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EXperimental Design Protocol for Long-term Operational Response Evaluations: EXPLORE
|Project Leader(s):||Balvinder Biring and Phil Comeau, B.C. Ministry of Forests, Research Branch, Victoria|
Over the 15 year period from 1981 to 1995 a total of 586 672 hectares of Crown forest land received brushing treatments at a cost of approximately $243 million. Approximately 75 000 hectares of forest land require brushing treatments each year. Some information is available on the short-term (2-3 year) impacts and benefits of commonly used treatments in reforested clearcuts. However, little information is available on the long-term effects of vegetation management practices on achievement of management objectives, including free-growing, green-up, stand development, growth, or yield objectives, especially under different silvicultural systems. Better information is required on how common practices affect biodiversity and habitat values to provide a basis for evaluating and selecting treatment options. There is also a critical need to examine the value and impacts of vegetation management treatments applied in a range of silvicultural systems, particularly systems that involve various levels of canopy retention.
The EXperimental design Protocol for Long-term Operational Response Evaluations (EXPLORE) provides a methodology for establishing long-term studies to document impacts of vegetation management and mixedwood management strategies. In each installation, at least one pair of plots (consisting of an untreated control or legacy plot and a treatment plot) is established. Replication is achieved by applying each treatment at several different installations. The option to establish additional plots for additional treatments is provided for in the protocol. Each EXPLORE installation consists of at least two 70 m x 70 m (0.49 ha) treatment units, where one is an untreated control unit and the other a treated unit (Figure 1). This is viewed as a minimum size (0.49 ha) for each treatment unit. One circular 0.10 ha (17.84 m radius) Permanent Measurement Plot (PMP) is established at the centre of each treatment plot to provide a permanent fixed area sample plot for EXPLORE measurements. In the case of a strip-cutting silvicultural system, two circular PMPs are centered on the boundaries between cut and uncut strips (one on each boundary), to document both treatment and edge effects. In the case of dense coniferous or mixedwood stands, smaller PMPs >0.04 ha (>11.28 m radius) are established for tree measurements. The PMP is subdivided into four equal quadrants to facilitate accurate stocking measurements and to better cover the entire PMP. Four circular 0.005 ha (3.99 m radius) Regeneration Measurement Plots (RMPs) nested within each quadrant of the PMP are used to assess minimum and target stocking of preferred and acceptable species, free-growing status of crop tree species. Centre points of the RMPs are located 10.50 m from the centre of the PMP (0.1 ha) at bearings of (1) 45o, (2) 135o , (3) 225o and (4) 315o. Competitive effects of neighbouring vegetation on tree performance are assessed in 36 (0.001- 0.002 ha) tree centred Competition Measurement Plots (CMPs). Within each treatment unit, 36 crop trees are selected systematically by establishing a 50 m x 50 m grid at the centre of treatment unit. To measure the type and degree or severity of soil disturbance created by mechanical site preparation (MSP) equipment transect lines are located at 5 m spacing in a 50 m x 50 m grid in a treatment unit. To measure the amount of coarse woody debris (CWD) in each treatment, and to measure amount of slash load and the intensity of the burn in prescribed burning, 25 m transect lines are drawn from the centre of PMP. In each EXPLORE installation, data is collected to document: i) vegetation development; ii) growth of individual seedlings, saplings or trees; iii) stand dynamics; iv) stand structure; v) coarse woody debris; vi) soil disturbance; vii) plant species diversity; and, viii) growth and yield of crop trees.
This protocol provides the basis for obtaining needed information on the effects of silviculture practices on stand dynamics, growth and yield, and biodiversity. The network of installations established according to this protocol will provide information on the short-term and long-term impacts of silviculture practices including a) vegetation and mixture management; b) the impact of silviculture practices on crop growth and yield, and biodiversity; and, c) the impact of alternative silvicultural systems on forest regeneration and community diversity. EXPLORE installations will serve as demonstration sites for training, communication, planning and decision-making.
Biring, B.S., P.G. Comeau, J.O. Boateng, and S.W. Simard. 1998. Experimental design Protocol for Long-term Operational Response Evaluations (EXPLORE). Res. Br., B.C. Min. For.,Victoria, B.C., Working Paper 31/1998.
Biring, B.S., P.G. Comeau and J.O. Boateng. 1996. EXPLORE: Experimental Design Protocol for Long-term Operational Response Evaluations. In Expert Committee on Weeds: Proceedings of the 1996 National Meeting. B.C. Min. For., Research Branch, Victoria.
Biring, B.S., P.G. Comeau and J.O. Boateng. 1995. A vegetation management monitoring system for British Columbia. E.P. 1192. Working Plan. B.C. Ministry of Forests, Research Branch, Victoria
Support for this project has been provided by the B.C. Ministry of Forests and Forest Renewal BC.