湖南常绿阔叶林群落物种多样性初步研究

湖南常绿阔叶林物种多样性Ｓｉｍｐｓｏｎ指数为２８－４０，ｓｈａｎｎｏｎ－ｗｉｅｎｅｒ指数为４，均匀度为０．７。其经纬度变化没有一定的规律性，下层乔木对群落物种多样起有很大的作用，人类的干扰对其影响相当大。     

短轮伐期菇木林人工培育技术研究

选用银荆、南酸枣、杜英、马褂木等２２个速生阔叶树种为试材。在庆元不同立地地段进行不同树种、不同种植密度和不同树种混交方式造林试验,通过连续５年的调查、测试表明,银荆、南酸枣、杜英、马褂木等树种具有早期丰产的特性,采用密植造林４-５年可获得较高的生物产量与经济效益,同时提出了“短轮伐期人工菇木林丰产栽培”模式。     

短轮伐期菇木林栽培试验研究

马褂木具有较强的竞争能力 ,生态适应性强 ,生长快 ,成材早 ,在早期就可表现出速生丰产性能 ,是最佳的短轮伐期菇木树种 ;马褂木既可营造纯林 ,也可营造混交林 ,保存率高达 90 %～ 96 %,明显优于其它伴生树种。杜英、枫香也是适宜的菇木树种 ,杜英生长速度较快 ,与马褂木、厚朴分别混交 ,生长效果都较好。枫香与马褂木混交 ,种间关系协调 ,树种生物学特性互补 ,林分空间结构分布合理 ,是一种成功的混交模式。酸枣生长快 ,适应能力强 ,保持率较高 ,但侧枝多 ,冠幅庞大 ,适合营造混交林 ,且混交比例不宜太大 ;与马褂木混交 ,种间关系协调 ,相互促进生长。厚朴的生长潜力还没有充分发挥 ,需进一步观察。乐昌含笑、白玉兰初期生长缓慢 ,暂不适用作菇木树种。     

短轮伐期菇木林营造技术研究

银荆、南酸枣、秃瓣杜英、马褂木等8个袋栽香菇试验表明，麻栎、南酸枣每千克干料产鲜香菇为944g和882g，比对照高45．23％和35．69％；桤木、秃辨杜英、银荆、锥栗、马褂木、枫香等产菇量比对照高7．18％～20．92％。造林试验表明，4a生的银荆树高8．93m，胸径8．20cm，生物产量高达189891kg／hm^2；5a生南酸枣、秃辨杜英、马褂木、枫香、锥栗、麻栎生物产量达83790～150228kg／hm^2。研究认为银荆、南酸枣、秃辨社英、马褂木等树种具有早期丰产的特性，采用密植造林4～5a可获得较高的生物产量与经济效益。     

海南霸王岭陆均松类热带山地雨林伐后林结构与物种多样性研究

霸王岭林区是海南岛最典型的热带山地雨林分布区.在该区,现存分布面积最广、资源数量最大的是热带山地雨林的各种伐后林.以霸王岭分布最广的以陆均松(Dacridium pierrii)为主的山地雨林的伐后林为对象,研究了其组成、径级、高度结构和物种多样性特征,对比分析了伐后林与原始林以及伐后林不同类型之间的异同.结果表明:原始热带山地雨林经采伐后中小乔木和灌木的优势度增大,而大乔木树种的优势度则明显下降.阳性树种的种类、数量和相对重要性随采伐破坏的程度而增加.伐后林中矮、小树木在林分中比例随采伐破坏的程度增加,而高、大树木,特别是进入主林层树木的比例则随采伐破坏的程度明显下降.从林分测树因子的变化来看,采育择伐和径级择伐的林分要优于大强度择伐和皆伐的林分.原始林的物种丰富度大于伐后林,但其多样性指数和均匀度指数大都小于伐后林.组成上与原始林相似性较大的伐后林是各种择伐后的林分,而皆伐后的林分与原始林在组成上已有很大差别.     

不同恢复时期红松阔叶林群落结构与多样性特征

以长白山不同恢复时期红松阔叶林群落为研究对象,采用空间序列代替时间序列的方法,探讨了不同恢复时期(恢复20年、30年、70年和原始林)红松阔叶林群落的结构与多样性特征.结果表明:恢复70年的群落中乔木科、属、种特征与原始林相同,而恢复20年和30年的群落则与原始林存在显著差异,物种多度分布曲线也显示了相同的特征.恢复70年的群落与原始林中的物种丰富度及多度随径级和高度级的分布形式相同,但恢复20年和30年的群落则与原始林不同,并且缺少大径级和较高的树木.恢复30年的群落中乔木和灌木的物种丰富度最高,而恢复70年的群落则与原始林无显著差异,草本物种丰富度在原始林中最高.乔木Shannon-Wiener多样性指数也表现出与物种丰富度相同的大小关系,而灌木在4个不同恢复时期群落中无显著差异,草本则是恢复30年和原始林较高.恢复70年的群落与原始林相似性最高,而恢复20年的群落与原始林相似性最低.从群落的结构与多样性特征来看,恢复70年的群落结构与多样性特征已经接近原始林群落水平.     

