Age estimation of different tree species using a special kind of an electrically recording resistance drill

The determination of tree age is an important issue for urban green planning, forestry and dendrology; finding non-destructive and quasi-non-destructive methods for this purpose is of great theoretical and practical importance. The resistance drilling method is quasi-non-destructive because the average diameter of an opening that remains after drilling does not exceed 3 mm. Do electrically recording resistance drills allow precise assessment of tree age? The aim of this study is to assess the accuracy of determining the number of tree rings based on an examination of this special kind of drilling resistance profiles for three tree species, the pine Pinus sylvestris L., the oak Quercus robur L., and the birch Betula pendula ROTH. In 2015 and 2016, 15 pine trees, 15 oak trees, and 15 birch trees were randomly selected. For each studied tree, a measurement was conducted using the electrically recording resistance drill IML-Resi E400 with a flat-tipped 1.5/3 mm steel needle (research sample), and an increment core was taken (reference sample). The drill used was not a real Resistograph^®. The analysis of the E400-profiles underestimated the number of tree rings; the mean bias error (MBE) values were –6.5, –2.5, and –6.0 years for pine, oak, and birch, respectively. The proportion of investigated trees with less than five years difference between the research and reference samples varied from 38.4 (birch) to 66.7 (oak) percent. The accuracy of tree age determination was lowest for birch and highest for oak. The binomial generalised linear model (GLM) revealed that the most accurate tree age assessments were obtained from tree rings wider than 2 mm. The measurements clearly showed that the electrically recording resistance drill IML-Resi E400 enables a quick, although approximate, tree age assessment. Future research should concentrate on electronically regulating and recording drills, providing a higher spatial and signal resolution, and a stronger correlation to wood density.     

东北地区外来针叶树种引种现状及发展策略

介绍了东北林区主要针叶树种引种现状及取得的成就，分析了东北三省针叶树种引种工作中存在的问题，提出了建立较为科学的引种网络体系和发展策略，并提供了可能在干旱、半干旱区引种成功的针叶树种名     

冷季型草坪草建植管理技术研究

采用正交设计进行施肥里、刈割高度、播量，草坪草品种4因素4水平试验，通过测定草坪草越冬率，越夏率，成坪时间，叶绿素，杂草盖度，生长度，初步筛选出不同目的冷季型草坪草的建植管理方案。     

农业科研立题和成果鉴定的情报查新

阐述了农业科研立题,成果鉴定的情报查新的必然性及重要意义,并对查新工作提出了几点建议。     

四川乐山地区紫茎泽兰的入侵定殖和风险评估

本文报道了四川省乐山地区犍为县塘坝乡境内入侵新物种一紫茎泽兰的分布、发生和定殖入侵情况。结合紫茎泽兰的生物学特性和当地的地理气候特征，对紫茎泽兰入侵乐山及其近邻地区的风险进行评估。     

林木抗旱性生理指标及其在干旱区造林中应用研究

<正> 中国干旱半干旱区面积占全国面积的52.5%,半壁河山是以水分胁迫为主导限制因子的特殊生态区。为了提高这一地区的造林质量,选择旱生和抗旱性强的树种造林是主要造林技术之一。对于如何评价和比较林木的抗旱性,传统方法多采用对林木生态环境因子及对林木生     

菇木年龄对香菇产量和营养成份含量的影响

用南酸枣、秃瓣杜英、马褂木、麻栎、锥栗、枫香、银荆等7个优良菇木树种的不同年龄树木木屑作为栽培基质，选用126香菇品种做供试菌株，通过香菇总产量、冬菇产量、香菇营养物质含量的对比试验，结果表明，这7种菇木林树种7年树龄木屑栽菇香菇的性能优于或不低于15年成年树龄，用南酸枣、秃瓣杜英、马褂木、麻栎、锥栗、枫香、银荆作为经营短轮伐期菇木林树种是可行的。     

Landscape patterns as habitat predictors: building and testing models for cavity-nesting birds in the Uinta Mountains of Utah,USA

The ability to predict species occurrences quickly is often crucial for managers and conservation biologists with limited time and funds. We used measured associations with landscape patterns to build accurate predictive habitat models that were quickly and easily applied (i.e., required no additional data collection in the field to make predictions). We used classification trees (a nonparametric alternative to discriminant function analysis, logistic regression, and other generalized linear models) to model nesting habitat of red-naped sapsuckers (Sphyrapicus nuchalis), northern flickers (Colaptes auratus),tree swallows (Tachycineta bicolor), and mountain chickadees (Parus gambeli) in the Uinta Mountains of northeastern Utah, USA. We then tested the predictive capability of the models with independent data collected in the field the following year. The models built for the northern flicker, red-naped sapsucker, and tree swallow were relatively accurate (84%, 80%, and 75% nests correctly classified,respectively)compared to the models for the mountain chickadee (50% nests correctly classified). All four models were more selective than a null model that predicted habitat based solely on a gross association with aspen forests. We conclude that associations with landscape patterns can be used to build relatively accurate, easy to use, predictive models for some species. Our results stress, however, that both selecting the proper scale at which to assess landscape associations and empirically testing the models derived from those associations are crucial for building useful predictive models. This revised version was published online in July 2006 with corrections to the Cover Date.     

夏季狗牙根草坪不同建植方法及秋季交播黑麦草对成坪效果的影响

以狗牙根Cynodon dactylon种子和营养体为材料，在武汉地区，对5种不同建植方法建成的草坪从盖度变化、成坪时间、均一性、建植成本及秋季交播多年生黑麦草Lolium perenne后翌年狗牙根的草坪质量等方面进行综合比较。结果表明：采用夏季建植狗牙根草坪并于秋季交播多年生黑麦草的方法来建植四季常绿草坪，狗牙根采用撒茎覆沙法效果最佳，其他方法依次为开沟埋茎法、闻铺草皮法、穴植草茎法；种子直播法在翌年需重新建坪。     

高速公路边坡防护体系的建植养护

在对广东省普惠高速公路边坡生物防治体系——护坡草皮的建植和养护过程中，就草种选择、建植方式和质量监控等问题进行了讨论并提出建议，旨在提高我国高速公路边坡防护体系草皮的建植和养护水平。