不同分辨率图像合成的探讨

结合生产实践，通过对TM，Spot数据的分析。合理应用较高分辨率的全色波段，使假彩色合成的图像更加清晰，提高判读的正确率，为不同分辨率的图像合成提供解决办法。     

Comparison of satellite images with different spatial resolutions to estimate stand structural diversity in urban forests

The structural diversity in urban forests is highly important to protect biodiversity. In particular, fruit trees and bush species, cavity-bearing trees and coarse, woody debris provide habitats for animals to feed, nest and hide.Improper silvicultural practices, intensive recreational use and illegal harvesting lead to a decline in the structural diversity in forests within larger metropolitan cities. It is important to monitor the structural diversity at definite time intervals using effective technologies with a view to instituting the necessary conservation measures. The use of satellite images seems to be appropriate to this end. Here we aimed to identify the associations between the textural features derived from the satellite images with different spatial resolutions and the structural diversity indices in urban forest stands(Shannon–Wiener index, complexity index, dominance index and density of wildlife trees).Rapid Eye images with a spatial resolution of 5 m 9 5 m,ASTER images with a spatial resolution of 15 m 9 15 m and Landsat-8 ETM satellite images with a spatial resolution of 30 m 9 30 m were used in this study. The firstorder(standard deviation of gray levels) and second order(GLCM entropy, GLCM contrast and GLCM correlation)textural features were calculated from the satellite images.When associations between textural features in the images and the structural diversity indices were assessed using the Pearson correlation coefficient, very high associations were found between the image textural features and the diversity indices. The highest association was found between the standard deviation of gray levels(SDGLRAP) derived from RVIRAPof Rapid Eye image and the Shannon–Wiener index(Hh) calculated on the basis of tree height(R2= 0.64). The findings revealed that Rapid Eye satellite images with a spatial resolution of 5 m 9 5 m are most suitable for estimating the structural diversity in urban forests.     

Comparison of different control-pollination techniques for small-flowered eucalypts

Controlled pollination (CP) is a labour-intensive, but useful procedure applied in tree improvement programmes. However, the high costs involved and relatively low seed yields often obtained has, in most cases, necessitated the use of lower quality, open pollinated seed. The aim of the present study was to compare control-pollination methods for combinations among small-flowered eucalypt species. By making crosses within and among Eucalyptus grandis, E. smithii and E. macarthurii, we compared effectiveness, in terms of seed production and level of genetic contamination, of three CP techniques, namely emasculation of bagged flowers and subsequent pollination of receptive stigmas (Conventional method), emasculation and immediate pollination of stigmas with induced receptivity followed by bagging (One Stop Pollination), and pollination of cut styles without emasculation and bagging (Artificially Induced Protogyny). One tree of each species was used as the female in these crosses. Although Artificially Induced Protogyny using ripe and semi-ripe buds produced the highest seeds/flower pollinated in the majority of crosses carried out in this study, the technique, when performed on green buds, resulted in the highest capsule abortion. Molecular analysis using microsatellite markers also revealed that progeny from the Artificially Induced Protogyny method, when using green and semi-ripe buds, were highly contaminated by self- and external pollen. Of the three CP-techniques tested, One Stop Pollination had the lowest genetic contamination. However, this technique also had one of the lowest seed yields, while the Conventional method was intermediate in performance.     

Aspen regeneration on log decking areas as influenced by season and duration of log storage

This study assessed aspen regeneration on decking areas as affected by season of log deck building and duration of log storage; as well as root wounding, soil compaction, and slash depth. On former decking areas that were built after a summer harvest, aspen regeneration was 50% lower and root death 35% greater compared to former decking areas of a fall harvest. Duration of log storage after a fall harvest had little effect on aspen regeneration; short (1.5–3 months) or long (11 months) storage resulted in similar regeneration. Slash load was greatly increased on decking areas while root wounding and soil bulk density were only slightly increased compared to controls. For best management practices, log storage after summer harvest should be avoided especially when logs are kept over the growing period when suckering occurs. Additionally, removing the interwoven mat of slash covering decking areas and limiting machine traffic to frozen soil will ensure vigorous suckering.     