沈阳东陵区油松栎林群落特征及物种多样性研究

以沈阳市东陵区油松栎林群落为对象,分析了群落特征,结果表明,油松栎林群落共有种子植物161种,分属49科121属,区系组成丰富。在植物区系地理成分上,种的分布类型以温带性质居多,共143种,占总种数的88.82%,表明了群落植物区系组成的温带亲缘关系;在群落结构上,油松栎林群落以地面芽植物最多,占36.0%;群落可分为乔木层、灌木层和草本层3个层次;种间联结性以山里红与黄波罗呈显著正关联外,其他种间联结性都较低。群落木本植物科-属-种组成多样性大小顺序为属-种多样性>科-属多样性>科-种多样性。     

不同林龄杉木林群落结构与物种多样性研究

为促进人工杉木林更好的养护和发展,本文对湖南芦头森林生态站不同林龄杉木人工林的群落结构和物种多样性进行了研究。结果表明:幼龄林物种分布分散,物种丰富度较高;中龄林分布密集,物种丰富度较低;14年生杉木林的Shannon-Wiener多样性指数和Simpson多样性指数最高,分别为2.209和0.875;6年生杉木林的Pielou均匀度指数最高,为1.487;物种多样性随林龄的增大而下降,随树高的增大而下降;同龄杉木林中,树高结构具有中间树高级分布的林木株数最多的规律。研究结果有助于理解物种组成、群落结构、多样性在演替过程中的变化规律,为维持人工杉木林健康的生长和生态系统服务功能提升提供了科学依据。     

迭山北坡云冷杉林火烧迹地灌木群落特征和物种多样性研究

为探究云冷杉林火烧迹地群落恢复与重建及其稳定性维持机制,以青藏高原东北边缘迭山北坡云冷杉林火烧迹地恢复15 a灌木群落为研究对象,针对不同坡位处典型群落,分析群落组成与结构特征和α物种多样性.结果显示:在坡位梯度上,从上到下可依次划分唐古特忍冬+扁刺蔷薇-密生薹草群落、箭竹-密生薹草群落和黑水柳-野草莓群落3种典型群落...     

短轮伐期与截杆促萌结合营造菇耳林技术探讨

菇耳业的迅速发展导致阔叶树资源日益缺少以及需求量的不断增加,制约了菇耳产业的稳定发展.以短轮伐期与截杆萌条培育技术营造菇耳林,采取高度集约经营的方式,可加快发展菇木林资源,缩短生产周期,提高单位面积产量,增加经济效益,使资源得到合理的开发利用,从而为菇耳产业可持续性续发展创造良好的生态环境和提供充足的基质资源     

Bottomland hardwood forest recovery following tornado disturbance and salvage logging

Catastrophic wind events, including tornado, hurricane, and linear winds, are significant disturbances in temperate forested wetlands. Information is lacking on how post-disturbance salvage logging may impact short and long-term objectives in conservation areas where natural stands are typically managed passively. Woody regeneration and herbaceous cover were assessed for three years in a bottomland hardwood forest across a gradient of damage from an F4 tornado, with and without subsequent salvage logging. Soil disturbance intensity and recovery associated with salvage logging within wind-disturbed sites were also assessed. Woody stem density and proportion of potential overstory species (species with the potential to occupy a position in the canopy) increased as a function of wind disturbance intensity. Stem density, proportion of overstory trees, or species diversity did not differ between wind + salvage and wind-disturbed-only plots. Significant dissimilarity occurred among soil disturbance classes within salvaged sites. By the third growing season, vegetation in soil disturbance classes in wind + salvage areas was converging toward undisturbed conditions and bottomland hardwood forest recovery was underway in all vegetation disturbance types and soil disturbance classes. Post-tornado salvage logging, applied judiciously, may contribute to microsite and vegetation diversity.     

杉木、檫树混交林生物量及林地土壤肥力研究

通过对杉木檫树混交林与杉木纯林和檫树纯林的造林实验,在同一阳坡上三个实验区中设立600m^2标准地,分别对纯林、混交林的生物量和林地土壤性状进行测定,对标准地上标准木用全重法分别树干、枝、叶和根进行乔木层生物量测定,对土壤按常规方法测定其物理性质和化学性质。研究结果表明：混交林的生物量大于纯林,对林地土壤的物理和化学性质的影响效果优于杉木纯林而劣于檫树纯林。     

Bird abundance and diversity across a hardwood gradient within early seral plantation forest

The extensive removal of competing broadleaved shrubs in forest plantations typically results in structural and compositional simplification of early seral habitat. However, information on the tradeoffs between such intensive forestry practices and biodiversity is scant. Here we assess the magnitude and direction of potential impacts of intensive forest management on populations of early seral-associated breeding birds. Observed population declines of several Neotropical migrant bird species are hypothesized to be linked to the loss of early seral habitat on the breeding grounds. We investigated the association between broadleaved hardwood cover and avian abundance and diversity in intensively managed early seral Douglas-fir (Pseudotsuga menziesii) stands of the Pacific Northwest. Bird species richness decreased across an elevational gradient, but did not vary as a function of either local vegetation composition or structure. In contrast, bird abundance was strongly associated with hardwood cover at local and landscape scales, especially for foliage-gleaning species. We found strong support for the existence of a threshold in relative bird abundance as a function of hardwood at the stand scale; abundance doubled with an increase from 1% to ∼6% hardwood and then reached a plateau. Though abundance of leaf-gleaners increased even more strongly across a gradient in hardwood cover, evidence for a distinct threshold was less clear. We conclude that when early seral hardwood forest is scarce, even small increases in hardwood may provide substantial conservation benefits. However, for some species (i.e., foliage gleaners), there may be more direct trade-offs in abundance and juvenile recruitment with hardwood management intensity.     

