野鸦椿属植物的化学成分及药理作用研究进展

野鸦椿属植物的主要化学成分有三萜类、酚酸类、黄酮类、木脂素类、降倍半萜类等。现代研究表明该属植物的提取物及单体化合物具有抗炎、抗菌、抗肿瘤、抗肝纤维化等药理作用。目前,野鸦椿属植物分类发生了变动,不同品种之间的化学成分是否存在差异尚不十分明确。通过对野鸦椿属植物化学成分、药理作用进行系统检索和归纳总结,深入阐述不同品种之间化学成分是否存在差异及可能存在的差异成分,以期为野鸦椿属植物分类和开发利用提供参考。     

2种野鸦椿的生长适应性与栽培对比研究

以落叶类野鸦椿与圆齿野鸦椿为研究对象,在人工栽培下比较物候期、生长量、果实产量等方面的差异,结果表明2种野鸦椿物候期与生长适应性差异极大。圆齿野鸦椿四季常青,挂果期超长,而落叶类野鸦椿冬季落果落叶;圆齿野鸦椿适生在海拔700 m以下,而落叶类野鸦椿适合生长在700 m以上。在海拔较高的地区,落叶类野鸦椿长势较好,圆齿野鸦椿长势较差且出现冻死现象;在低海拔地区,圆齿野鸦椿长势较好,其生长指标与果实产量均显著高于落叶类野鸦椿。     

施微肥对野鸦椿幼树果叶生长和观赏性的影响

以8 a林龄野鸦椿为试验材料,在统一施用氮磷钾复合肥为基肥的基础上,分别增施硼、锌、锰微肥,探究硼、锌、锰三种微肥对野鸦椿果叶生理特性及观赏品质的影响。结果发现:增施锰肥有利于提高野鸦椿叶片的叶绿素含量;增施微肥可提高野鸦椿的抗逆性、促进果实膨大,提高产量,但对酶活性的影响并不明显。通过评价发现施微肥有利于提高野鸦椿观赏性,提高园林景观价值,因此,在野鸦椿栽培和园林应用中可适当施用微肥。     

遮光对野鸦椿幼苗生长和光合生理特性的影响

为了解不同光照条件下野鸦椿幼苗的生长发育状况和光合生理特性,探讨野鸦椿幼苗生长发育的最佳光照条件.采用遮光方式模拟不同光照强度(全光照,遮光30％、60％和90％),研究野鸦椿幼苗的生长、生物量、光合色素含量、生理指标和光合日变化等光合特性的响应规律.结果表明:随着遮光程度的增加,野鸦椿幼苗的生长量均高于对照,以遮光6...     

野鸦椿种子不同基质催芽及苗木密度试验

野鸦椿种子采收后去蜡处理,采取随采随播、湿沙贮藏(催芽)至第3年春播种、湿沙贮藏(催芽)至第2年春再转入林地腐殖土(催芽)至第3年春播种试验;并将催芽处理的种子进行不同密度播种试验,比较苗木生长量和质量、产量。结果表明:随采随播的种子发芽率最低,仅为6.7%,后2种贮藏(催芽)处理的种子发芽率均较高,分别达81.1%、78.7%;不同密度播种以株行距8 cm×10 cm的苗木质量、产量较适宜,苗木生长整齐,平均地径、苗高、主根长度、≥5 cm长Ⅰ级侧根数分别达0.65 cm、35.5 cm、20.6 cm、22.7条;平均苗木产量达73.75万株·hm~(-2)。     

不同基肥对圆齿野鸦椿幼苗生长的影响及其培育技术

采用沙藏催芽法对圆齿野鸦椿种子进行催芽处理,研究了出芽后2种基肥对该树种幼苗的苗高和地径生长的影响,探讨了其育苗技术.结果表明:圆齿野鸦椿出苗整齐后2.5～5.5个月,其以有机肥为基肥的苗高增长量显著高于以复合肥为基肥的苗高增长量;出苗整齐后1.5～7.5个月,以有机肥为基肥的幼苗地径增长量显著高于以复合肥为基肥的幼苗.有机肥能够更好地促进圆齿野鸦椿苗高和地径的生长.     

