Contingent valuation of the Natura 2000 nature conservation programme in Finland   总被引：2，自引：0，他引：2  

Pouta  E.; Rekola  M.; Kuuluvainen  J.; Tahvonen  O.; Li  C.-Z. 《Forestry》2000,73(2):119-128

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Synergistic interactions between a variety of insecticides and an ergosterol biosynthesis inhibitor fungicide in dietary exposures of bumble bees (Bombus terrestris L.)          下载免费PDF全文

Risto Raimets  Reet Karise  Marika Mänd  Tanel Kaart  Sally Ponting  Jimao Song  James E Cresswell 《Pest management science》2018,74(3):541-546

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Impact of Re-wetting of Forestry-Drained Peatlands on Water Quality—a Laboratory Approach Assessing the Release of P,N, Fe,and Dissolved Organic Carbon     

Annu Kaila  Zaki Asam  Markku Koskinen  Risto Uusitalo  Aino Smolander  Oili Kiikkilä  Sakari Sarkkola  Connie O’Driscoll  Veikko Kitunen  Hannu Fritze  Hannu Nousiainen  Arja Tervahauta  Liwen Xiao  Mika Nieminen 《Water, air, and soil pollution》2016,227(8):292

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Seasonal dynamics of wood formation: a comparison between pinning,microcoring and dendrometer measurements   总被引：1，自引：1，他引：0  

Harri Mäkinen  Jeong-Wook Seo  Pekka Nöjd  Uwe Schmitt  Risto Jalkanen 《European Journal of Forest Research》2008,127(3):235-245

Three different methods were evaluated for analysing wood formation of Norway spruce [Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) in Finland. During two growing seasons, wood formation dynamics were determined both by wounding the cambium with a needle followed by localisation of the wound-associated tissue modification after the growing season (pinning), and by extracting small increment cores during the growing season (microcoring). Stem radius was additionally monitored with band dendrometers. For Norway spruce, pinning and microcoring yielded similar dates for the onset of wood formation. The timing of wood production during the growing season was also similar for pinning and microcoring. For Scots pine, the onset of wood formation was recorded from microcores almost 2 weeks later than from pinning samples. In Scots pine, microcore measurements also produced somewhat later cessation dates for tracheid formation than the pinning samples. For both tree species, the total number of tracheids formed during the growing season was, however, about the same for pinning and microcoring. Dendrometer results clearly differed from those of pinning and microcoring. In particular, the dendrometers showed an increase of stem radius considerably earlier in spring, when the other methods did not detect wood formation. Thus, pinning and microcoring currently represent the most reliable techniques for detailed monitoring of wood formation.  相似文献   

Projected large-scale range reductions of northern-boreal land bird species due to climate change     

Raimo Virkkala  Risto K. Heikkinen 《Biological conservation》2008,141(5):1343-1353

Climate change is projected to be particularly strong in the northern latitudes. Thus, boreal or arctic species are especially susceptible to the effects of climate warming. In this work we forecasted changes in the distributions of 27 northern land bird species in the 21st century, based on predicted rates of climate change. We used climate and bird atlas data of Finland and northern Norway from 1971-1990 to establish bioclimatic envelope models for each species. Next, these models were applied to two climate scenarios (A2 and B1) from the general circulation model HadCM3 to forecast potential future distributions of the study species over a larger area also covering parts of nearby Sweden and Russia. This area stretches through the boreal and continental arctic zone in northern Europe. In the A2 scenario the predicted global change in mean temperature is 3.8 °C by 2100 and in the B1 scenario 2.0 °C. Our results suggest that most of the northern land bird species will lose most of their climatic space by 2080 both in the more severe (A2, average predicted range decline: -83.6%) and in the less severe scenario (B1, average change: -73.6%). A large proportion (over two thirds) of the species considered here is thus susceptible to major range contractions in this geographical region. These climate change-induced threats are of importance because the Arctic Ocean represents a natural barrier for northward movement of species. To reduce the negative effects of climate change on the northern species, relatively large areas of continuous habitats in a connected reserve network should be preserved.  相似文献   

Pilodyn在桉树活立木材性质评估中的应用   总被引：1，自引：0，他引：1  

吴世军  徐建民  李光友  陆钊华  李宝琦  王伟 《林业研究》2010,21(1):68-72

测定了建立在广西22个4年生桉树无性系的Pilodyn值、木材基本密度、边材木材密度、心材木材密度和弹性模量。结果表明：Pilodyn值为9．44—15．41mm、木材密度为0．3514-0．4913g·cm^-3、弹性模量在3．94GPa到7．53GPa之间;Pilodyn值在不同处理、不同方向及不同参试无性系间均存在极显著差异。Pilodyn值与各材性指标间的相关系数在-0．433到-0．755之间,呈显著到极显著负相关。研究表明,Pilodyn方法可以预测桉树活立木的木材密度和弹性模量。  相似文献   

The effect of girdling on the moisture content of small-sized trees     

Jussi Laurila  Risto Lauhanen  Tuomas Hakonen 《Scandinavian Journal of Forest Research》2014,29(3):259-265

In this study, the effect of girdling on the moisture content of small-sized trees for heat energy production was clarified. The moisture content was measured for Scots pine (Pinus sylvestris), Norway spruce (Picea abies), and Downy birch (Betula pubescens) during two growing seasons after girdling. The trees were girdled at breast height for around 30 cm by removing the bark, phloem, and cambium from around the stem. At the beginning of the growing season the mean moisture content of the living Scots pine (P. sylvestris) and Norway spruce (P. abies) was 60%, and for Downy birch (B. pubescens) it was 50%. During the first growing season the effect of girdling on the moisture content was low, but during the second growing season the moisture content decreased significantly. The moisture content of the Norway spruce (P. abies) (23%) and Downy birch (B. pubescens) (33%) was at its lowest point at 14 months after girdling. There were no significant changes in the moisture content of the Scots pine (P. sylvestris) in this study. The results of this study can be used in basic research and in the development of energy wood production.  相似文献