苔藓泥炭对高含沙土壤水动力学参数的影响

从水动力学角度探讨了苔藓泥炭对高含沙(沙土比7∶3)土壤水分运动的影响。结果表明:随着苔藓泥炭含量增加,土壤饱和含水量、毛管含水量和田间持水量均线性增加;土壤持水曲线逐渐上移,持水性和供水能力明显增加,当吸力增加到0.5×105Pa时,各处理土壤的比水容量均出现10-2数级;原状土饱和导水率随泥炭含量增加呈先增后降的变化趋势,在30 g/kg达到最大值,而压实后的饱和导水率呈逐渐下降趋势。     

不同苔垫和基质对白发藓断茎繁殖的影响

为了筛选白发藓繁殖的适宜台垫和基质,提高白发藓人工繁殖率和质量,将白发藓分别在5种苔垫(苔纤布、毛毡布、无纺布、海绵、三维苔纤布)和6种基质(陶粒、鹿沼土、蛭石、植金石、赤玉土、珍珠岩)上断茎繁殖120 d,考察白发藓的生物量、颜色评分、叶绿素含量和覆盖度4个指标。结果表明：白发藓在苔纤布上生物量为2064 g/m2,颜色评分为4.33分,叶绿素含量为2.16 mg/L,覆盖度为50.33%;在赤玉土上生物量为9072 g/m2,颜色评分为8分,叶绿素含量为3.15 mg/L,覆盖度为83.31%,白发藓生长适宜的苔垫和基质分别为苔纤布和赤玉土。     

黄土高原不同发育阶段生物结皮的导水和持水特征

为探明黄土高原不同发育阶段生物结皮对土壤导水和持水特性的影响，以裸沙和不同发育阶段生物结皮（藻结皮、藻-藓混生结皮、藓结皮）为研究对象， 分别采用定水头法和威尔科克斯法对其导水和持水特性进行了测定。结果表明， 在0~10 cm土层， 生物结皮显著降低了土壤饱和导水率， 藻结皮、藻-藓混生结皮和藓结皮土壤的饱和导水率较裸沙分别平均下降了59.3%，62.9%和27.6%；同时， 其水分入渗参数（初始入渗速率、稳定入渗速率、平均入渗速率和累积入渗量）较裸沙分别平均降低了37.7%、54.3%和18.4%， 延缓了土壤水分入渗过程；此外， 3种发育阶段生物结皮的田间持水量（体积含水量）较裸沙分别增加了0.97、1.10和0.70倍， 退水过程（0~120 h）的平均土壤体积含水量分别增加了1.14、1.40和0.74倍。与裸沙相比， 不同发育阶段的生物结皮均显著降低了土壤导水率， 同时提高了土壤持水性；其中藻-藓混生结皮对土壤导水和持水性能的影响大于藻结皮和藓结皮， 其主要原因可能是不同发育阶段生物结皮中非维管束植物和微生物的群落结构存在差异。综上， 随着生物结皮由藻向藓的发育演替， 其土壤导水性呈现先降低后增加的趋势， 而土壤持水性表现为先增加后降低的变化规律。     

苔藓覆盖对喀斯特林地碳酸盐岩红土剥蚀过程的影响

为探究苔藓覆盖对喀斯特山地土壤剥蚀过程影响的机理,通过野外采集原状土样,结合上方来水冲刷剥蚀试验,分析了不同坡度(5°,20°)与不同土壤含水率(饱和含水率、田间含水率)条件下苔藓盖度与土壤分离能力间的定量关系,解析了坡面流水力特征参数对苔藓覆盖的响应规律.结果表明:在5°和20°坡度下,苔藓覆盖下饱和土壤的土壤剥蚀率...     

保定室外绿墙火焰南天竹的生理变化研究

为了研究越夏期间,保定市室外绿墙上火焰南天竹的生长状态,对自然区域生长基质为草炭、水苔的火焰南天竹及防寒区域生长基质为草炭、水苔的火焰南天竹进行生理指标测定,并用隶属函数对其进行综合评价.结果 表明:绿墙上日平均光照强度变化范围为0.38～20860.76 Lx,基质日均温度变化范围为6.22～29.55℃,日均湿度变化范围为12.74％～26.40％时,火焰南天竹叶绿素含量及保护酶活性变化规律为升一降;MDA变化规律为降-升-降;营养物质变化规律为升-降-升.自然区域草炭、自然区域水苔、防寒区域草炭、防寒区域水苔基质处理下火焰南天竹叶绿素含量均值分别比CK增加了26.21％、13.71％、66.13％、50.81％;SOD均值分别比CK增加了22.27％、10.44％、37.79％、27.96％;POD均值分别比CK增加了33.22％、15.16％、66.45％、48.19％;可溶性糖含量均值分别比CK增加了53.45％、33.47％、14.53％、89.44％;可溶性蛋白含量均值分别比CK增加了14.22％、6.77％、28.33％、21.69％;MDA含量均值分别比CK降低了31.52％、14.63％、50.84％、35.48％.防寒区域火焰南天竹叶绿素、SOD、POD、可溶性糖、可溶性蛋白含量均值分别比自然区域增加了32.10％、14.20％、26.68％、51.51％、13.14％,MDA含量均值下降了21.62％.各处理下火焰南天竹抗性由强到弱依次为防寒区域草炭基质、防寒区域水苔基质、自然区域草炭基质、自然区域水苔基质.综上所述,防寒区域草炭基质处理最有利于火焰南天竹生长.     

