Crown Morphology of Norway Spruce from Usual Tree Measurements

The crown morphology of Norway spruce (Picea abies Karst) was studied from 617 sample trees. In order to model branch and crown descriptors the linear and nonlinear regression methods were extensively used. Results show that the branch length can be fairly well predicted from the distance to the apex of the tree and that the branch spread has a high correlation with the branch length and the insertion angle. Models have been set up to predict the crown ratio, height to the base of the living crown, height to the first living branch and the height to the first dead branch from the usual whole-tree measurements, namely diameter at breast height total height and total age.

Examining approaches for modeling individual tree growth response to thinning in Norway spruce

Using periodic measurements from permanent plots in non-thinned and thinned Norway spruce(Picea abies(L.)H.Karst.)stands in Norway,individual-tree growth models were developed to predict annual diameter increment,height increment,and height to crown base increment.Based on long-term data across a range of thinning regimes and stand conditions,alternative approaches for modeling response to treatment were assessed.Dynamic thinning response functions in the form of multiplicative modifiers that predict no effect at the time of thinning,a rapid increase followed by an early maximum before the effect gradually declines to zero could not be fitted to initially derived baseline models without thinning related predictors.However,alternative approaches were used and found to perform well.Specifically,indicator variables representing varying time periods after thinning were statistically significant and behaved in a robust manner as well as consistent with general expectations.In addition,they improved overall prediction accuracy when incorporated as fixed effects into the baseline models for diameter and height to crown base increment.Further,more simply,including exponentially decreasing multiplicative thinning response functions improved prediction accuracy for height increment and height to crown base increment.Irrespective of studied attribute and modelling approach,improvement in performance of these extended models was relatively limited when compared to the corresponding baseline models and more pronounced in trees from thinned stands.We conclude that the largely varying and often multi-year measurement intervals of the periodic data used in this study likely prevented the development of more sophisticated thinning response functions.However,based on the evaluation of the final models’overall performance such complex response functions may not to be necessary to reliably predict individual tree growth after thinning for certain conditions or species,which should be further considered in future analyses of similar nature.

Norway spruce(Picea abies) laccases:Characterization of a laccase in a lignin-forming tissue culture

Secondarily thickened cell walls of water-conducting vessels and tracheids and support-giving sclerenchyma cells contain lignin that makes the cell walls water impermeable and strong. To what extent laccases and peroxidases contribute to lignin biosynthesis in muro is under active evaluation. We performed an in silico study of Norway spruce （Picea abies （L.） Karst.） laccases utilizing available genomic data. As many as 292 laccase encoding sequences （genes, gene fragments, and pseudogenes） were detected in the spruce genome. Out of the 112 genes annotated as laccases, 79 are expressed at some level. We isolated five fun-length laccase cDNAs from developing xylem and an extracellular lignin-forming cell culture of spruce. In addition, we purified and biochemically characterized one culture medium laccase from the lignin-forming cell culture. This laccase has an acidic pH optimum （pH 3.8-4.2） for coniferyl alcohol oxidation. It has a high affinity to coniferyl alcohol with an apparent Km value of 3.5μM; however, the laccase has a lower catalytic efficiency （Vmax/Km） for coniferyl alcohol oxidation compared with some purified culture medium peroxidases. The properties are discussed in the context of the information already known about laccases/coniferyl alcohol oxidases of coniferous plants.

Changes in fine root biomass of Picea abies forests:predicting the potential impacts of climate change

Aims the impact of global warming on belowground processes,espe-cially on fine root production,is poorly understood in comparison with its aboveground counterpart.Methods Here,we compiled 227 measurements to assess the influence of temperature and precipitation on fine root biomass of Norway spruce(Picea abies[L.]Karst)forest ecosystems in the Eurasia boreal region.Important Findings We found that fine root biomass decreased significantly with lati-tudes.there was a biomass increase of 0.63 Mg ha−1 and 0.32 Mg ha−1 for fine roots<2 and<1 mm in diameter,respectively,with 1°C increase of mean annual temperature.there was an increase of 0.5 and 0.1 Mg ha−1 per 100 mm year−1 precipitation for the two size classes of fine roots.If the adaption of root production can match the pace of global warming and water is not a limiting factor for plant growth,fine root biomass would be expected to increase by 40-140%in response to the predicted increase in tem-perature(3-10°C)over the next century.Our analyses highlighted the strongly positive influences of temperature and precipitation on belowground function,suggesting that predicted future climate change could substantially enhance belowground biomass in the boreal region where the greatest warming is anticipated.this potential increase of belowground biomass,coupled with aboveground biomass,may provide a better understanding of climate-ecosystem feedbacks.

