Allometric equations for Sequoia sempervirens in forests of different ages
| Autor: | Ethan J. Coonen, Benjamin G. Iberle, Robert Van Pelt, Jim Campbell-Spickler, Allyson L. Carroll, Stephen C. Sillett |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Canopy Biomass (ecology) geography geography.geographical_feature_category biology Crown (botany) Sequoia Tree allometry Forestry Understory Management Monitoring Policy and Law Old-growth forest biology.organism_classification 010603 evolutionary biology 01 natural sciences Environmental science Silviculture 010606 plant biology & botany Nature and Landscape Conservation |
| Zdroj: | Forest Ecology and Management. 433:349-363 |
| ISSN: | 0378-1127 |
| Popis: | Mature second-growth forests dominated by Sequoia sempervirens occupy only two percent of the species’ current distribution yet represent an important benchmark for restoration management. Here we develop new allometric equations for these forests based on 44 trees 23–84 m tall, which can be used to estimate leaf, bark, cambium, sapwood, and heartwood quantities, including biomass and carbon content, from ground-based measurements of trunk diameter, height, and crown size. New equations complement those already available for S. sempervirens in young and old-growth forests and should be applied judiciously. We use fixed area plots in a 159-year-old second-growth forest (0.5 ha) and a primary forest with trees >1100 years old (1.0 ha) to compare three sets of equations. Whereas equations from young forests underestimate biomass in older forests, new equations underestimate trunk and overestimate branch quantities in the old-growth forest, and equations from old-growth forests do the opposite in the mature second-growth forest. Despite the great age difference, canopy structure of these low-elevation, alluvial forests is similar with S. sempervirens stratified into dominant and subordinate crown classes towering above a diminutive understory. Dendrochronological reconstruction of heights and wood radii for nine individuals reveal that both forests have trees producing >300 kg yr−1 with tall trees in the old-growth forest producing up to 800 kg yr−1 in recent decades. Sequoia sempervirens represents nearly 100% of biomass and 83 to –92% of leaf area in the second-growth (total LAI = 15.0) and old-growth (total LAI = 19.3) forests, respectively. The best allometric equations estimate that the second-growth forest holds 1667 Mg ha−1 of aboveground biomass (837 Mg C ha−1), 56% of which is heartwood, whereas the old-growth forest holds 4595 Mg ha−1 of aboveground biomass (2332 Mg C ha−1), 76% of which is heartwood. Restoration management has potential to harness the carbon sequestration potential of S. sempervirens by promoting heartwood accumulation through silviculture. |
| Databáze: | OpenAIRE |
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