东方百合品种‘西伯利亚’切花生产中替代泥炭的基质研究

以东方百合品种‘西伯利亚’（‘Siberia’）为试材,研究了在混配基质中用麦秆、玉米秆、椰糠、菇渣、豆荚等5种有机废弃物替代泥炭作为栽培基质的可行性。结果表明,5份泥炭︰2份珍珠岩︰1份蛭石︰2份麦秆、4份泥炭︰2份珍珠岩︰1份沙子︰3份玉米秆、2份珍珠岩︰2份蛭石︰3份椰糠︰3份沙子（均为体积比）等3种混配基质的各项理化指标均在无土栽培基质的理想范围内,用其栽培的百合,生长发育综合表现优于目前生产上常用的含70%泥炭的基质,其中又以4份泥炭︰2份珍珠岩︰1份沙子︰3份玉米秆的基质最优。     

碳化谷壳和苔藓在烟草漂浮育苗基质中的应用

为筛选部分替代草炭的材料,减少烤烟漂浮育苗草炭的使用,以烤烟品种K326为材料,以商用基质为对照,分别研究了碳化谷壳和苔藓与珍珠岩、蛭石和草炭不同配比的基质对烟草幼苗农艺性状、光合作用和根系活力的影响。结果表明,加入碳化谷壳和苔藓的基质出苗率和整齐度均强于对照,农艺性状和净光合速率均弱于对照,但C2处理(30%珍珠岩+5%蛭石+30%苔藓+35%草炭)和C1(30%珍珠岩+5%蛭石+10%苔藓+55%草炭)与对照无显著差异,A3处理(30%珍珠岩+5%蛭石+50%碳化谷壳+15%草炭)和C3处理(30%珍珠岩+5%蛭石+50%苔藓+15%草炭)的根系活力和根系形态均强于对照。整体上苔藓替代草炭的潜力更大,但碳化谷壳对烟苗根系的发育更好,替代草炭的潜力较大。     

Weak response of bryophyte assemblages to second commercial thinning in boreal spruce forest of south-central Sweden

Forest management regimes dictate the composition and structure of large parts of the Fennoscandian boreal forest region. The understanding of thinning impacts on understorey plant communities is considerably lower compared to the effects of final felling. We studied the response of bryophyte assemblages to second commercial thinning in spruce-dominated stands sampled to be representative of the dominant forest type of south-central Sweden. Eighteen stands were analysed 6–12 years after second commercial thinning, and were compared with six stands commercially thinned only once, at two spatial scales (0.1 and 0.01?ha), with stand ages varying between 52 and 66 years. We found few strong differences in bryophyte species richness and no differences in bryophyte species composition between stands thinned once or twice. More pioneer species were found in stands thinned only once, a result that needs further study. Species richness declined significantly with time since thinning on both investigated spatial scales. Canopy cover significantly affected the composition of forest floor species. Thinning effects over longer time periods need further study, and also effects in different forest types along productivity gradients. For nature conservation, studies targeted towards thinning response of uncommon species connected to specific habitats and substrates will be essential.     

江西五倍子蚜虫冬寄主的初步研究

五倍子为东南亚特产，具有广泛的应用领域，我国尤以药用名。本报道江西产五倍子种类的同时，记述了江西五倍子蚜虫冬寄主的种类及分布，为本省五倍子生产，提供冬寄主环节的初步依据。     

产自武夷山的江西藓类植物新记录种

报道产自武夷山的江西藓类植物新记录10种,分别是荷包藓(Garckea flexuosa)、银藓(Anomobryum filiforme)、长柄藓(Fleischerobryum longicolle)、卵叶隐蒴藓(Cryphaca obovatocarpa)、粗疣异枝藓(Heterocladium papillosum)、水灰藓(Hygrohypnum luridum)、摩氏长喙藓(Rhynchostegium muelleri)、淡叶偏蒴藓(Ectropothecium dealbatum)、垂枝藓(Rhytidium rugosum)、仰尖拟垂枝藓(Rhytidiadelphus japonicus).摩氏长喙藓也为中国新记录种.荷包藓属、银藓属、长柄藓属、隐蒴藓属、异枝藓属、水灰藓属、垂枝藓属分别是江西藓类植物属的分布新记录.     

贵州斗篷山藓类植物资源调查与区系分析

为给斗篷山地区及贵州省苔藓植物研究提供基础资料,采用野外采集与室内鉴定相结合的方法,对贵州省斗篷山地区苔藓植物资源、物种结构和区系特征进行研究。结果表明：斗篷山共有藓类植物39科97属241种（包括亚种、变种）。其中,粗齿卷柏藓（Racopilum spectabile ）和瘤根真藓（Bryum bornhol-mense ）为贵州省新纪录种。与贵州其他地区相比,斗篷山地区藓类植物相对较多。该地区优势科属的优势明显,优势科有曲尾藓科（Dicranaceae）、青藓科（Brachytheciaceae）和灰藓科（Hypnaceae）等,优势属有凤尾藓属（Fissidens）、棉藓属（Plagiothecium）和青藓属（Brachythecium）等,但单种属和寡种属数量较大。土生群落占优势,石生、水生和树生群落的数量相当。区系地理复杂,分布类型多样,东亚成分占优势,温带成分占据重要比例。     

