共查询到19条相似文献,搜索用时 140 毫秒
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【目的】研究重庆金佛山3种喀斯特森林群落(常绿落叶阔叶混交林、落叶阔叶林和常绿阔叶林)木本植物种子雨和土壤种子库的组成、动态、空间分布格局及幼苗萌发情况,揭示喀斯特森林的更新潜力与发展方向,为喀斯特森林管理提供理论依据。【方法】在每种林型中随机设置9个种子雨收集器,从种子下落初始到结束,每15天收集1次,共收集8次。同时在每种林型中随机挖取6个土壤种子库样方,分枯落物层、0~2 cm土层和2~5 cm土层取样,对种子雨、种子库所收种子进行分类鉴别,并分别统计完整、虫蛀、残缺和霉腐4类种子的数量,应用氯化三苯四氮唑(TTC)染色法对所有完整种子进行活性鉴定。采用样方法调查幼苗种类和数量。【结果】3种林型种子雨的下落时间和高峰期时间基本一致;常绿阔叶林种子雨强度最大(1 453颗·m-2),其次为落叶阔叶林(486.11颗·m-2),常绿落叶阔叶混交林(152.22颗·m-2)最低,林型间种子雨强度差异显著(P<0.05); 3种林型种子雨中活性种子占比(活性种子数量占完整种子数量的比例)差异显著(P<0.05)... 相似文献
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环境因素对风箱果种子萌发的影响 总被引:1,自引:0,他引:1
以风箱果自然成熟的种子为研究对象,对影响种子萌发的环境因素进行了研究.结果表明:种子属于需光性种子,光照能够促进种子萌发.在10~25℃条件下,种子均能萌发,以20℃发芽率最高[(78.33±1.67)%],萌发速度最快[(23.61±2.29)%];播种深度显著影响种子的出苗率(P<0.01),不覆土(O cm)出苗率高达(68.33±6.01)%;超过0.5 cm,出苗率显著降低,2 cm时出苗率为O;种子在土壤中萌发时,土壤的适宜含水量为40%,此时出苗最快[(15.44±0.15)%],出苗率最高[(51.67±1.67)%],幼苗的死亡率也较低[(16.67±8.82)%].自然条件下,温度不是种子萌发的限制因子,影响风箱果种子萌发和幼苗成功定居的关键因子是土壤含水量、光照以及播种深度. 相似文献
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经测定,俄罗斯大果沙棘丘依斯克(Hippophae rhamnoides)种子的千粒重为17.75 g,与其它沙棘属的种子相比,其千粒重较大,为其2倍左右。在水、气适宜的条件下,主要研究了温度分别为15℃、20℃、25℃、30℃和光照强度分别为25%、50%、75%、100%状态下的不同处理对丘依斯克种子萌发的影响,并根据胚根生长量和全株生物量对沙棘种子发芽效果进行了评价,提出了沙棘种子发芽的最适温度和光强。结果表明,在25℃条件下,种子萌发最早,发芽势高达33.0±4.76%,发芽率高达95.5±1.5%,且主根生长量和生物量最大,分别为4.5±0.09 cm和0.137±0.002 g;75%光强最适合沙棘种子萌发,种子萌发最早,发芽势高达61.5±1.7%,发芽率高达86.0±1.1%,且主根生长量和生物量最大,分别为3.7±0.2 cm和0.108±0.004 g。因此,在直播营造大果沙棘防护林时,建议首选25℃的温度条件,同时,建议进行适度遮荫处理,在获得优质苗木的同时,降低蒸发量。 相似文献
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降香黄檀播种及幼苗生长规律研究 总被引:2,自引:1,他引:1
《福建林业科技》2015,(1)
采用室内和田间试验,研究不同植物生长调节剂(IBA、GA3、6-BA,以清水为对照)、种子不同处理方式(处理A:将种子用清水浸泡48 h后,直接播于苗床中;处理B:在处理A的基础上覆盖一层塑料薄膜;处理C:将种子进行层积催芽露白后,直接播种于苗床中)对降香黄檀种子萌发、出苗及苗木生长的影响。室内种子萌发试验结果表明,植物生长调节剂处理可显著提高降香黄檀种子的发芽率和发芽势,大小顺序均表现为IBAGA36-BACK。大田播种育苗试验表明,经催芽后播种(处理C)和苗床覆盖薄膜(处理B)的出苗率均达到70%以上,显著高于露地直接播种(处理A);降香黄檀1年生幼苗的高生长和地径生长均呈"S"形曲线。 相似文献
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以粘土和花生粉为主原料制作人工种子,添加不同含量的蚕沙(5%、10%、20%、40%,分别记为SE5、SE10、SE20、SE40)模拟不同程度被昆虫取食损坏的种子,研究啮齿动物对昆虫取食损坏种子的取食和搬运行为策略。结果表明:1种子投放2 d后,纯粘土(NC)种子的留存率最高(92.9%),其次为蚕沙含量较低(SE5)的种子(47.1%),不含蚕沙种子(SE0)的留存率最低(36.1%);种子投放4 d后,NC种子和SE40种子留存率仍分别高达76.4%和60.8%;NC种子在投放10 d和17 d后仍分别有6.8%和5.6%留存,但其他类型种子留存率均为0。2NC种子被啮齿动物的就地取食率最高(63.2%),SE40种子次之(59.2%),且随种子蚕沙含量的减少呈波动性降低趋势;种子被搬运后的取食率以SE20种子最高(45.0%),SE0种子略低(33.7%),NC种子仅有4.1%;SE0和SE5种子被动物搬运后的贮藏率分别高达34.1%和22.9%,NC、SE20和SE40种子均低于1.5%;3SE0种子被动物搬运后取食和贮藏的平均距离最大(5.9 m),且随蚕沙含量的增大而逐渐减小,NC种子被动物搬运后取食和贮藏的距离均最小(分别为1.2 m和0.1 m)。 相似文献
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用10~1000 mg/L稀土溶液对马占相思和大叶相思浸种24 h后的试验结果表明:适宜浓度的稀土溶液可促进马占相思和大叶相思种子内含物的转化,从而促进种子的萌发和幼苗生长,但同一稀土溶液对不同树种的适宜浸种浓度不同。马占相思以10 mg/L处理有利于提高种子发芽势并缩短发芽时间;大叶相思10~30 mg/L处理显著提高种子发芽率和发芽势,但没有显著缩短发芽时间。200 mg/L及以上浓度浸种对2种树种种子萌发有抑制作用。考虑指标多重比较差异及经济因素,10 mg/L处理较利于马占相思和大叶相思幼苗高和根系生长。 相似文献
