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Sandra Metslaid Allan Sims Ahto Kangur Maris Hordo Kalev Jõgiste Andres Kiviste Pertti Hari 《Journal of Forest Research》2011,16(3):237-243
There is strong evidence that climate change alters tree growth in boreal forests. In Estonia, the analysis of ring measurements has been a common method to study growth changes. In this study, annual height growth data from dominant or co-dominant Scots pine (Pinus sylvestris L.) trees were used to develop a growth model for three forest generations. Stem analysis was applied and annual height growth was measured as the distance between whorls, as detected by branch knots of whorls on the split stem surface. Retrospective analysis of height growth produced comparative trends for three different age groups. Statistical analyses were used to estimate the impact of different factors on growth. Annual height growth was considered the best indicator for detecting possible trends in the growth potential of trees. Study results indicate that three generations (separated by time periods of 30–40 years) showed significant differences in growth patterns caused by shifts in climatic factors and management regimes (anthropogenic and natural disturbances). 相似文献
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Ekaterina Shorohova Timo Kuuluvainen Ahto Kangur Kalev Jõgiste 《Annals of Forest Science》2009,66(2):201-201
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Abstract – The River Purtse was historically a significant Atlantic salmon spawning river in the Gulf of Finland (Baltic Sea). After the establishment of oil shale mining and processing in the catchment area in the late 1920s, the salmon population went extinct. By the 1970s, the river was heavily polluted and the lower reaches lacked any fish fauna. However, since the 1990s, pollution from oil shale mines was greatly reduced and water quality started to improve. The first fish species to repopulate the polluted area were gudgeon and nine‐spined stickleback. The first salmon parr from wild spawning were recorded in 2006. Up to 2009, a total of fifteen fish species have been recorded including trout and the sensitive bullhead. This study illustrates the natural recovery of the fish fauna following water quality improvement. 相似文献
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