基质与植物生长调节剂对圆齿野鸦椿扦插生根的影响

2016年在福建省洋口国有林场来舟管护站堆头苗圃,以圆齿野鸦椿当年生半木质化枝条为插穗,研究扦插基质与植物生长调节剂种类、浓度、浸泡时间对圆齿野鸦椿扦插生根质量的影响。结果表明：扦插基质是影响扦插生根率、≥5 cm的Ⅰ级侧根数、最长Ⅰ级侧根根长的最主要因素;植物生长调节剂种类与浓度对扦插生根率、最长Ⅰ级侧根根粗影响显著;植物生长调节剂浸泡时间主要影响扦插生根率。依据生根质量指数筛选出2个适宜圆齿野鸦椿扦插生根基质与植物生长调节剂组合方案：以黄心土∶素沙(2∶1)为基质,ABT 50 mg·L^-1溶液浸泡插穗180 min;以黄心土为基质,NAA 50 mg·L^-1溶液浸泡插穗360 min。生根率、≥5 cmⅠ级侧根数、最长Ⅰ级侧根长、最长Ⅰ级侧根根粗分别在65.5%、3.73条、4.36 cm、1.48 mm以上。     

野鸦椿主要经济性状遗传参数估算及优良家系选择

野鸦椿(Euscaphis japonica)12个表型优良单株的半同胞子代测定结果表明:野鸦椿表型优良单株的半同胞子代家系间在单位面积果实产量、果穗长度、穗重、单穗果数等方面存在着显著或极显著差异;果穗长度、穗重、单穗果数、单位面积果实产量4个性状家系遗传力和单株遗传力都较高,性状间有明显的线性相关。通过方差分析、相关分析和聚类分析等方法,对各初选植株半同胞子代家系间的单位面积果实产量、果穗长度、穗重以及单穗果数分析比较,从初选的12个家系中进一步选择出经济性状表现优良的N1、N2、N5、N6、S1、S2、S3等7个优良家系。     

配方施肥对圆齿野鸦椿幼苗形态和叶片生理指标的影响

为研究氮磷钾配方施肥对圆齿野鸦椿幼苗形态和叶片生理指标的影响,以1年生圆齿野鸦椿盆栽苗为研究对象,采用正交设计L9(33)研究N、P、K不同配比施肥对幼苗生长和叶片可溶性蛋白、可溶性糖及叶绿素含量等生理指标的影响.结果表明:配方施肥可以改善苗木的生长特性,优化苗木的生理指标.其中,处理5的苗高、地径增长量和可溶性糖积累量最高,分别为72.67％、130.44％、6.94％,处理3的叶绿素含量最高,为37.17 mg·g-1,处理1的生物量和可溶性蛋白累积量最高分别达到7.52 g和45.02 mg·g-1.分析可知N、P、K配比保持在中低浓度对生理指标改良促进效果较好,有利于提高圆齿野鸦椿幼苗的各方面质量.     

圆齿野鸦椿YABBY基因家族鉴定及功能分析

YABBY基因家族在叶片、花器官、果实等生长发育方面具有调节功能。为了明确圆齿野鸦椿YABBY基因家族成员的基本特征,利用生物信息学手段对圆齿野鸦椿YABBY基因家族进行鉴定及功能分析。结果表明：在圆齿野鸦椿基因组中共鉴定出9个YABBY基因,非均匀分布在5条染色体上,通过系统发育树将其划分为5个亚族：FIL/YAB3、INO、YAB2、YAB5和CRC,多数基因有8个内含子。圆齿野鸦椿YABBY基因家族的主要扩增方式为片段复制。圆齿野鸦椿YABBY基因家族的表达具有组织特异性,EkYABBY3、EkYABBY7和EkYABBY8分别在胚胎、雌蕊和雄蕊进行了高表达,EkYABBY9在花蕾和花瓣+萼片上进行了低表达,在其他组织进行了高表达。YABBY基因启动子2 000 bp处含有多个非生物胁迫响应和激素响应元件,如光响应元件、赤霉素响应元件。圆齿野鸦椿种子发芽率低且具有深休眠现象,研究发现INO类基因和YAB2类基因在其种子发育过程中发挥重要作用,本研究结果为进一步深入研究YABBY基因家族对圆齿野鸦椿种子发育的生物学功能提供科学依据。     

圆齿野鸦椿种子预处理和苗木生长规律及育苗技术研究

通过2年以上对圆齿野鸦椿的种子预处理、种子主要播种品质参数测定和对苗木的苗高、地径、主根长、大于5cmI级侧根数、根幅、冠幅、鲜叶重、鲜干枝重、鲜根重的测定,以及对苗木物候、苗木生长规律进行研究,从而得出圆齿野鸦椿的较为系统的育苗技术。     

梨果采收期与果实品质及耐贮性关系

‘鸭梨'、‘雪花梨'是河北省2个主栽梨树品种,生产上果实采收期多在9月中旬和9月上旬,果实发育期分别为160 ～ 170 d和140 ～ 145 d,果实的采收期与其品质及耐贮性关系密切.通过测定分期采收的‘鸭梨'、‘雪花梨,的果实发育天数、各种理化性状指标及其贮藏期的变化规律,推测其最佳的采收期.结果表明,在石家庄地区,‘鸭梨,、‘雪花梨'适宜长期贮藏的采收期为9月21-28日;短期贮藏或即时销售的果实可适当延后采收,推迟到10月上旬.     