细胞分裂素和硝酸铵对欧洲云杉不定芽伸长的影响(英文)

报道细胞分裂素和硝酸铵对欧洲云杉不定芽伸长过程的影响。采用5年生的欧洲云杉1个无性系不定芽丛来研究玉米素和硝酸铵对不定芽生长的影响。试验3种诱导类型(玉米素浓度分别为6·84、13·68、20·52μmol·L-1,激动素浓度0·69μmol·L-1,培养4周),玉米素最高浓度处理诱导的伸长芽数量最多,在4个无生长调节剂继代培养过程中,加入了1个硝酸铵浓度逐渐增加的继代培养过程。经不含生长调节剂的低浓度的硝酸铵(2·5mmol·L-1)培养基的继代培养后转入含有细胞分裂素的诱导培养基,下一个继代培养基补充的硝酸铵浓度分别为2·5、7·5、12·5、17·5mmol·L-1,8周(2个继代培养)后转入含有硝酸铵浓度为2·5mmol·L-1的培养基培养。硝酸铵浓度为7·5mmol·L-1的处理可形成数量最多的不定芽,这对于采用不同浓度的玉米素进行诱导的处理结果是一致的,但随着硝酸铵的浓度增至12·5mmol·L-1和17·5mmol·L-1时则不定芽的数量减少。欧洲云杉的胚轴外植体经1次或多次诱导后,细胞分裂素(BA、激动素、玉米素、2iP)促进了不定芽的分化和发育,其中BA由于可诱导产生大量的不定芽而成为最有效的细胞分裂素。玉米素虽然诱导不定芽相对弱一些,却在BA多次诱导后可促进芽的伸长。这对获得具有形成不定芽能力并可扩繁的芽丛非常重要。

Influence of environmental predispositions on temperate mountain forest damage at different spatial scales during alternating drought and flood periods:case study in Hruby Jeseník Mts.(Czech Republic)

Mountain forests are more prone to environmental predispositions(EPs)than submountain ones.While remote sensing of mountain forests enables instantaneous damage mapping,the investigation of the causes requires field data.However,a local field or regionally modeled environmental characteristics influence remote data evaluation differently.This study focused on the evaluation of EPs effects damaging mountain forests between various spatial resolutions during environmental change.The evaluation was divided into managed and natural forests in the Hruby Jeseník Mts.(Czech Republic;240-1491 m a.s.l.;50.082°N,17.231°E).Damage was assessed through the discrimination analysis of the normalised difference vegetation index(NDVI)by MODIS VI during alternating drought and flood periods 2003-2014.The local environmental influence was assessed using the discrimination function(DF)separability of forest damage in the training sets.The regional influence was assessed through map algebra estimated via the DF and a forest decline spatial model based on EPs from differences between risk growth conditions and biomass fuzzy sets.Management,EPs and soil influenced forest NDVI at different levels.The management afflicted the NDVI more than the EPs.The EPs afflicted the NDVI more than the soil groups.Strong winters and droughts had a greater influence on the NDVI than the flood events,with the winter of 2005/2006 inverting the DF direction,and the 2003 drought increasing differences in managed forest biomass and decreasing differences in natural forest biomasses.More than 50% of declining managed forests in the training sets occurred on Leptosols,Podzols and Histosols.On a regional scale,the soil influence was eliminated by multiple predispositions.The EPs influenced 96% of natural forest and 65% of managed forest,though managed forest damage was more evident.The mountain forest NDVI decline was dependent on both management and risk predispositions.