长白山区林下可燃物含水率的观测特征和相关分析

森林可燃物的观测与研究对于火险等级的预报具有重要意义。笔者利用长白山区8个测站（每站6个测点）的观测资料和统计学方法,分析了林下可燃物含水率的变化特征。结果表明,林下可燃物的平均含水率为40%,大部分处于不易燃烧的状态,极易燃烧的情况只出现过1个站次,容易燃烧的天数占总数的12%。整个长白山区的林下可燃物含水率以及相同测站的不同站点的含水率在变化上具有很好的一致性。含水率与气象要素的分析表明,含水率与日最高气温、蒸发量、日照时数存在明显的联系,与观测前3天的累积降水量具有很好的相关性。     

Fine-scale species co-occurrence patterns in an old-growth temperate forest

The pattern of species co-occurrence is instrumental for understanding community assembly rules. In this paper, we analyzed the co-occurrence of tree species in a 25-ha old-growth temperate forest plot in Northeastern China. The analysis was conducted at seven scales from 5 m × 5 m up to 100 m × 100 m in order to determine the patterns of co-occurrence at different spatial scales. Our analyses were conducted for all species, species with larger abundances, species with larger sizes, and five phylogenetic-based species groups. Our results showed that at smaller scales, the co-occurrence patterns of all species, species with larger abundances, and species with larger sizes were significantly higher than expected by chance, suggesting that strong interspecies competition exists in the community. At larger scales, there was no significant difference compared to randomized matrices. The result indicated that plant assembly rules are only found at small spatial scales. However, when co-occurrence metrics were restricted to phylogenetic groups, we could not find any clear evidence of interspecific competition within these groups. In conclusion, we found that competition is an important assembly rule at small scales in governing tree communities of our temperate forest, although it is not the only process involved. The importance of other processes should also be taken into account to explain species co-occurrence patterns.     

双波长分光光度法测定土壤硝态氮的可行性研究

为了探寻简单、快速的土壤硝态氮测定方法,以指导农业生产氮肥施用,对双波长长法测定土壤硝态氮的方法进行了探讨,并与广泛应用的反射仪法和流动分析仪测定方法进行了比较,结果表明双波长分光光度法与反射仪测定和流动分析仪测定方法高度相关,操作简便、准确,可用于土壤硝态氮的测定。     

福寿螺在水稻田的消长规律及其田间分布动态

摘要：水稻田福寿螺成幼螺是以水为介质发生、入侵和扩散,消长规律随水稻对水的需求而动态变化,发生和危害在同一块田中存在一定的区域性;每年一般发生2—3代,其中早稻发生不完全1代或1代,晚稻发生1—2代,世代重叠;在早、晚稻生长期随时可见稻株上新产的卵块。     

肉鸡浸烫工艺参数的研究

浸烫是肉鸡屠宰加工过程中的一个关键作业工序,其效果好坏影响后续脱羽和去残羽效率和肉鸡产品品质。通过对浸烫工艺参数与浸烫效果之间相互关系的研究,获取最佳浸烫效果的工艺参数和烫后羽毛附着力。实验结果表明,样本肉鸡烫后主羽翼和主尾翼附着力为4N以下,纤羽附着力为2N以下时,非常适宜脱羽。采用旋转组合设计实验,获得样本肉鸡的最佳浸烫参数为:浸烫温度58.4℃,浸烫时间97s。     

逆境条件下植物CBL-CIPK信号途径转导的分子机制

非生物逆境条件下,植物细胞中的钙离子浓度会发生变化从而导致独特的钙信号的产生,钙信号通过与各种钙离子结合蛋白作用,从而将信号继续向下游传递.CBL蛋白作为近年来刚发现的一类钙结合元件,通过与一类丝氨酸/苏氨酸蛋白激酶-CIPK相互作用而形成了一套植物钙信号传递网络,并且在盐、干旱、低钾等非生物逆境的信号传递中起着重要作用.     

山西中南部盆地立地区造林模式研究——山西省立地类型划分与造林模式研究（Ⅹ）

在简要介绍中南部盆地立地区立地条件的基础上,提出了该立地区生态治理的思路,为其选择了50余个造林树种,并以立地类型亚区为单元配置了造林模式,共配置造林模式132种（每个立地类型亚区66种）,最后举例对造林模式进行了详细说明。     

Density dependence on tree survival in an old-growth temperate forest in northeastern China

? Density dependence is a major mechanism for shaping plant communities. However, its role in regulating diverse, mixed natural tree communities is less certain.

? In this study we investigated density-dependent effects in a large-scale (25 ha) old-growth temperate forest in northeastern China. Spatial patterns of neighborhood distribution in the plot were analyzed using various methods for inferring competition, including (1) pair correlation function to determine spatial patterns of pre-mortality and post-mortality and (2) neighborhood analysis of individuals to examine the extent to which tree survival is correlated with other covariates.

? Results showed that, for common species, 3 of 5 canopy species and 3 of 8 midstory and understory species were random in mortality. Negative density-dependent mortality was not found when trees reach 1 cm in DBH. There was no significant correlation for canopy species between tree survival and conspecific abundance, but largely positive correlations for midstory and understory species. In contrast, tree survival was found to negatively correlate with conspecific basal area for most species, indicating strong intraspecific competition. No strong interspecific density dependence was found in the forest.

     

纳米TiO_2改性竹炭和竹炭抑菌性能比较研究

用纳米TiO2分别对颗粒状及粉末状竹炭进行改性得到纳米改性竹炭,并对纳米改性竹炭(颗粒、粉末)、4种炭化温度(500℃、600℃、700℃和800℃)的竹炭及纳米TiO2共7种材料,在无光照条件下对2种霉菌(黑曲霉菌、绿色木霉菌)进行抑菌试验。结果表明:纳米TiO2改性竹炭(颗粒、粉末)抑菌效果最好,其防治效力(E)分别为90%和100%。4种炭化温度竹炭的防治效力(E)分别为25%、25%、25%和0%,纳米TiO2材料没有抑菌能力,其防治效力(E)为0%。试验表明,纳米TiO2改性竹炭比普通竹炭的抑菌效果好,是一种抑菌能力强的新型竹炭材料。     

高大平房仓空调控温储粮试验

通过分析储粮生态区的特点和影响储粮安全的生态因素,采用空调制冷为主要控温技术手段,并结合“四合一”储粮新技术,合理控制仓温粮温,实现准低温储粮。