祁连山青海云杉林苔藓枯落物分布与水文特性

对祁连山中段青海云杉林苔藓枯落物分布与水文特性能进行了试验研究。结果表明,试验流域苔藓枯落物层分布与组成存在明显差异,15个样地平均厚度8.2 cm,厚度最大达13.7 cm,最薄仅1.5 cm,相差近10倍;苔藓枯落物中未分解成分较多,占总量的42.8%;半分解和已分解成分较少,分别占23.8%和33.4%。其最大持水率在271.1%~418.2%之间变化,平均为319.8%,青海云杉林区苔藓枯落物层的最大持水量约为其自身干重的3倍左右;最大持水量变化范围在7.6~59.1 mm,平均为36.4mm。经2004年测定,青海云杉样地内苔藓枯落物层平均厚度约9.7 cm,总降水量为178.7 mm,截留量为57.8 mm,占穿透降水的32.34%。     

Grazing or Not Grazing: Implications for Ecosystem Services Provided by Biocrusts in Mediterranean Cork Oak Woodlands

Livestock grazing is one of the most common practices in managed woodlands affecting the abundance and diversity of plant and soil communities. While grazing effects have been studied thoroughly in vascular plants, little is known about grazing consequences for soil lichens and mosses (“biocrusts”) in managed woodlands. However, these complex communities have critical contributions to soil functioning in drylands. We evaluated grazing effects on biocrust abundance and functional composition in Mediterranean cork‐oak woodlands under long‐term grazing and after 7 and 17 years of grazing exclusion. We found four main groups in the region regarding the functional trait ‘growth form’: fruticose and foliose lichens, and short and tall mosses. Each group presented different water absorption and retention capacity, and showed group‐specific effects on soil water and temperature. Fruticose lichens were the most sensitive group to grazing, decreasing dramatically in cover with grazing (~7 times). Also, this group presented higher water retention capacity (~19 h), together with a consistent reducing effect on soil temperature along the grazing gradient (up to 0·9 °C). The shift in biocrust abundance and functional composition under grazing pressure has direct consequences in microclimate regulation, and is likely to influence other ecosystem processes such as CO₂ fixation, soil surface protection and habitat provision. In particular, microclimate regulation may affect cork‐oak regeneration processes, which is one of the main concerns in managed woodlands. Copyright © 2016 John Wiley & Sons, Ltd.     

聚丙烯酰胺与苔藓对幼龄锥栗园土壤侵蚀的影响

采用聚丙烯酰胺(PAM)和苔藓为材料,利用径流小区试验,观测其对幼林锥栗园土壤侵蚀的影响,分析其在3种雨型下径流量与入渗量、含沙量与产沙量以及侵蚀泥沙机械组成的变化结果表明,3种雨型顺坡和梯田的径流量关系为对照＞ PAM与苔藓混合处理＞PAM处理＞苔藓处理,入渗量为苔藓处理的小区最大;PAM处理的产沙量最少,顺坡长历时降雨条件下苔藓处理降低含沙量的效果更加明显;梅雨产沙主要以粘粒和粉粒为主,雷阵雨和台风雨产沙沙粒比例明显增加,PAM与苔藓混合处理阻止园大颗粒土壤的流失最为有效     

Critical values of alternative organic amendments on kiwi seedling growth

The present research was conducted to explore the impact of alternative organic amendments on physicochemical properties of soil and their critical value for kiwi seedlings growth. The experiment was laid out in completely randomized design with 3 replications and 20 seedlings per replication. The highest pH (8.0) was recorded in T3 (compost + silt) and the highest electrical conductivity (EC) of 5.91 dS/m, organic matter (24.11%), organic carbon (13.99%), organic nitrogen (1.51%) were recorded in T8 (compost + peat moss (PM) + leaf manure) and the highest soil porosity (SP) (45.95%) and lowest bulk density (0.67) were recorded in T4 (PM + garden soil (GS)). EC higher than 1.99 and SP (45.95%) were found critical and adversely affected seedling survival. The highest plant height (103 and 93 cm), number of leaves (23 and 20), number of first-order lateral roots (NFLRM) (9 and 8.5), whole seedling fresh mass (75 and 72 g), fresh root mass (FRM) (35 and 35 g), shoot fresh mass (46 and 40 g), root collar diameter (RCD) (13 and 12 mm), and shoot diameter (10 and 9 mm) were recorded in T5 (compost + GS) and T7 (compost + PM + GS). Strong and positive correlations were observed among NFLRP, RFM, and RCD (R² = 0.89 and 0.96) and all the above-ground seedling traits (R² = 0.86–0.98). It is concluded that compost is a good soil amendment for producing good quality graftable kiwi seedlings and evaluation of seedling root system architecture could be used to predict the potential and success of seedlings in the field.