2016 Overview of Forest Health Conditions in Southern British Columbia
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2016 2016 Overview of Overview of Forest Health Conditions Forest Health in Conditions in Southern British Columbia Southern B.C. Ministry of Forests, Lands, and Natural Resource Operations Prepared by: Lorraine Maclauchlan Kevin Buxton Table of Contents Introduction..................................................................................................................................... 3 Area Summary of Major Disturbance Agents......................................................................... 4-6 Southern Interior Overview........................................................................................................... 7 Mountain Pine Beetle.............................................................................................................. 7 Western Pine Beetle................................................................................................................. 8 Douglas-fir Beetle.................................................................................................................... 8 Spruce Beetle........................................................................................................................... 9 Western Balsam Bark Beetle................................................................................................... 9 Bark Beetle Training Sessions................................................................................................ 10 Insect Defoliators - General.................................................................................................... 11 Western Spruce Budworm....................................................................................................... 11 Douglas-fir Tussock Moth and Other Low Elevation Defoliators........................................... 15 Western Hemlock Looper........................................................................................................ 20 Gypsy Moth............................................................................................................................. 20 Needle Diseases....................................................................................................................... 20 Other Tree Diseases................................................................................................................. 21 Bear Damage........................................................................................................................... 22 Aspen Decline......................................................................................................................... 22 Wildfire.................................................................................................................................... 22 Drought.................................................................................................................................... 22 Other Damage.......................................................................................................................... 22 Summaries by Timber Supply Area............................................................................................... 23 Kamloops TSA........................................................................................................................ 23 Merritt TSA............................................................................................................................. 25 Lillooet TSA............................................................................................................................ 26 Okanagan TSA........................................................................................................................ 27 Quesnel TSA........................................................................................................................... 29 Williams Lake TSA................................................................................................................. 30 100 Mile House TSA............................................................................................................... 31 Selkirk South: Arrow, Boundary, and Kootenay Lake TSAs.................................................. 33 Selkirk North: Golden and Revelstoke TSAs.......................................................................... 35 Cranbrook and Invermere TSAs.............................................................................................. 36 Forest Health Special Projects........................................................................................................ 37 Monitoring Forest Productivity: An International Network..................................................... 37 Five Needle Pine Conservation in the ‘Crown of the Continent’............................................ 39 Whitebark Pine: Preparing to Plant......................................................................................... 40 Blister Rust Resistance Screening Trials: Interpretive Signs Installed.................................... 41 Mortality Factors of Subalpine Fir: Western Balsam Bark Beetle and Subalpine Fir Weevil...................................................................................................... 42 Status of Balsam Woolly Adelgid in the Southern Interior...................................................... 51 Long-Term Spacing Trials in Lodgepole Pine......................................................................... 54 Recent Forest Health Publications........................................................................................... 60 Ministry of Forests, Lands and Natural Resource Operations, Kamloops, B.C. 2 Introduction This report summarizes the results of the 2016 Aerial Overview Surveys, forest health operations, and research projects conducted in the southern interior of British Columbia. The aerial overview survey is performed annu- ally by the B.C. Ministry of Forests, Lands and Natural Resource Operations (FLNR) and details forest damage due to bark beetles, defoliators, and other visible forest health factors, such as foliar diseases and abiotic damage. Surveys were carried out using the standardized Provincial Aerial Overview Survey protocols (http://www2.gov. bc.ca/gov/content/environment/research-monitoring-reporting/monitoring/aerial-overview-surveys/methods). Polygons are used to record larger areas of continuous damage, and are assigned severity ratings as described in Table 1. Spots are used to record small, discrete groups of affected trees. The 2016 surveys were completed between July 14th and August 19th, 2016. A total of 261.6 hours of fixed-wing aircraft flying time over 54 days were required to complete the surveys, which covered all areas within the Cari- boo, Thompson Okanagan, and Kootenay Boundary Natural Resource Regions. These three regions cover more than 25 million hectares, of which over 15 million hectares are forested. Flying conditions were generally good, with relatively few days lost due to weather or wildfire smoke. Just over one million hectares of damage were mapped during the surveys. Bark beetles were the most common and widespread damaging agents, with affected area up by 70% to 580,000 hectares. Defoliators were the second most widespread damage agents, at 405,000 hectares. Other disturbances, such as foliar diseases, animal dam- age, declines, wildfire, drought, windthrow, and other abiotic agents, caused damage on another 50,570 hectares (Table 2). Table 1. Severity ratings used in the aerial overview surveys. Two main types of severity ratings are used. Bark beetles and other direct mortality-causing agents are rated based on the percentage of recently killed trees in the stand. Defoliators (both insect and disease) are rated based on the severity of foliage loss. Disturbance Type Severity Class Description Tree Mortality Trace < 1% of trees in the polygon recently killed (including bark beetles, Light 1-10% of trees in the polygon recently killed abiotic factors, Moderate 11-29% of trees in the polygon recently killed and animal damage) Severe 30-49% of trees in the polygon recently killed Very Severe 50% + of trees in the polygon recently killed Defoliation* Light some branch tip and upper crown defoliation, (including defoliating insect barely visible from the air and foliar disease damage) Moderate thin foliage, top third of many trees severely defoliated, some completely stripped Severe bare branch tips and completely defoliated tops, most trees sustaining >50% total defoliation Decline Syndromes** Light decline with no mortality - the first detectable stage, characterized by thin crowns and no individuals without visible foliage. Moderate decline with light to moderate mortality - thin crowns are accompanied by individuals devoid of foliage. Greater than an estimated 50% of individuals have some foliage. Severe decline with heavy mortality - crowns are very thin and greater than 50% of standing stems are devoid of foliage. * Serpentine leafminer defoliation is rated according to the percentage of trees in the stand that are affected, based on tree mortality classes. ** Decline syndrome severity ratings developed from USDA Sudden Aspen Decline rating criteria. Ministry of Forests, Lands and Natural Resource Operations, Kamloops, B.C. 3 Table 2. Area summaries for forest health factors mapped during the 2016 aerial overview surveys. Timber Supply Area Area of Infestation (hectares) and Damaging Agent Trace Light Moderate Severe Very Severe Total