土壤厚度对麻疯树生殖与生长性状的影响

地形因素对景观格局的塑造受到关注,而土壤资源性因素对生活史性状的影响很少受到重视。本文首次研究了干热河谷麻疯树生长与生殖性状对土壤厚度的反应。结果如下:(1)土壤厚度对雌花数量、性比都存在明显影响,土壤厚度较大时,雌性适合度较高;(2)土壤厚度明显影响到营养性构件大小,土壤资源丰富样地营养性构件明显较大,分支能力较强;(3)土壤厚度较大时,果期构件的果实包装良好,生殖频率、果实数量、千粒重都明显大于土壤厚度较薄样地,而结籽率、败育率变化不明显;(4)土壤厚度较大时,个体高度较大,垂直空间资源利用相对充分,而冠幅和地径则容易受到密度效应制约;(5)土壤厚度较大时,果实及其组分性状都较大,种子产量潜力较大。结论表明:土壤环境资源充沛时,麻疯树雌性适合度明显,这种生殖潜力还与营养性构件和个体生长优势(或者构型)紧密相关;土壤环境资源对生殖潜力的调节是通过提高构型参数来实现的。本文对于认识土壤环境资源对基于种群的景观格局异质性和生活史性状型具有重要作用。在栽培和经营中需要重视深植与土壤调控。     

攀枝花干热河谷区麻疯树土壤微生物种群数量分析

本文利用土壤微生物传统数量测定法,分析了攀枝花9个麻疯树主要分布区土壤微生物数量分布情况。分析结果表明,在三大微生物种群中,细菌占93.9%,丝状真菌和放线菌分别占3.1%和3.0%;不同林分年龄土壤微生物总数差异显著,成熟林分(1 237.6×104)>人工幼林(955.4×104);土壤类型不同,微生物种群数量差异明显,红壤(1 349.2×104)>黄沙壤(1 306.8×104)>山地黄壤(580.0×104)。通过土壤主要微生物生理类群分析结果,攀枝花麻疯树主要分布区土壤微生物生理类群数量比较贫乏,在氨化细菌数量中,红壤(37.0×103)>黄沙壤(0.8×103)>山地黄壤(0.3×103);在好气性纤维菌中,红壤(0.8×103)>黄沙壤(0.7×103)>山地黄壤(0.3×103);消化细菌,反消化细菌在山地黄壤和黄沙壤有少量分布;在3种土壤中均未分离到好气性固氮菌,说明攀枝花麻疯树主要分布区土壤不适宜好气性固氮菌生长繁殖。     

豫西黄土丘陵区人工种植牧草对土壤的影响

研究了黄河中游区牧草种植对土壤养分和物理性状的影响。种植牧草可显著提高土壤有机质、氮的含量,并可改善土壤容量、孔隙度等物理性状。土壤类型不同,种草效应差异明显,土壤养分、含水量等的提高等与牧草种植年数呈正相关。     

攀枝花市麻疯树生殖构件特征与雌雄花配置研究

生殖构件是研究单性花同株植物性别分化影响因素的基础。本文描述了攀枝花市几个麻疯树林分的生殖构件数量特征和雌雄花配置问题,分析了影响生殖构件的可能因素,为认识麻疯树生殖特性提供了基础资料。麻疯树生殖构件的枝条长度主要以0．3cm～15cm、直径以0．5cm～1．0cm之间的枝条为主体,该区段生殖构件分布的频度较高。同时,麻疯树的雌花数量、雄花数量和花总数的数量结构都可以看出,分布图为偏左分布,表明这些生殖参数以低数量为主体。在样地水平上,不同调查样地麻疯树生殖构件的大小明显不同,可能受到土壤厚度的影响。麻疯树枝条大小（体积）是花数量的决定性因素,表明了枝条营养对生殖构件影响的有效性。麻疯树雌雄花配置存在明显的线性相关,暗示了麻疯树雌花比例或性比可能存在一定程度的遗传稳定性。雌花比例或性比与雄花数量、花总数无关,表明了雌花比例或性比决定受到环境因素影响。总之,攀枝花市麻疯树生殖构件偏小,性比较低,可能受到林分密度和土壤厚度等因素的影响。     

