Managing Risk in Pine Plantations: Some Silvicultural and Genetic Considerations Phil Dougherty Dougherty & Dougherty Forestry PO Box 82013, Athens, GA 30608 1.888.285.0947
Managing Risk in Pine Plantations Agenda: ➢ What are some key agents of risk that we need to try to manage?
➢ For each of these agents of risk, what are some practical considerations we can take today? ➢ What additional information or tools do forest investors or forest resource managers need to help minimize risk?
Wind: • Hurricanes---Massive areas of damage • High Coastal consideration—return frequency of approx. 4-15 years • Total stand loss, severe stem quality reduction, reduced stand vigor • Tornados---wide strips of destruction • Expressed over a much broader geographical area than hurricanes but with “tornado alleys” that can be quantified. • Blow down, stem quality reduction & vigor reduction • Strong localized Thunderstorms • Smaller areas but of higher frequency and expressed over the full range of managed pine • Blow down, lean, broken tops, loss of foliage
• Down Thrust: • One to a few trees in a local spot • Broken tops or lean
Wind-Hurricanes
Figure 1—Simulated peak hurricane windspeed associated with hurricanes in the Southeast United States over 10- and 50-year periods using FEMA’s HAZUS-MH model. In (a), which is for a 10-year period, only southern Florida and a few coastal census tracts in Alabama, South Carolina, and North Carolina are expected to experience hurricane-force winds (greater than 119 km per hour) within this timeframe. Over a 50-year period, however, the entire region is expected to have winds of at least tropical storm strength, with much higher winds in some coastal areas, as shown in (b). Source: FEMA HAZUS-MH model.
Tornadoes
Wind—Management Tools and Management Considerations • Accelerate rotation development as much as possible---minimize exposure • Pulpwood regimes near the coast not a bad consideration • As move inland, consider planting at a wider spacing to promote more favorable Ht/Dbh ratios and more favorable root system development and anchorage • Thin early, Thin light-The shorter the trees the more wind it takes to blow over • Heavy thinnings create canopy roughness that increase blow-down probability • Use narrow to moderate crown ideotypes but plant them at a spacing that permits good Ht/Dbh development.
• Strive for high survival to minimize canopy roughness and to control excessive limb size and leaf area on scattered individual trees • Do not over-fertilize
Ice Storms:
➢ Can be large in extent ➢ Damage can be almost complete stand loss, top damage, foliage loss ➢ Can occur at a relatively high frequency
Near Charleston, SC
Ice Storms and Wind will reveal defects such as large ramicorn branches and forking
Ideotypes can make a difference in the 1) amount, 2) type and 3)consequence of damage N.E. Ga-2014-15
Broad-Crown OP
Moderate Crown CMP
Broad Crown CMP
Latta, SC—Winter 2014-15
Moderate Crown CMP
Considerations For Managing Ice Storm Risk: Select the best genetics -Crown type---Narrow to Moderate -Strong apical dominance vs broad crown-big branch ideotype Apply good silviculture: -Plant at a spacing to permit good root system development & a favorable Ht/Dbh
-Attain good survival -Thin light and more frequent (Keep neighbor tree support but keep diameter going)
Fusiform Rust
UGA Bugwood
Tree Improvement Studies Study map
Management Considerations for Fusiform Rust:
-Know your genetics -Varietals can take rust incidence to near zero -CMP rust resistant selections can take rust to between 3 to 15% -Good rust resistant OP Elite can take rust to between 525%
-Management intensity ?
Pine Beetles
Management Considerations for SPB— -Genetic choice is not a major tool
-Do not choose off-site genotypes for high risk areas -Applying silviculture that keeps stands in a high vigor is the most important consideration. -Manage stand density from day-1 -Thin as early as possible (Genetics does impact) -Be careful about timing management treatments -Manage site resources—mainly water and nutrients -Chemical site preparation -Fertilize as needed—do not over fertilize -Do understory control if needed -Minimize burning if not needed for stand objectives
Wrap Up
Other Risk Pool is Large! ➢ ➢ ➢ ➢ ➢ ➢ ➢ ➢ ➢ ➢ ➢ ➢
Fire Herbicides Flooding Drought Pales Weevils Hardwood invasion Deer Browse Hogs Beavers Town Ants Fire Ants Other diseases & insects
What do we as investors or forest resource managers need to help minimize risk? USA Today ---Article on timber inverstment in SE USA
-Good investment -Have to be patient -Keeps growing in down market -May have to worry about an occasional beaver or two
1. Need good GIS risk-data base that puts probabilities on the major risk elements that affect our forest –County level at least. 2. Need a better understanding of how to use genetics to reduce risk
3. Need a better appreciation of how to manage stand vigor depending on the potential risk a forest will face over a rotation.
Questions ????