四种桉树青枯菌DNA提取方法及PCR检测灵敏度比较

以带有青枯菌Ralstonia solanacearum的桉树组织为材料,采用4种不同的提取方法抽提青枯菌DNA,同时利用青枯菌的特异性引物进行PCR扩增,比较了4种DNA的提取方法及PCR检测的灵敏度。结果表明,煮沸法和热裂解法操作相对简单,但检测灵敏度较低,检测限分别为104CFU/mL和103CFU/mL;简化提取法和试剂盒法检测效果较好,均可检测到102CFU/mL的青枯菌;简化提取法比试剂盒法操作更简单,检测成本低,具有更高的应用价值。     

摆满系数的研究

由于原木纵向选材输送机是在多点卸木条件下输送原木,所以,计算牵引构件最大张力值时。不能用充满系数而要用摆满系数来计算牵引构件上的原木载荷。摆满系数表示在单位时间内,一节输送机上的原木总长度与牵引构件总长度之比值。这个比值与楞头的位置排列、选材量大小和原木长短有关。一般可在0.23～0.38范围内选取。平均为0.31。     

提高原木出材率的工艺措施

生产实践经验表明，通过科学下锯、合理截断、合理使用锯条及科学合理地拼接板材等工艺措施，可以大幅度提高原木出材率，达到节约资源、高效利用的目的。     

Comparison of diameter-distribution-prediction,stand-table-projection,and individual-tree-growth modeling approaches for young red alder plantations

A red alder planting spacing study was used to compare three modeling approaches that have been successfully used for other tree species. These three approaches predict stand structure and dynamics in plantations that are 7 to 16 years old, with planting densities of 976 to 13 899 trees/ha. The diameter-distribution-prediction approach tended to over-predict the diameter at breast height (dbh) for larger trees in stands planted at low density and to under-predict dbh for smaller trees in stands planted at high density. This approach may be useful for comparing planting densities when a tree list is not available. The stand-table-projection approach tended to under-predict dbh for smaller trees in young stands planted at low density and to over-predict dbh for smaller trees in young stands planted at high density. This approach, however, provided consistency between stand- and tree-level growth projections, and should be useful for comparing planting densities when a tree list is available. The individual-tree-growth approach provided the best representations of observed diameter distributions at all planting densities, stand ages, and growth intervals. This approach may be best suited for stands that have been thinned, stands with mixtures of species, and stands with heterogeneous size classes.     

不同栽培模式对杜仲叶及枝皮中多种活性成分含量的影响

为了探寻不同栽培模式对杜仲叶及枝皮中多种活性成分含量的影响规律,以不同月份采集的吉首大学张家界校区校园内的杜仲矮林与乔林叶片与枝皮为试材,采用高效液相色谱法测定了其绿原酸、京尼平苷酸和松脂醇二葡萄糖苷的含量,采用硝酸铝-亚硝酸钠比色法测定了其总黄酮含量,还用对二甲氨基苯甲醛显色法测定了其桃叶珊瑚苷的含量。测定结果表明:7、9、10月采集的杜仲矮林叶中绿原酸的含量分别为2.416%、2.463%和2.934%,分别是同期采集的杜仲乔林的2.094、1.027和1.968倍;其总黄酮含量分别为1.224%、11.664%和14.564%,分别是杜仲乔林的0.159、0.759和1.146倍;其京尼平苷酸的含量分别为1.404%、1.012%和0.359%,分别是杜仲乔林的0.476、3.819和2.017倍;其桃叶珊瑚苷的含量分别为6.655%、6.543%和6.508%,分别是杜仲乔林的1.623、1.377和1.909倍。11月份采集的杜仲矮林枝皮中京尼平苷酸、桃叶珊瑚苷和松脂醇二葡萄糖苷的含量分别为6.711%、3.494%和0.467%,分别是杜仲乔林的1.035、2.024和1.052倍。测定结果还表明,杜仲矮林叶及枝皮中有多种活性成分的含量高于杜仲乔林,故矮林作业具有推广应用价值。     

管理创新理念在贮木场管理改革中的应用

本文论述了如何将管理创新的理念应用于贮木场具体的管理改革中 ,以及在管理创新的过程中还有那些不足和今后发展的趋势     

Comparison of four methods for the detection of Coleoptera adults infesting stored wheat: efficiency and detection sensitivity

In order to evaluate trapping and standard sampling methods for Coleoptera adult detection in bulked wheat, three commercial types of traps (WBII, Pitfall Cone Trap and Grain Probe Trap) and a 2-m long grain trier (9 openings, 750 g capacity) were compared. The comparison, which took place in 9 steel bins containing wheat in Central Greece, indicated that the traps were more effective in detecting adults belonging to the 21 beetle species that were found. Traps contained up to 45 times more adults than the grain trier samples, while at the same time traps produced noticeable levels of detection sensitivity for all species found, as compared to the grain trier samples. For most species, mean trap catches in WBII and Pitfall Cone traps were significantly higher than the means of the other two methods. The correlation coefficient values between trap catches and adult numbers in samples were not significantly different than zero, indicating that the effort to relate trapping to absolute estimation sampling methods is a very complex procedure.     