生物土壤结皮对毛乌素沙地油蒿群落土壤水分的影响

为进一步探究毛乌素沙地油蒿群落内结皮对土壤水分的影响,研究了结皮(地衣结皮和苔藓结皮)未受干扰和移除处理下的土壤水分入渗、蒸发及含水量状况。结果显示:1)两种结皮均对土壤水分入渗具有抑制作用,移除两种结皮后,土壤水分初渗速率、稳渗速率以及累积入渗量均显著增大(P < 0.05);2)结皮对土壤蒸发的影响与结皮类型及蒸发阶段有关,地衣结皮对整个蒸发过程中日蒸发量及蒸发总量无显著影响(P>0.05),而苔藓结皮对土壤日蒸发量的影响在模拟蒸发前期表现为抑制(第1~5天),后期表现为促进(第6~15天),但对总蒸发量的影响不显著(P>0.05);3)总体来看,地衣结皮覆盖区0~40cm土层含水量高于地衣结皮移除区,而苔藓样地规律则相反。从不同土层来看,相比于移除结皮,地衣结皮覆盖区40cm深度以上各层土壤含水量均较高,苔藓结皮覆盖区土壤含水量在5和10cm深度较高,20和40cm较低。研究结果表明,地衣结皮提高了油蒿群落土壤水分有效性,应对其进行保护;苔藓结皮降低了油蒿种群土壤水分有效性,却提高了浅根系草本土壤水分有效性,这是驱动油蒿群落演替的重要因素之一。研究在为毛乌素沙地油蒿群落提供水分管理依据的同时,也从土壤水分方面为该群落的演替提供一定解释。      

Modeling impact of nitrogen carrier and concentration on root substrate pH

We conducted an experiment to quantify the effects on substrate pH from nitrogen (N) carrier and concentration. We used four concentrations of N (3.5–14 mM) and five fractions of ammonium (NH₄⁺) (0–80% NH₄⁺ of total N) that are found in commercially available fertilizers. Fertilizers were applied to fallow 14-cm-diameter pots (1.29 L) filled with a 3 peat:1 perlite (v/v) substrate amended with non-residual powdered calcium carbonate to raise the substrate pH to approximately 6.0. Harvests occurred at 20 and 42 days. Significant effects in the model included main effects of N carrier and N concentration, their squared terms, an interaction effect, and a time × N carrier. The fraction of NH₄⁺ accounted for 45.0% of variation in substrate pH, and N concentration accounted for 1.5% of the total R² of 76.7%. Substrate acidification was likely due to the physiological fertilizer effect and nitrification.     

黄土高原生物结皮斥水性及其沿降水梯度变化特征研究

为探明黄土高原生物结皮土壤斥水性的影响因素及其沿降水梯度的变化特征,在黄土高原沿降水梯度布设了8个采样区,每个采样区选择恢复年限相近的草地或林地,采用滴水穿透时间法和微型盘式入渗仪法测定了生物结皮与无结皮土壤的斥水时间和斥水系数,分析了生物结皮对斥水性的影响及其与结皮特性、土壤属性和年均降水量的相关性。结果表明,与无结皮土壤相比,黄土高原生物结皮土壤的斥水时间和斥水系数分别增加了54.85倍和5.80倍,但两者沿降水梯度的变化规律相似,均呈自南向北先减小、后稳定的变化趋势,且生物结皮土壤斥水性的空间变异性高于无结皮土壤;生物结皮土壤的斥水时间和斥水系数与结皮厚度、粉粒含量、黏粒含量、有机质含量、年均降水量呈显著的正相关关系(P≤0.032),与苔藓生物量和砂粒含量呈显著的负相关关系(P≤0.030);非线性回归表明,生物结皮土壤的斥水时间和斥水系数均可用结皮厚度和苔藓生物量进行模拟(R2=0.97,NSE不小于0.99)。研究表明,黄土高原生物结皮的发育显著增加了土壤斥水性,且斥水性沿降水梯度从南到北呈先减小、后逐渐稳定的空间变化趋势,年均降水量主要通过改变生物结皮厚度、苔藓生物量和有机质含量等理化性质而间接影响土壤斥水性。     

黄土高原藓结皮覆盖土壤的穿透阻力特征及其影响因素

生物结皮的发育显著地影响并改变了表层土壤的理化性状,从而影响土壤穿透阻力。为探明生物结皮层对土壤穿透阻力的影响,针对黄土高原风沙土和黄绵土两种典型土壤,利用高精度土壤贯入仪测定并比较了不同含水量下藓结皮土壤和无结皮土壤的穿透阻力差异,定量分析了藓结皮层对土壤穿透阻力的影响及其与土壤性质(含水量、容重和有机质含量以及颗粒组成)的关系。结果表明:风沙土和黄绵土藓结皮层最大穿透阻力的变化范围为0.38~3.74 MPa和0.43~8.01 MPa,分别为同等深度下无结皮土壤的2.14~9.45倍(P=0.001)和1.38~6.27倍(P=0.051)。藓结皮对风沙土穿透阻力的影响深度为表层2~12 mm(P=0.028),而对黄绵土的影响深度为3~24 mm(随含水量变异较大)。同时,与无结皮土壤的穿透阻力随深度增加而线性增加的趋势不同,藓结皮土壤的穿透阻力随深度增加在结皮层呈先增后减的趋势,在结皮下层呈线性增加的趋势。此外,藓结皮土壤的横向穿透阻力和纵向穿透阻力差异显著(P≤0.03),但在无结皮土壤上差异不显著(P≥0.052)。藓结皮土壤的穿透阻力与含水量呈显著的幂函数关系(P<0.001),与容重、有机质含量以及砂粒含量呈线性关系,这些因素均为藓结皮改变表层土壤穿透阻力的重要途径。