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Survival and early growth of Pinus radiata D.Don in some plantations in New South Wales, Australia

An 11-site study in New South Wales found that while Pinus radiata survival at 10 years was significantly higher for cuttings and container-raised stock, open-rooted stock surprisingly produced greater wood volume despite lower survival rates, suggesting a need for further research into nursery methods to optimize forest yields.

Original authors: P.W. West, P. Green, J. Turner

Published 2026-07-24

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CC BY 4.0

Original authors: P.W. West, P. Green, J. Turner

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine a world where trees are the ultimate athletes, and the forest is their stadium. But before they can run the race of growing tall and strong, they have to survive the "tryouts" in a nursery. In the world of forestry, scientists are constantly asking: what's the best way to raise these young trees so they don't just survive, but thrive? It's a bit like deciding whether to raise a baby bird in a cozy, climate-controlled incubator (a container) or let it grow in a big, open field (open-rooted). Do they need the safety of a box, or does the freedom of the dirt make them tougher? This question matters because forests are the lungs of our planet and the source of the wood we use for everything from houses to paper. If we can figure out the perfect recipe for raising trees, we can grow more wood, faster, and with less waste.

Now, picture a team of researchers in New South Wales, Australia, setting up a massive tree experiment. They didn't just plant a few trees; they set up 460 different "plots" across 11 different locations, like testing a new video game strategy on 11 different maps. They wanted to see if the way they grew the trees mattered. They tested three big variables: where the trees were planted (the 11 different sites), how they were started (from a seed or from a cutting, which is like cloning a parent tree), and where they were raised in the nursery (in plastic pots or in the ground). Think of it as a giant tree tournament with 11 different arenas, two types of players, and two different training camps.

After waiting ten years—about a third of a tree's teenage years—the researchers checked the scoreboard. The first thing they found was that the location mattered a lot. Just like some sports teams have home-field advantage, some sites were just better for trees than others. Survival rates ranged wildly, from a low of 61% to a high of 95%, depending on the specific patch of land.

But here is where the story gets interesting. When they looked at the "how" and "where" of the nursery, they found some surprising winners. Trees that were started from cuttings (clones) had a 7% better chance of surviving than those started from seeds. Even more surprising, trees raised in containers (the plastic pots) survived 9% better than those raised in the ground (open-rooted). It seems the "incubator" method gave the little trees a better head start against the elements.

However, the plot thickens when we look at how much wood the trees actually produced. You might think the trees that survived better (the container-raised ones) would also be the biggest wood producers. But the data told a different story. When the researchers measured the total wood volume at 10 years, they found that the trees raised in the ground (open-rooted) actually produced 8.1 cubic meters per hectare more wood than the container-raised trees, even though fewer of them survived. It's as if the open-rooted trees, despite losing more teammates along the way, grew so much bigger and stronger that they made up for the loss. The type of starting material (seed vs. cutting) didn't seem to change the final wood amount at all.

So, what's the takeaway? The paper suggests that while container-raised trees are the "survival champions," the open-rooted trees might be the "growth champions," eventually yielding more wood. The authors are careful to say this is a suggestion based on their data, not a final rule for every forest in the world. They admit they don't know exactly why the open-rooted trees grew so much bigger, but the numbers show a clear difference. It's a reminder that in nature, being the most likely to survive isn't always the same as being the most likely to become a giant. For forest managers, this means there's still a lot of research to do to figure out the perfect balance between keeping trees alive and making them grow tall.

Technical Summary: Survival and Early Growth of Pinus radiata D.Don in New South Wales Plantations

Problem Statement
Commercial Pinus radiata plantations in New South Wales (NSW), Australia, have traditionally relied on routine nursery production methods, specifically shifting from open-rooted to containerized systems over the past two decades. This transition was driven by business imperatives—such as improved workplace safety, reduced material inputs, and automation capabilities—rather than empirical research. Consequently, there is a lack of data regarding which nursery systems (open-rooted vs. containerized) and propagation methods (seed vs. cuttings) best ensure stock survival and rapid early growth across diverse NSW sites. This study addresses the gap in understanding whether these production systems interact with site conditions to influence 10-year survival and wood volume yields.

Methodology
The research utilized an 11×2×2 factorial experiment conducted across 11 first-rotation plantation sites in southeastern NSW, established between 2005 and 2008. The study encompassed 460 experimental plots with an unbalanced design. The experimental factors were:

Site: 11 distinct locations varying in soil type (Kurosols or Kandosols), altitude (450–740 m), and annual rainfall (620–1,020 mm).
Propagation Method: Stock derived from cuttings (10–15 month nursery crop) versus seed (7–10 month nursery crop).
Nursery Raising Method: Containerized systems (plastic containers with pine bark/coir media) versus open-rooted systems (in-ground raised beds with root wrenching/trimming).

At 10 years of age, researchers recorded proportional survival and estimated stand stem wood volume. Volume was calculated as the product of stand basal area and height (using the largest 100 trees per hectare) multiplied by a form factor of 0.31. Statistical analysis involved:

Analysis of Variance (ANOVA): Using the GLM procedure in SAS with Type III sums of squares and LS-means to assess main effects and interactions on survival.
Mixed Model Regression: A non-linear mixed model ( $V = p_1 + (p_2 + u_2)S + p_3N$ ) was employed to analyze the relationship between stem wood volume ( $V$ ) and survival ( $S$ ), accounting for site-specific random effects ( $u_2$ ) and nursery method ( $N$ ). Covariance analysis was deemed inappropriate due to significant variations in regression slopes across treatments.

Key Results

Survival Rates: Survival at 10 years ranged from 61% to 95% across sites.
- Site Effect: Significant differences in survival were observed between sites, reflecting environmental variability.
- Propagation Effect: Trees propagated from cuttings had a 7% higher survival rate than those from seed.
- Nursery Effect: Container-raised stock demonstrated a 9% survival advantage over open-rooted stock.
- Interactions: No significant interactions were found between site, propagation, or nursery methods regarding survival.
Wood Volume Yields:
- A direct, linear relationship was observed between proportional stock survival and stand stem wood volume across all sites.
- Nursery Method Impact: Contrary to the survival advantage of containerized stock, stands established with open-rooted stock yielded an average of 8.1 m³ ha⁻¹ more wood volume at 10 years than those with container-raised stock. This difference was consistent across all sites and survival rates.
- Propagation Method Impact: No statistically significant difference in volume production was found between cuttings and seed.

Significance and Claims
The paper concludes that nursery production methods significantly influence both the survival and early growth performance of P. radiata, though the effects are complex. While containerized stock offers a survival advantage (9%), open-rooted stock results in higher wood volume yields at the 10-year mark (8.1 m³ ha⁻¹). The authors suggest that the superior growth of open-rooted stock may have compensated for their lower survival rate.

The study highlights that the circumstances under which stock is raised can alter subsequent forest development, yet the magnitude of these effects may be small enough that their management implications require careful consideration. The authors explicitly state they could not determine the physiological mechanisms behind the higher volume yields of open-rooted stock. They note that while this research addresses survival and volume, other unreported NSW research investigates how these methods affect stem deformity and branching, which are critical for wood quality. The paper suggests that with the advent of robotics and mechanical planting, forest managers and silviculturists should re-evaluate current nursery practices to optimize establishment and early growth, rather than relying solely on business-driven shifts in production systems.

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