Effects of estimation length on parameter estimates of geometric Brownian motion for log price dynamics

We investigated an effect of the estimation length of the time-series data on the parameter estimates of geometric Brownian motion for log prices. This is to examine how much the estimates vary depending upon the estimation length of the data for the simulation purpose of stochastic modeling. Using the monthly time-series data for akamatsu, sugi, and hinoki from January 1975 to December 2000, our analysis shows that the longer the estimation length, the more stable the estimated value of the drift coefficient and the volatility coefficient of geometric Brownian motion become, implying less variability in the estimates needed for the simulation analysis. On the other hand, the shorter estimation length would tend to reflect such a sudden change in the data as the oil shock or the short-term decreasing or increasing tendency, which results in the large degree of variability in parameter estimates. This stems from the fact that the long estimation length regards a short-term price changes as an intrinsic part of price volatility. These results imply that when conducting a scenario analysis under stochastic environments, for the shorter estimation length, the wider range of parameter settings should be incorporated into the analysis.     

中国西南干旱河谷区植物多样性边界影响域的两种判定方法

研究了中国西南岷江上游干旱河谷区不同类型景观边界的影响域.共选取三种类型的边界.以植物多样性为基础,分别采用主成分分析法和移动窗口法对边界的影响域进行分析.结果表明, 5条样带中,主成分分析法可以判定3条样带的影响域,而移动窗口法可以判定4条.两种方法均可判定边界的影响域,并且影响域均在距边界50m内.在林地样带两种方法可以得出相似的结论,但在花椒地样带中所得结论不一致.两种方法比较,移动窗口法更成功些.虽然两种方法各有利弊,但它们都是刻画边界动态的有力工具.     

Feasibility of automatic detection of knots in maritime pine timber by acousto-ultrasonic scanning

In order to assess the lengthwise variation of mechanical properties of maritime pine (Pinus pinaster Ait.) a study on the possibility of automatically detecting knots by ultrasonic readings across the grain was carried out. A through-transmission acousto-ultrasonic (AU) setup was implemented allowing acquisition of AU profiles along the central mid-third of each specimen. An algorithm was proposed and successfully implemented for enhancing variations on the AU profiles due to knot presence. Discriminant analysis was applied to the AU profiles. The results show the possibility of automatically differentiating clear wood zones from zones with a knot area ratio value above 20% or 30%, with a success rate of 75% to 83% depending on the dimension of the specimens tested.This research project was supported by the Foundation for Science and Technology (FCT) under contract Nos. PBIC/C/AGR/2296/95 and POCTI/33967/AGR/2000     

The effect of taper on the MOE of log stringers

Load sharing between the stringers in gravel-decked log bridges is an important design factor when small- diameter stringers are used with thin gravel decks. In order to estimate the load sharing between the stringers, it is necessary to consider the deflection of the stringers; therefore, accurate estimates of the apparent modulus of elasticity (MOE) for full-size log stringers are required. In this paper, load and displacement data from the full- size bending tests are used to demonstrate that taper near midspan has the greatest effect on the MOE used in common log bridge design methods, where the logs are assumed to have constant cross sections. This paper proposes a method to estimate a MOE that can be used in a constant cross-section model given the geometry of the particular log of interest, and the MOE from full-size bending tests calculated when considering actual log geometry.     

3种山茶属植物花粉活力测定方法的比较

采用I-IK法、过氧化物酶法和TTC法对张氏红山茶、越南抱茎、南山茶新鲜花粉的活力进行了测定。3种方法测定的结果表明:3种花粉活力都在92.00%以上,南山茶的花粉活力最高,在90.20%~100.00%,越南抱茎茶次之在80.80%~99.40%,张氏红山茶在84.80%~96.00%。3种方法所测花粉活力存在显著差异或极显著差异。I-IK染色法所测花粉活力高于过氧化物酶法和TTC法所测花粉活力,此法染色快,并且染色清晰,可用于山茶花粉活力的快速测定;过氧化物酶法次之,TTC法所测花粉活力最小,这2种方法,染色需时长,而且染色不清晰,不适于快速测定山茶花花粉活力。     

如何强化与提高贮木场商品化管理水平

近几年，由于森工企业经济不景气，方正林业局从长远目标做起，做好贮木场商品化管理，挖潜增效，面向市场，提高了经济效益。