云南省红河州部分地区麻疯树种子的化学成分分析比较

从云南省红河州10个麻疯树产地采集其种子,并测定其生物学性状和化学成分,对相关数据进行方差分析比较,结果表明:产地不同,麻疯树种子的生物学性质、化学成分含量、种子油的组成和含量都有一些差异。麻疯树种仁粗脂肪含量为52.38%~65.89%,粗蛋白质含量为13.79%~26.13%,灰分含量为3.97%~5.15%,粗纤维含量为3.05%~4.74%。对麻疯树种子油进行分离得到6~9种化学成分,经鉴定,其主要化学成分为不饱和脂肪酸,其中亚油酸占总量的14.13%~36.91%,油酸占总量的35.79%~51.12%。从实验结果看:2、3、4、8号样品的种子出仁率、含油率及不饱和脂肪酸含量都高,且产量也高,可作为优良的种源进行推广应用,其种子的产地也适宜作麻疯树生物柴油的开发基地。     

贵州省麻疯树资源调查研究

为了解贵州省麻疯树的资源状况,为规模化培育麻疯树油料能源林提供技术贮备,对贵州省麻疯树的分布区、资源量和粗脂肪含量开展了调查和分析研究。贵州麻疯树资源分布在南、北盘江和红水河流域盘的乡镇,呈零星分布,为农家品种;现有资源结实量差异较大,一般单株种子产量在2~4kg,盛期可达15kg;不同产地种子粗脂肪含量差异较大,单株间亦存在差异;脂肪酸含量以油酸和亚油酸为主(77.37%),饱和脂肪酸含量少。     

麻疯树灰霉病发生规律及其防治方法

通过使用化灰和康丰8号混配药剂喷洒麻疯树对麻疯树灰霉病进行防治试验,结果表明:按每升清水加化灰600~1000mg与康丰8号500~900mg均匀混合配制而成的药剂能有效控制麻疯树灰霉病的蔓延,以混配药剂C(每升清水加化灰可湿性粉剂1 000mg和康丰8号水乳剂900mg)防治效果最好,连续喷施3次对灰霉病的校正防效达94.2%;不同喷药次数间防治效果差异显著,随着喷药次数的增加,防治效果也明显增加;不同浓度间的防治效果无明显差异。进行麻疯树灰霉病防治时,可尽量选用化灰和康丰2种混配药剂的低浓度剂量,适当增加喷洒次数,可达到预期的防治效果。     

四川麻疯树种群数量特征和更新研究

本文初步研究了四川麻疯树种群的天然更新和数量特征.麻疯树野生种群的种子产量较低,每0.067公顷产量约在50 Kg-150 kg之间,发芽受温度而不受光照影响,一般发芽率在50%-70%.幼苗建成发生在树下或附近地带,种子生产、土壤种子库形成和幼苗建成是麻疯树更新的三个关键阶段.麻疯树种群的数量特征是由更新状况、各大小级转化率和形成时间的影响,总体看麻疯树种群为增长型.在林业生产实践上,野生麻疯树种群需要进行低产林改造,进行林分结构调整和土壤改良,形成高产林分,利于麻疯树野生资源的科学利用和人工资源的科学培育.     