Regeneration and structure of mixed conifer forests under single-tree harvest management in the western Bhutan Himalayas

We examined the regeneration and structure of mixed conifer forests under single-tree harvest management in western Bhutan. Sixteen 900 m² (30 m × 30 m) plots were sampled at four Forest Management Units (FMUs; Chamgang, Gidakom, Paro-Zonglela, and Haa-East) representing the forest type, including half the plots in single-tree harvest stands and half in unlogged stands. In addition, we solicited information on traditional forest management practices from informants using survey questionnaires and collected tree species data from felling records from respective local forest offices. Rural timber demand is concentrated on the removal of straight and well-formed bluepine trees for beams, planks, and scaffolding. Single-tree harvest, however, has not significantly altered stand structures from unlogged stands. Similarly, tree regeneration is not different when comparing single-tree harvest and unlogged stands, except at Chamgang FMU, where seedling densities were generally higher in harvested stands than in unlogged stands. These results indicate that single-tree harvest is not detrimental to regeneration and utilization of mixed conifer forests in western Bhutan.     

The influence of timber harvest on the structure and composition of riparian forests in the Coastal Redwood region

The composition and structure of riparian forests in the coast redwood region were analyzed in relation to the length of time since timber harvest, and the width of riparian buffer zone. Ten sites were sampled in the central range of the coast redwood forest type within a variety of post-harvest age groups and riparian buffer zone widths. Data was collected using randomly selected sample plots adjacent to perennial coastal steams. Correlation Fisher's r to z tests and two-tailed t-test were used to examine the relationship between the sample variables and the experimental parameters “years since harvest”, and “width of buffer.” Results indicate that canopy cover was negatively correlated to “years since harvest” with the highest level of canopy cover found on the youngest sites and the lowest level found on the old-growth sites. The hardwood to conifer dominance ratio and the basal area of Alnus rubra (red alder) were correlated negatively to both “years since harvest” and “buffer width” indicating that timber harvest favored hardwood species. Late seral associates such as Oxalis oregana (redwood sorrel), Anthyrium filix-femina (lady fern), and Vaccinium parviflorum (billberry) were found preferentially in older forests and sites with wider buffer zones, while non-native species such as Hedera helix (English ivy), Pampas cortedaria (pampas grass), and Myosotis latifolia (forget-me-not) were found preferentially in younger forests and areas with smaller buffer zones.     

Economic feasibility of and vegetation responses to biomass harvest in managed loblolly pine plantations

We evaluated two biomass harvest methods, (1) Whole Tree Thinning (WTT; third-row thinning), and (2) Whole Tree Thinning with Fuelchips (WTTF; third-row thinning plus remove all accessible hardwood stems >2.5 cm diameter at breast height and understory shrubs in thinned area of stand) in a 21-year-old loblolly pine (Pinus taeda L.) plantation in northwest Florida for their harvesting yields and productivities, costs, and effects on groundcover. Both WTT and WTTF produced similar quantities of roundwood (~70 Mg ha^?1) and chips (8.43–13.12 Mg ha^?1) without significantly added operational time (15.77–28.12 Mg h^?1). On-board costs of chip production (US$6.93 to 10.60 Mg^?1) and total cost of roundwood and chip production (~22.5 US$ Mg^?1) of the two harvest methods also did not differ significantly. Following either WTT or WTTF, overall percent groundcover recovered within 6 months. While shrub and grass cover were similar, forb cover in WTT increased significantly following six months of harvests. Importantly, the study suggests that biomass removal is an attractive option that could be integrated with traditional silvicultural thinning methods to manage vegetation and alleviate hazardous fuel and wildfire conditions, leading to improved forest health.     

