Hofgaard Annika
Department of Forest Ecology, Swedish University of Agricultural Sciences S-901 83 Umeå, Sweden.
New Phytol. 1993 Nov;125(3):635-640. doi: 10.1111/j.1469-8137.1993.tb03913.x.
Short-term regeneration ability of a cold-marginal Picea abies forest was studied by analyzing spruce seed rain during nine years and by assessing resulting recruitment at the end of the studied period. Quantitatively large differences occurred between studied years, and seed viability was low during the whole study period. Only exceptionally did seed viability exceed 1 %. Sparse regeneration occurred in 1984, which is the year when most viable seeds/ha were recorded. In addition, the results are compared with recruitment data from the 1930s (from the same forest), a time period when regeneration peaked. It is suggested that the period 1984-1992, due to the sparse regeneration, retrospectively probably will appear as a regeneration trough or a decreasing regeneration trend. Furthermore, it is concluded that, in a long-term perspective, periodic regeneration is sufficient for maintenance of the forest because of the longevity of spruce. Additionally, climatically induced variations of regeneration success give rise to natural fluctuations in stand density.
通过分析九年期间的云杉种子雨，并在研究期结束时评估由此产生的幼苗更新情况，对寒冷边缘的欧洲云杉林的短期更新能力进行了研究。各研究年份之间在数量上存在很大差异，并且在整个研究期间种子活力都很低。种子活力仅在个别情况下超过1%。1984年出现了稀疏更新，这一年记录到了每公顷最具活力的种子数量。此外，将研究结果与20世纪30年代（同一森林）的幼苗更新数据进行了比较，那个时期更新达到峰值。研究表明，由于更新稀疏，1984 - 1992年这段时期在回顾时可能会呈现为一个更新低谷或更新下降趋势。此外，得出的结论是，从长期来看，由于云杉寿命长，周期性更新足以维持森林。此外，气候引起的更新成功率变化导致林分密度出现自然波动。