化学试剂处理对麻疯树幼苗抗寒性影响

研究了3种化学试剂处理对麻疯树幼苗低温前后抗氧化酶活性及相关生理生化指标的影响。结果表明：在低温胁迫前对麻疯树幼苗分别喷施不同浓度的NaCl、SA和PP。溶液,POD和SOD活性及相对电导率均发生变化。低温胁迫前,喷施0．1mmol／LSA和0．1mmol／LPP。溶液的麻疯树幼苗叶片POD和SOD活性均高于对照,可溶性蛋白质含量亦高于对照;低温胁迫后,两处理相对电导率和MDA值上升幅度低于对照和其他处理,且落叶时间推迟。表明对麻疯树幼苗喷施0．1mmol／LSA和0．1mmol／LPP。溶液能减缓低温胁迫下细胞膜的损伤;试验还发现,喷施NaCl溶液后植株可溶性蛋白质含量升高,不同化学试剂处理效果存在较大差异,而喷施化学试剂的抗寒效果优于对照。     

麻疯树2年生人工林构筑型对修枝与土壤肥沃性的响应

本文首次采用固定枝级划分方法,试验研究了麻疯树构筑型对土壤肥沃性的响应,并探究了构型调控效果的资源反应。结果表明:1)土壤肥沃时麻疯树分枝率高、分枝角度小、枝长较长,构型为密集型;土壤瘠薄时麻疯树分枝率低、分枝角度大、枝长较短,构型为游击型;2)人为修枝也没有明显影响构型对土壤肥沃性的响应策略,但却显著增加了肥沃生境下构型的密集性(30→22°);3)人为修枝改变了贫瘠生境下一级枝长度、一级枝枝径与二级枝长度,具有壮枝作用,而对肥沃生境树体枝条大小影响不明显(二级枝枝径例外);4)据分析,同龄顶芽间距离为间隔子,分枝间夹角为分枝角度,分枝率是分枝强度,类似于克隆植物构型;5)构型枝级划分采用了固定枝序法确定,主干分枝为一级枝,一级枝分支为二级枝,增加了枝级的稳定性,与传统枝级划分方法相反;6)分析还发现,麻疯树构型对资源异质性的响应根源在于一级枝分枝角度,该参数塑造了游击性与密集性的构型特性。     

林分结构调整对云南松次生林生长和土壤性质的影响

[目的]探究云南松林结构调整对林木生长和土壤性状的影响,为云南松林保护和利用提供科学依据。[方法]按照森林抚育规程对林分进行结构调整,采用典型取样法对比分析林分结构调整前后土壤性质和林木生长状况的差异。[结果]云南松林结构调整后,(1)结构调整样地单株蓄积量比对照样地提高了近60%,树高和胸径提高幅度均在15%以上,林下天然更新植株数量是对照样地的3.1倍;(2)结构调整后林内植物种类增加,林下灌木层和草本层盖度分别提高了63.3%和22.7%,灌木层和草本层平均高度分别提高了24.7%和17.9%;(3)结构调整样地现存凋落物量显著下降,与对照相比下降了20.4%,土壤表层温度、有机质含量、基础呼吸和土壤微生物生物量显著提高,土壤其他性质参数变幅相对较小。[结论]林分结构调整可显著提高云南松生长量,有利于云南松较大径级林木的培育;促进了云南松林下更新和林下植被发育,有利于林分群落结构的形成;提高了土壤微生物数量和活性,加速了土壤有机质转化,研究揭示林分结构调整促进了云南松林土壤—植物系统正反馈作用。     

Evolution of soil microbial biomass in restoration process of Robinia pseudoacacia plantations in an eroded environment