Fodder production of some shrubs and trees under two harvest intervals in subhumid southern Ghana

The study was undertaken to determine the relative performance of 13 fodder trees and shrubs in herbage production and quality under two forage regrowth periods six and 12 weeks. In primary growth assessment it was found that the species which achieved the most height growth were Cajanus cajan, Sesbania sesban and Gliricidia sepium. In terms of herbage dry matter production the species which performed best were Cajanus cajan, Flemingia macrophylla, Calliandra calothrysus, Codariocalyx gyroidesand Gliricidia sepium. In crude protein content the superior species were Albizia lebbeck, Cajanus cajan, Leucaena leucocephala and Sesbania sesban. Regrowth harvests in the second year showed Gliricidia sepium, Calliandra calothrysus and Flemingia macrophylla achieve the greatest herbage yields with yields in excess of 1 t/ha obtaining at the first 12 week regrowth harvest. Albizia lebbeck, Cajanus cajan, Leucaena leucocephala and Samanean saman produced consistently very high crude protein levels (more than 20%) in the regrowth harvests. Calcium contents of herbage of all test species in the regrowth harvests were in excess of the critical minimum requirement of 0.44% for ruminant feeding. This revised version was published online in June 2006 with corrections to the Cover Date.     

Timber harvest,damage to crop plants and yield reduction in two Costa Rican coffee plantations with Cordia alliodora shade trees

Both model and field estimations were made of the damage inflicted to coffee plants due to the harvest of timber shade trees (Cordia alliodora) in coffee plantations. Economic analyses were made for different coffee planting densities, yields, and both coffee and timber prices.Damage due to tree felling and log skidding should not be a major limitation to the use of timber shade trees in coffee plantations. The timber price that would balance all discounted losses and benefits to zero, for scenarios with and without trees ranged between 8–20 US $/m³ (current overbark log volume at the saw mill yard is US$ 66/m³). There will be lower margins for coffee damage in high yielding plantations, specially in years of good coffee prices. Nevertheless, the use of timber shade trees is recommended even in these scenarios.     

Effects of bark harvest and other human activity on populations of the African cherry (Prunus africana) on Mount Oku, Cameroon

Bark extracts from the African cherry, Prunus africana (Rosaceae), are a popular treatment for enlarged prostates. Harvests of the bark began in Cameroon in the 1970s. Because of concerns regarding the sustainability of the trade, the species is included on the IUCN Red List and in CITES Appendix II. This study followed five P. africana populations in the Kilum-Ijim Forest Preserve on Mount Oku, Cameroon, examining growth, mortality and reproductive parameters, as well as response to harvest and other human activities. During the first part of the study (1998–1999), the forest had limited human activity; by the second part (2007–2008), more activity was apparent, including wildfires, grazing and a forest-wide bark harvest in 2005/2006. Over the study period, population structure differed from a typical J-shaped frequency curve for long-lived species, which may reflect past harvesting. After the 2005/2006 harvest, the population structure had shifted slightly toward the smaller size classes. In addition, the number of surviving trees was reduced in all size classes. About half of the reproductive trees died during the study. Size class was not a significant predictor of death, but the location of the harvest (plot) was. All trees affected by wildfires died, suggesting that the species is not adapted to fire. Trees that were harvested without disrupting the vascular cambium survived better and had minimal loss of crown. Thus, the fate of the trees in a given plot may lie in the care taken by an individual harvester. Average growth (0.34 cm per year) was not significantly different among the size classes. Crown die-back significantly reduced fruit production, obscuring the asynchronous alternating fruiting pattern. Seedling numbers followed a similar alternating pattern, but survival was negligible due to grazing. The combined factors of mortalities of a large percentage of reproductive trees (especially the largest ones), highly reduced fruit production and poor seedling survival offer a bleak prognosis for future regeneration and long-term persistence of the species in this forest. Only after decades of harvest are existing standing crop inventories and scientifically based annual quotas now being determined. It is known that the trees are easily domesticated. Efforts have been intensified to train villagers and community forest managers in vegetative propagation techniques and nursery practices, offering some hope that the species can be successfully managed to provide for sustainable harvests and dependable rural livelihoods.     

Anthropogenic Influences on Wild Nutmeg Fruit Crop in the Western Ghats of India

Myristica dactyloides is characteristic of the mid- and high-elevation evergreen forests of the Western Ghats of India. Aril and seeds of the species are valuable nontimber forest products and are harvested extensively. We made visual estimates of fruit crop size in nine populations. We assessed disturbance using five variables: distance from road, method of harvesting fruits, nonforest matrix around the population, seedling regeneration, and protected area status. Unsustainable harvest and proximity to road impacted fruit crop, as did the nonforest matrix (F = 38.17 df = 5,102, p < .001). While high protection and measures against harvesting keep some populations safe, the harvest method plays a crucial role in determining total fruit production and seedling recruitment in the species.