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The white-winged guan (Penelope albipennis, Cracidae), thought extinct until 1979, today numbers <300 individuals. We investigated the role of the guans in seed dispersal and predation dynamics by recording seed germination from fecal samples of wild birds during the dry-season (May–December 2010). This study was conducted at Chaparri Ecological Preserve, in the critically endangered Tumbesian ecosystem on the western slope of the Andes. Field observations show that this bird is a frugivore; Cordia lutea (Boraginaceae) was the primary fruit consumed of the eight species of seeds collected from droppings. Collected seeds were sown in pots under nursery conditions and monitored for germination. Germination rates of passed seeds for Cordia lutea were compared to those that had been collected from a control group of trees. Germination was significantly different between fecal and control seeds, suggesting the plant germinated better after passing through the guans alimentary tract. The identification of flower structures, and digested seeds in feces show that guans can be effective fruit and flower predators. This study provides further information regarding the diet for conservation of the white-winged guan and suggests the bird may aid seed germination in some instances and may act as a predator in others. 相似文献
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To date, the evolutionary significance of mast seeding is still poorly understood. It is also not clear whether and how seed production and clonal growth interact and then influence the colonization and recruitment of plant species that seeds are dispersed by animals. We released seeds of Corylus mandshurica in seed-rich and seed-poor years (2008–2012), to test the effects of mast seeding and clonal growth on regeneration of this clonal shrub. Our study showed that seed caching of C. mandshurica was higher in seed-rich years than that in seed-poor years. However, mast seeding failed to result in seedling establishment of C. mandshurica. Despite a negative effect of mast seeding, vegetative reproduction was common in the seven consecutive years (2007–2013), suggesting that clonal reproduction plays an important role in population spreading of C. mandshurica. Seeds are unlikely to produce seedlings in both seed-rich and poor years, suggesting that sexual reproduction contributes little to the regeneration of C. mandshurica but may be responsible for initial establishment via episodic seed dispersal. 相似文献
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香果树种子休眠和萌发的生理特性 总被引:11,自引:0,他引:11
为了解决香果树Emmenopterys henryi种子萌发困难的问题,使用不同的光照条件较系统地研究了香果树种子休眠和萌发的生理特性.结果表明:香果树种子属典型的光敏感性种子,在黑暗中无论恒温或变温条件下均完全不能萌发;整个萌发过程需1 000 lx光照强度和每天照光16 h;在光照条件下适宜的萌发温度为20℃、25℃恒温,其次是30℃恒温和30℃(日)、20℃(夜)变温. 相似文献
