2011 Overview of Forest Health for Southern British Columbia 2011
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Summary 2011 Overview of Forest Health of Aerial for Southern British Columbia Overview Surveys for Southern B.C. 2011 Prepared by: Kevin Buxton Lorraine Maclauchlan Michael Murray Table of Contents Introduction..................................................................................................................................... 3 Area Summary of Major Disturbance Agents...................................................................... 4-6 Map of 2011 Mountain Pine Beetle Infestations.................................................................. 7 Map of Beetle Management Units and Management Strategies.......................................... 7 South Area Overview.......................................................................................................................... 8 Mountain Pine Beetle.......................................................................................................... 8 Douglas-fir Beetle................................................................................................................ 11 Spruce Beetle....................................................................................................................... 11 Western Balsam Bark Beetle............................................................................................... 11 Western Spruce Budworm................................................................................................... 12 Western Hemlock Looper.................................................................................................... 13 Douglas-fir Tussock Moth................................................................................................... 13 Two-Year Cycle Budworm.................................................................................................. 14 Aspen Serpentine Leaf Miner.............................................................................................. 14 Forest Tent Caterpillar......................................................................................................... 14 Larch Needle Blight............................................................................................................ 14 Birch Leaf Miner................................................................................................................. 15 Gypsy Moth......................................................................................................................... 15 Pine Needle Sheath Miner................................................................................................... 15 Larch Casebearer................................................................................................................. 15 Satin Moth........................................................................................................................... 15 Dothistroma Needle Blight.................................................................................................. 15 Aspen Decline..................................................................................................................... 16 Windthrow........................................................................................................................... 16 Wildfire................................................................................................................................ 16 Other.................................................................................................................................... 16 District Summaries......................................................................................................................... 17 Arrow Boundary District..................................................................................................... 17 Columbia District................................................................................................................ 20 Rocky Mountain District..................................................................................................... 21 Kootenay Lake District........................................................................................................ 23 Kamloops District................................................................................................................ 25 Headwaters District............................................................................................................. 29 Cascades District.................................................................................................................. 31 Okanagan Shuswap District................................................................................................. 33 Quesnel District................................................................................................................... 36 Central Cariboo District...................................................................................................... 37 Chilcotin District................................................................................................................. 39 100 Mile House District...................................................................................................... 40 Forest Health Special Projects....................................................................................................... 41 2011 Western Spruce Budworm Program Summary Report................................................ 41 2011 Douglas-fir Tussock Moth Program Summary Report................................................ 47 Western Hemlock Looper in the South Area......................................................................... 57 Defoliator Treatment Plans For 2012.................................................................................... 62 Mountain Pine Beetle Impact to Young Pine on TFL 35....................................................... 63 Western Balsam Bark Beetle Long Term Monitoring............................................................ 68 Forest Pathology Update....................................................................................................... 72 Ministry of Natural Resource Operations, 441 Columbia Street, Kamloops, B.C. 2 INTRODUCT I ON This report summarizes the results of the 2011 Aerial Overview Surveys for the southern interior of British Co- lumbia. These surveys are performed annually by the B.C. Forest Service, Ministry of Forests, Lands and Natural Resource Operations (MFLNRO) and document forest damage due to bark beetles, defoliators, and any other visible forest health factors, such as foliar diseases and abiotic damage. Surveys were carried out using the stan- dardized Provincial Aerial Overview Survey protocols (http://www.for.gov.bc.ca/hfp/health/overview/methods. htm). Table 1 describes severity ratings used in the surveys. The 2011 surveys were completed between July 11 and August 20, 2011. A total of 281.5 hours of fixed-wing aircraft flying in 57 separate flights were required to complete the surveys, which covered the entire landbase of the Cariboo, Thompson Okanagan, and Kootenay Boundary Natural Resource Regions. Flying conditions were generally good, although some delays were experienced due to cloudy, wet weather. Unseasonably cool weather during the spring and early summer slowed the development of some damage signatures. As a result, detection of mountain pine beetle attack was more difficult and possibly underrepresented in some areas. Conifer defoliating insects were the most commonly mapped damage, totaling 630,000 hectares. Bark beetles affected 176,500 hectares, and were the most prevalent tree mortality factor and cause of volume loss. Other major damage types were insect defoliators of deciduous trees (nearly 96,000 hectares) and needle diseases (over 33,000 hectares). An assortment of other disturbances, such as root diseases, animal damage, declines, and abiotic agents such as wildfire, caused damage on another 4,360 hectares (Table 2). In 2011, realignment of the Natural Resource Regions resulted in some organizational changes to some Districts. The southern portion of the Headwaters District which is within the Kamloops Timber Supply Area, was re-aligned with the former Kamloops District and renamed the Thompson Rivers District, within the Thompson Okanagan Natural Resources Region. The northern portion of the Headwaters District is now part of the Omineca Region. Similarly, the Arrow Boundary, Columbia, and Kootenay Lake Districts were functionally realigned into a single Natural Resources District, the Selkirk District. For the purposes of this report, the results of the aerial overview surveys will be reported out using the original pre-2011 District organizational units to facilitate easier compari- son to previous years (Headwaters District results will represent the southern portion of the District only). No changes were made to the District boundaries in the Cariboo Natural Resources Region. Table 1. Severity ratings used in the aerial overview surveys. Two 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 Trace < 1% of trees in the polygon recently killed Tree Mortality Light 1-10% of trees in the polygon recently killed (including bark beetles, Moderate 11-29% of trees