Vegetation recovery is a key measure to improve ecosystems in the Loess Plateau in China. To understand the evolution of soil microorganisms in forest plantations in the hilly areas of the Loess Plateau, the soil microbial biomass, microbial respiration and physical and chemical properties of the soil of Robinia pseudoacacia plantations were studied. In this study, eight forest soils of different age classes were used to study the evolution of soil microbial biomass, while a farmland and a native forest community of Platycladus orientalis L. were chosen as controls. By measuring soil microbial biomass, metabolic quotient, and physical and chemical properties, it can be concluded that soil quality was improved steadily after planting. Soil microbial biomass of C, N and P (SMBC, SMBN and SMBP) increased significantly after 10 to 15 years of afforestation and vegetation recovery. A relatively stable state of soil microbial biomass was maintained in near-mature or mature plantations. There was an increase of soil microbial biomass appearing at the end of the mature stage. After 50 years of afforestation and vegetation recovery, compared with those in farmland, the soil microbial biomass of C, N and P increased by 213%, 201% and 83% respectively, but only accounting for 51%, 55% and 61% of the increase in P. orientalis forest. Microbial soil respiration was enhanced in the early stages, and then weakened in the later stage after restoration, which was different from the change of soil organic carbon. The metabolic quotient (qCO₂) was significantly higher in the soils of the P. orientalis forest than that in farmland at the early restoration stage and then decreased rapidly. After 25 years of afforestation and vegetation recovery, qCO₂ in soils of the R. pseudoacacia forest was lower than that in the farmland soil, and reached a minimum after 50 years, which was close to that of the P. orientalis forest. A significant relationship was found among soil microbial biomass, qCO₂ and physical and chemical properties and restoration duration. Therefore, we conclude that it is possible to artificially improve the ecological environment and soil quality in the hilly area of the Loess Plateau; a long time, even more than 100 years, is needed to reach the climax of the present natural forest. __________ Translated from Acta Ecologica Sinica, 2007, 27(3): 909–917 [译自: 生态学报]     

The genetic diversity of Jatropha Curcas (L.) germplasm in Ghana as revealed by random amplified polymorphic DNA (RAPD) primers

Jatropha curcas (L.) has gained popularity as a biodiesel plant to serve as an alternative fuel source and generate income to small landholders. The success of J. curcas as alternative fuel source and income generation depends on the identification of genetically divergent materials of the plant and developing superior planting stocks for farmers. This paper presents genetic diversity assessment of 40 representative accessions drawn from 90 accessions collected from ten regions of Ghana based on their seed yield performance. Random Amplified Polymorphic DNA (RAPD) analysis on the 40 accessions with ten primers revealed an average polymorphism of 24.99%. Genotype Genotype*Environmental biplot analysis which incorporates divergence effects due to genotype (PC1) and interactions between genotype and field parameters (PC2) was 44.7%. Hence the RAPD information indicates narrow genetic diversity among the accessions used in the study and J. curcas germplasm in Ghana. It is therefore recommended that local germplasm of J. curcas should be officially conserved and immediate efforts be made to widen the genetic base through research and introduction from other regions.     

冰雪灾害对森林土壤性质的影响

冰雪灾害是一种常见的自然灾害,易对森林造成巨大破坏。在全球变化加剧的背景下,冰雪灾害发生的频率和强度呈现上升趋势。文中综述了冰雪灾害后森林土壤物理性质、土壤化学性质、土壤微生物群落和土壤酶活性的变化,以便为受损森林生态系统的修复提供参考。今后的研究热点是加强对灾后森林养分循环、土壤微生物和土壤种子库的长期研究,开展土壤微生物群落、土壤呼吸和土壤理化性质相互关系及作用机理研究,运用3S技术监测不同立地条件下土壤灾后动态变化、建立更科学精准的受灾森林生态系统评估体系,以及建立生态修复模型预测冰雪灾害后的森林恢复过程。     

Characteristics of carbon and nitrogen of soil microbial biomass and their relationships with soil nutrients in Cunninghamia lanceolata plantations

