Transcript Biometric Challenges of Hawaii Forest Management

Biometric Challenges of Hawaii
Forest Management
N. Koch
Research Forester
Introduction
• Current problem:
– Lack of adequate data and models for proper native
forest management
• History
– How did this come about?
• Present situation
– Why such models are more important today?
• Currently used methods for forest management
– Mostly empirical
Focus on koa
• External volume equations for most exotic
species are well known
– Allows for adequate management, with
reservations
• No site indexes
• No stocking guides
• No growth curves (yet)
– However, better than the situation for koa!
Background
• Historic lack of dedicated forest industry in
Hawaii
– Most forest cleared for other uses
• Grazing
• Agriculture
– Sugar
– Pineapple
– Remaining forests dedicated to non-timber use
• Watershed protection
• Parkland
Background (cont.)
• Forest industry relegated to “mining” of
timber resources
– Clearing land for agriculture
– Extraction of pasture timber
– Small-scale extraction in watershed forests
Existing models
• Early efforts by the Forest Service
– 1960’s and 1970’s:
“Predicting volumes in four Hawaii hardwoods...first
multivariate equations developed” Sharpnack,
David (1966)
...requires 4 inputs:
DBH
HT
TDIB (top diam. inside bark)
Diam. Inside bark at 1st 16’ log
Existing models (cont.)
Acacia koa volume (cuft)
V = -13.8719 + 1.7332 (DBH) – 1.2125 TDIB +
0.0022 DBH2 (HT) (FC) + 0.0033 TDIB2 (HT) (FC) +
11.7450 (HT)
TDIB – Top inside bark diameter
FC - Form class = Inside bark diameter at 16’ / DBH
...Laborious to collect data and process it!!!
Existing models (cont.)
• Early efforts by the Forest Service
– 1960’s and 1970’s:
“Guide to log defect indicators in Koa, Ohia...
preliminary rules for volume deductions”
Burgan et al. (1971)
... Difficult to apply in field estimations
Present situation
• Demand for quality forest products outstrips
supply, particularly in native woods
– Increased conversion of pastures to forest
– Increased interest in active forest management
• A shift from extractive uses
– Forest management in Hawaii as a worthwhile
alternative to agriculture/grazing
• Environmental concerns
• Government incentives
• Wood prices (koa is worth more than mahogany)
Present situation (cont.)
• Forest management for timber based on
rudimentary equations
– Eg. Use of Acacia melanoxylon in lieu of A.
koa
• Difficult to establish value of standing trees
• Little data on site indexes, growth curves,
stocking guides
– Unknown returns on forest investment
– Difficult to prepare silvicultural prescriptions
Present situation (cont.)
• Use non-volume basis for native forest
management
– Basal area
– Stems/acre
– Diameter distribution
• Not able to utilize volume control for
allowable harvests
Complicating factors
• Acacia koa
– Variable growth form
• Young forest
Young, forest grown Koa
Young, forest grown Koa
Complicating factors
• Acacia koa
– Variable growth form
• Young forest
• Pasture & forest relicts
Forest relicts
Forest relicts
Forest relicts
Complicating factors
• Acacia koa
– Variable growth form
• Young forest
• Pasture & forest relicts
• Old field
Old field Koa
Old field Koa
Complicating factors
• Acacia koa
– Variable phenotype
• Young forest
• Pasture & forest relicts
• Young pasture
– Genetic variability
• Heartwood (important – value driver)
• Elevational
• Inter-island
Genetic variability of heartwood
Current work
• Exotics:
– Division of forestry and wildlife has prepared
local volume equations for
• Eucalyptus grandis
• Eucalyptus saligna
• Flindersia brayleyana
– Forest solutions working on young koa volume
equations (DBH & HT based)
• Taper data collected
Current challenges
• Coordination of data collection and
synthesis
– Preparation of local volume equations, growth
models and stocking guides
• Partnerships with land management agencies
• Collaboration with biometry experts
• Invitation
– Forest Solutions would like to collaborate with
biometry experts to resolve these issues