油橄榄低效林土壤培肥技术研究

【目的】为给油橄榄的科学施肥提供参考依据。【方法】以油橄榄品种阿贝基娜为试材,通过对低效园与高产园土壤养分的调查、油橄榄叶片中各营养元素的检测,找出了影响油橄榄生长发育的关键营养元素;再选择生长势弱且挂果较少的样树,对其施用有机肥加浓度分别为0.3%、0.4%、0.5%和0.6%的高效水溶肥进行施肥试验,以常规施肥处理为对照,比较分析了不同施肥处理对油橄榄树势、叶片和果实生长发育的影响情况。【结果】养分调查中,低效园与高产园的效益差别受到土壤营养状况的影响,高产园区油橄榄叶片中N、P、K、Ca、Zn、Fe的含量均高于低效园的;其中,N含量未达到国外标准,P、K含量符合国外标准,而Ca、Zn、Fe含量均高于国外标准。施肥试验中,与常规施肥处理相比,施用有机肥加浓度分别为0.3%、0.5%、0.6%的高效水溶肥,均促进了油橄榄的树高生长;施用有机肥加浓度分别为0.4%、0.5%、0.6%的高效水溶肥,均能增加油橄榄叶片长度和百叶质量;施用有机肥加浓度分别为0.3%、0.4%、0.5%和0.6%的高效水溶肥,均能显著提高油橄榄坐果率,总体效果随水溶肥浓度的增加而呈先增后减的变化趋势,其中,施...     

株洲市芦淞区林地土壤肥力调查

通过对株洲市芦淞区林业用地土壤肥力因子和立地因子的调查,基本掌握了辖区内林地土壤分布、土壤肥力状况以及立地条件.为发展现代林业,转变林业发展方式,提高林业经济效益奠定了良好的基础.     

Nitrogen transformations and soil processes in a wastewater-irrigated,mature Appalachian hardwood forest

Wastewater bioremediation has been practised successfully in several forests without significant adverse effect on water quality of adjacent aquatic systems. However, long-term success of wastewater irrigation systems depends on an overall positive response of the forest ecosystem to substantial amounts of added water and nutrients over time. Municipal wastewater irrigation effects on the fate of added nitrogen in a mature Appalachian hardwood forest were investigated during the first 2 years of irrigation. Wastewater was secondarily treated, chlorinated, and sprayed on the study site at five rates. Forest litter N decreased on irrigated sites due to increased litter decomposition rates. Nitrogen mineralization potential (N₀) decreased greatly in soils irrigated at a rate of 140 cm year⁻¹ for 2 years. Net nitrification and relative nitrification (the amount of NO₃⁻-N as a proportion of the total mineral N) increased proportionally with irrigation rate. The highest irrigation rates increased denitrification activity and contributed significantly to the bioremediation process by removing nitrate that otherwise would have been subject to leaching. The increase in NO₃⁻ production in the soil and limited N sequestration by the forest system nevertheless resulted in a net loss of N via leaching. Nitrate concentrations of soil water increased owing to irrigation, with the highest rate at 11 mg 1⁻¹ on sites receiving 70 cm year⁻¹. During the 2-year period, the forest ecosystem experienced a net leaching loss of N that ranged from 14.8 to 105 kg N ha⁻¹ year⁻¹, depending on the application rate. It is likely that this mature hardwood forest will continue to lose N, and that little or no additional N will be sequestered.     

福建柏檫木混交林土壤肥力的研究

通过对福建柏檫木混交林与福建柏纯林的土壤酶活性、凋落物及土壤养分、土壤孔隙组成、土壤团粒组成等对比分析，认为福建柏檫木混交林具有较好的培肥能力，能降低多代经营造成的地力衰退，同时可以改善生态环境，是值得推广的针阔混交造林模式。     

辽西地区不同人工林地土壤肥力变化研究

为研究辽西地区人工林对石灰性褐土土壤质量的定向改良作用,以油松×沙棘混交林、山杏纯林、油松纯林3种人工林地为研究对象,对在石灰性褐土上的人工林土壤肥力进行了分析。结果表明,油松沙棘混交林能够显著提高有机碳含量,比荒地高42.8%;油松沙棘混交林、油松纯林土壤碱解氮分别比荒地增加34.6%和33.6%,人工林对土壤全氮含量影响不显著;油松沙棘混交林的土壤速效磷和水溶性磷分别比荒地提高14.9%和128.57%;人工林增加了土壤速效钾含量;林木的改良土壤作用主要表现在土壤表层。