The soil microbial biomass and nutrient status under the native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem (in Hunan Province, midland of China) were examined in this study. The results showed that after the native broadleaved forest was replaced by mono-cultured C. lanceolata or C. lanceolata, soil microbial biomass and nutrient pool decreased significantly. In the 0–10 cm soil layer, the concentrations of soil microbial carbon and nitrogen in the broadleaved forest were 800.5 and 84.5 mg/kg, respectively. These were 1.90 and 1.03 times as much as those in the first rotation of the C. lanceolata plantation, and 2.16 and 1.27 times as much as those in the second rotation of the plantation, respectively. While in the 10–20 cm soil layer, the microbial carbon and nitrogen in the broadleaved forest were 475.4 and 63.3 mg/kg, respectively. These were 1.86 and 1.60 times as much as those in the first rotation, and 2.11 and 1.76 times as much as those in the second rotation, respectively. Soil nutrient pools, such as total nitrogen, total potassium, NH₄ ⁺-N, and available potassium, also declined after the C. lanceolata plantation replaced the native broadleaved forest, or Chinese fir was planted continuously. Less litter and slower decay rate in pure Chinese fir plantation were the crucial factors leading to the decrease of soil microbial biomass and nutrient pool in this area. Human disturbance, especially slash-burning and site preparation, was another factor leading to the decrease. There were significant positive correlations between soil microbial carbon and nitrogen and soil nutrients. To improve soil quality and maintain sustainable productivity, some measures, including planting mixed conifer with hardwood, preserving residues after harvest, and adopting scientific site preparation, should be taken. Translated from Chinese Journal of Applied Ecology, 2006, 17(12): 2,292–2,296 [译自: 应用生态学报]     

麻疯树BRI1基因的鉴定及其在不同发育时期花蕾中的表达分析

[目的]研究油菜素内酯受体BRI1的同源基因(JcBRI1)在麻疯树花发育过程中的作用。[方法]利用RT-PCR技术克隆JcBRI1基因的CDS,以pET-30a(+)质粒为框架构建原核表达载体转化至大肠杆菌进行诱导表达,随后利用LC-MS/MS对表达产物进行质谱鉴定,并以氨基酸序列为基础分析JcBRI1蛋白质结构。利用荧光定量PCR分析麻疯树JcBRI1基因在雌雄花发育的关键时期的表达水平,初步确定其在麻疯树花发育过程中的表达模式。[结果]克隆获得了JcBRI1基因的CDS,长度为3 591 bp。SDS-PAGE检测结果表明:JcBRI1基因在大肠杆菌BL21(DE3)和Rosetta(DE3)中均能表达,但在低温环境的表达量更高。原核表达产物的LC-MS/MS鉴定结果表明:JcBRI1氨基酸序列与预期的一致,JcBRI1基因的表达产物为麻疯树BRI1蛋白。对JcBRI1在麻疯树花器官不同发育时期的表达水平进行检测分析,结果表明:JcBRI1基因的表达量在雌花发育的第一个时期即大孢子母细胞时期就达到了最高值,在随后几个时期持续下调;然而,其在雄花各个时期的表达量并无明显差异,表明其很有可能参与了麻疯树雌花大孢子母细胞发育过程。[结论]麻疯树JcBRI1基因为LRR-RLKs家族成员BRI1的同源基因,很有可能参与麻疯树雌花大孢子母细胞的发育过程,至于JcBRI1在麻疯树大孢子母细胞发育过程中的具体作用机制还需进一步研究。     

