Planting Support: Some nurseries offer guidance on planting techniques or even on-site planting services, ensuring proper handling and better growth outcomes.

Shifting to biofuel production is a progressive step towards a more sustainable future for New Zealand, and cultivating energy forests is a practical and rewarding way to contribute to this vision. Fast-growing species like radiata pine, eucalyptus, and poplar form the backbone of biofuel supplies, supporting New Zealand’s renewable energy needs while creating a steady income source for landowners and rural communities. By fostering biofuel crops, we’re investing not just in energy independence but in the ecological and economic resilience of our regions.

If you’re ready to establish an energy forest, reach out to a trusted nursery to discuss the ideal species and planting strategies for your area. Together, we can drive New Zealand’s renewable energy journey, creating greener energy and landscapes for generations to come.