Climate And Its Relevance To Lodgepole Pine Performance At The Sub Boreal Bednesti Research Site Over A 30 Year Period Ep0995

In 1988, three studies were established as part of Experimental Project 995 to study lodgepole pine (Pinus contorta var. latifolia) survival and growth responses to site preparation in the Sub-Boreal Spruce zone of north-central British Columbia. The project examines the effectiveness of several mechanical treatments and localized high-intensity burning, with a focus on disc trenching, which is the most commonly used mechanical site preparation technique in this region. The importance of disc trench orientation, planting aspect, and planting position were investigated, as well as potential interactions between broadcast burning and disc trenching. This report presents 25-year results for the Bednesti North and Bednesti South experiments, and 19-year results for the Tanli experiment. Treatment effects are discussed in relation to: lodgepole pine establishment (survival and early growth to age 5); performance at approximately free-growing age (9 years); and early mid-term growth, stand volume, and site index (as measured at age 25). Of the mechanical treatments tested, coarse mixing was the most effective, resulting in approximately 1-m gains in lodgepole pine height over the control at age 25. This treatment is not practical from an operational perspective, however, and the more common technique of disc trenching with trees planted at the hinge produced the second greatest gains. In contrast, pine planted in trench furrows showed a trend of reduced growth relative to the control. Trench orientation was relatively unimportant, but there was a slight advantage to avoiding north-aspect planting positions. Although broadcast burning alone did not have a significant effect on pine growth, it consistently interacted with disc trenching to produce a mild magnification of responses to that treatment. Pine planted in long, narrow, intensely burned windrow strips were consistently larger than control pine throughout the 25-year assessment period, but they had poor form due to being essentially open-grown.

Beginning in 1992, the British Columbia Ministry of Forests established a small network of lodgepole pine and interior spruce nutrient optimization research installations on representative sites within three major biogeoclimatic (BEC) zones in the British Columbia Interior. The objectives of the long-term "maximum productivity" study are to (1) compare the effects of different regimes and frequencies of repeated fertilization on the foliar nutrition, growth, and development of young interior forests, and (2) determine the effects of large nutrient additions on above- and below-ground timber and non-timber resources. This report examines the effects of repeated fertilization on foliar nutrition and tree- and stand-level growth and development over 12 years at the five lodgepole pine study sites.--Document.

Long-term data from established field experiments are required to properly evaluate different silvicultural options and to provide the basis for development and validation of growth models. Such data are available from a series of thinning and fertilization field studies established between 1941 and 1984 in lodgepole pine stands in the foothills of Alberta. These field sites span a wide range of ecological conditions and geographic locations. This report describes the locations and site characteristics of these these studies, their establishment histories and objectives, their experimental designs and treatments, and their results up to 2005.

This report describes & presents results of a retrospective study carried out between 1992 and 1999 in the Cariboo-Chilcotin region of British Columbia to quantify the effects of trembling aspen competition on lodgepole pine performance, and to identify competition indices or other measures of competition that could be used by field staff. Target pine were selected across neighbourhoods in six stands with varying densities of aspen. Data pertaining to pine size & condition, and to the size & location of aspen within a 70-inch radius of the pine were collected three times. Measurements began when the stands were seven to 12 years old. Various approaches are used to identify levels of aspen abundance when pine performance declined below acceptable levels. These include analyses of regression & correlation, tests of existing competition indices, and visual & statistical characterization of trends. Finally, conservative recommendations are made for the retention of aspen within pine stands in the Cariboo-Chilcotin region.