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对湖北省建始县长岭岗林场日本落叶松种子园内花粉散发和空间分布特征进行2年的研究.结果表明:日本落叶松花粉散发受气候因子的影响很大;整个散粉期间日本落叶松花粉散发量呈现低-高-低的节律,每天花粉散发量呈极显著差异;散粉期间出现一个散粉高峰期,一般持续3~5 d,散粉高峰期间每天不同时间段的散粉量也呈现低-高-低的节律,散粉高峰时间段出现在8∶00~16:00,具体时间段受当日天气的影响,每天不同时间段内花粉散发量呈极显著差异;种子园内不同样点花粉散发量中,八方位花粉散发量及树冠内、中、外部花粉散发量均未达到显著性差异,花粉分布都呈均匀分布型;种子园内不同垂直高度花粉散发量呈极显著差异,花粉分布呈集群分布型. 相似文献
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Abelardo Aparicio Rafael G. Albaladejo Miguel Á. Olalla-Tárraga Laura F. Carrillo Miguel Á. Rodríguez 《Forest Ecology and Management》2008
While maximizing plant species richness continues to be central in the design, conservation and reforestation action plans, plant life histories are receiving increasing attention in assessments for the conservation of biodiversity in fragmented landscapes. We investigated the determinants of woody plant species (trees, shrubs and climbers) richness in the forest patches of the Guadalquivir river valley, a Mediterranean agricultural landscape with ∼1% forest cover. We analyzed three species richness variables, total, and those corresponding to species with short-distance (ballistic, barochorous, myrmecochorous and short-distance anemochorous) and long-distance (anemochorous, endozochorous, exozoochorous, hydrochorous and dyszoochorous) dispersal systems, which significantly characterize earlier and late successional stages, respectively. We selected eleven predictor variables related to habitat structure (patch area, shape, distances to the nearest patch and reserve, and general isolation), physical environment (temperature, precipitation, elevation, and lithological heterogeneity), and anthropogenic influences (disturbance and proportion of old-growth forest). We used ordinary-least-squares multiple regression (OLS) and the Akaike's information criterion (corrected for spatial autocorrelation) and derived indices to generate parsimonious models including multiple predictors. These analyses indicated that plant species richness increase primarily along with increasing patch area and decreasing disturbance, but also detected secondary effects of other factors when dispersal was considered. While the number of species with potential long-distance dispersal tended to increase in more isolated patches of areas with greater precipitation and lithological heterogeneity (e.g. highlands at the valley edges), the number of species with short-distance dispersal increased towards drier and less lithologically complex zones with shorter between-patch distances (e.g. central lowlands). Beyond emphasizing the need to consider dispersal in fragmentation studies, our results show that woody plant species richness would be favoured by actions that increase patch area and reduce anthropogenic disturbances particularly in lowland forests. 相似文献