Helping Chinese researchers develop alternatives to clearfell management systems for upland conifers
Liaoning Province lies about halfway between Beijing and the North Korean border. My visit focused on helping researchers at the Liaoning Institute to undertake some basic research into Korean pine (Pinus koraiensis) stands; to establish, photograph and analyse a series of Korean pine plots with a view to finding new ways of managing the stands, for example to improve their natural regeneration.
By working on-site with the researchers, we helped train them in the use of hemispherical camera equipment and associated analysis software, which in FR we use to establish the relationships between stand basal area, an indicator of stocking density, and the below-canopy light environment.
LIFM’s plant nursery and research outstation for their Korean pine plantations lies to the north in Caohekou. These plantations look very similar to equivalent-aged Scots pine plantations in Scotland. The sites are thinned at irregular intervals, removing sufficient trees for commercial use, but leaving sufficient stock to perpetuate the stand until clearfell. However, there is now pressure for these forests to be managed for multi-purpose objectives, with an irregular stand structure and more diverse species.
Although originally planted for timber, the seeds from Korean pine are a valuable resource in an area where the local population is mostly made up of farmers living on what they can grow or harvest from the natural environment. The seeds contain high levels of vitamins A and E, as well as oleic and linoleic acids and are often worth more than the commercial value of the trees. As a result, they are collected by anyone who can access the trees, reducing the sites’ ability to regenerate. We did see some natural regeneration however, despite the removal of most of the cones — in one area of the forest, a seed stand of improved (wood) quality Korean pine has been established. Beside the stand, a wooden platform has been erected within the branches of a big larch tree; for three months before the seeds ripen, a local man is employed to live there armed with a shotgun to warn off any potential illegal seed collectors.
For my research work, we choose ten plots for assessment and photographed them at 5.30 a.m. — just before sunrise to get the best quality photography. In Scotland the forests are quiet, restful places at this time of day, but in China they’re alive with the yells and cries of locals exercising; some practice Tai Chi, some Kung fu, and others are out for a brisk backwards walk or run before work.
The initial results from these ten plots indicated broadly similar light transmittance values in Korean pine plantations to those of comparable basal area in Scots pine plantations in Scotland. These results are being used by LIFM researchers to design suitable management systems to achieve their multiple objectives for the sites.
Overall, it was a valuable opportunity to share our expertise and I visited a range of sites to learn about the issues challenging foresters in China, including the social and economic pressures that affect their work.