细菌肥料对湿地松幼龄林生长及土壤性质的影响

[目的]通过研究细菌肥料对湿地松幼龄林生长及对土壤养分、微生物群落功能多样性和酶活性的影响,为细菌肥料对湿地松土壤改良的应用提供参考,以期在促进湿地松生长及改良土壤的同时保持良好的生态环境。[方法]2016年7月在江西省分宜县山下林场采用随机区组设计,设置3个区组,3个处理,分别为细菌肥料处理、基质对照处理及不添加任何肥料的空白对照处理。2017年11月测量湿地松的株高和地径,采用5点取样法采集土壤样品,测定土壤密度、毛管孔隙度、非毛管孔隙度、最大持水量、有机质、有效磷、速效钾、水解性氮以及过氧化氢酶、磷酸酶、蔗糖酶和脲酶活性,用Biolog-ECO板分析微生物群落功能多样性。[结果]细菌肥料显著促进了湿地松幼苗株高和地径的增长,空白对照、基质对照处理和细菌肥料处理地径的相对增长量分别为98.27%、105.53%和123.09%,株高的相对增长量分别为55.69%、66.56%和85.18%,细菌肥料处理和基质对照处理均降低了土壤密度,增加了土壤毛管孔隙度、非毛管孔隙度以及最大持水量,改善了土壤物理性质,但细菌肥料处理的作用更显著。细菌肥料和基质对照均提高了湿地松土壤的有机质、有效磷、水解性氮以及速效钾含量,但细菌肥料处理与空白对照处理之间在4种养分含量上均存在显著性差异,而基质对照与空白对照之间只在有机质含量上存在显著性差异。细菌肥料处理显著提高了土壤磷酸酶、过氧化氢酶、蔗糖酶以及脲酶活性,细菌肥料还使土壤微生物群落代谢活性、对6类碳源(碳水化合物类、氨基酸类、羧酸类、多聚物类、酚酸类和胺类)的利用能力以及土壤微生物群落的Shannon多样性指数(H)、Simpson优势度指数(D)、Pielou均匀度指数(J)和丰富度指数(S)显著提高,基质对照也促进了上述指标的升高,但效果并不显著。[结论]细菌肥料处理和基质对照处理均可以促进湿地松幼苗的生长,提高湿地松土壤有机质、有效磷、速效钾以及水解性氮的含量,同时使土壤过氧化氢酶、磷酸酶、蔗糖酶以及脲酶活性升高,提高土壤微生物多样性、均匀度、丰富度以及优势度指数,提高了微生物对单一碳源的利用能力以及代谢活性,但细菌肥料的作用效果更为显著,基质对照的作用效果并不显著。     

Effects of different vegetation restoration models on soil microbial biomass in eroded hilly Loess Plateau, China

Vegetation restoration is a key measure to improve the eco-environment in Loess Plateau, China. In order to find the effect of soil microbial biomass under different vegetation restoration models in this region, six trial sites located in Zhifanggou watershed were selected in this study. Results showed that soil microbial biomass, microbial respiration and physical and chemical properties increased apparently. After 30 years of vegetation restoration, soil microbial biomass C, N, P (SMBC, SMBN, SMBP) and microbial respiration, increased by 109.01%–144.22%, 34.17%–117.09%, 31.79%–79.94% and 26.78%–87.59% respectively, as compared with the farmland. However, metabolic quotient declined dramatically by 57.45%–77.49%. Effects of different models of vegetation restoration are different on improving the properties of soil. In general, mixed stands of Pinus tabulaeformis-Amorpha fruticosa and Robinia pseudoacacia-A. fruticosa had the most remarkable effect, followed by R. pseudoacacia and Caragana korshinkii, fallow land and P. tabulaeformis was the lowest. Restoration of mixed forest had greater effective than pure forest in eroded Hilly Loess Plateau. The significant relationships were observed among SMBC, SMBP, microbial respiration, and physical and chemical properties of soil. It was concluded that microbial biomass can be used as indicators of soil quality. __________ Translated from Journal of Natural Resources, 2007, 22(1): 20–27 [译自: 自然资源学报]     

Changes in soil physicochemical and microbial properties along elevation gradients in two forest soils

The effects of the interaction between tree species composition and altitude on soil microbial properties are poorly understood. In this study, soil samples (0–20?cm) were collected in August 2011 from Betula platyphylla and Picea crassifolia forests along two different altitudinal gradients. Soil microbial activity and biomass were measured using Biolog-ECO plates and phospholipid fatty acid analysis. Both of the forest soils were characterized by a significantly lower soil pH (p?p?相似文献   

杉木凋落物土壤生态功能研究进展

凋落物作为连接植物与土壤的基本载体,在养分循环中起着至关重要的作用。目前国内外的研究主要集中于自然或人工林凋落物的产量、养分含量、能量流动及碳循环等方面,而针对杉木凋落物的土壤生态功能并未深入探究。通过查阅大量文献,在前人研究的基础上,文中简述了杉木凋落物的分解特性,详尽地阐述了杉木凋落物对于土壤物理、化学性质及土壤生物的影响,并在现有研究分析的基础上对今后凋落物研究的方向进行了展望。