高原地区多年生与一年生禾本科牧草混播效果     

宋理明  李红梅  魏永林  马宗泰  严应存  徐有绪  朱宝文 《草业科学》2009,26(5):135-138

在高原地区退耕还草示范种植中,利用牧区广泛种植的一年生禾本科牧草燕麦Avena sativa与进口的多年生禾本科牧草细茎冰草Efymus trachycaulum混播。结果表明：燕麦和细茎冰草混播既能克服单一种植多年生禾本科牧草时的杂草危害问题,也能使退耕当年就获得较好的经济效益,解决了种植当年的收成问题,使项目建设的效益及早得到体现。第1年燕麦开花期鲜草产量为2.49 kg/m2, 细茎冰草第2年能够良好生长,第2年细茎冰草开花期鲜草产量为1.48 kg/m2,生长后期鲜草产量为1.76 kg/m2。  相似文献   

Divergent effects of defoliation intensity and frequency on tiller growth and production dynamics of Pascopyrum smithii and Hesperostipa comata          下载免费PDF全文

T. S. Broadbent  E. W. Bork  W. D. Willms 《Grass and Forage Science》2018,73(2):532-543

Rotational stocking theoretically enables regrazing of regrowth, but regrowth may be limited in xerophytic vegetation. We tested the hypothesis that regrowth would be slow and fixed in Hesperostipa comata (a caespitose, drought‐tolerant grass), while growth would be flexible in Pascopyrum smithii (a rhizomatous, less drought‐tolerant grass) under increasing defoliation and moisture, by assessing tiller growth rates, population dynamics and plant yield on marked plants in a Dry Mixed Grass prairie. Plots were clipped in late summer to simulate a deferred control, or intermittently during the growing season (May–August) at high intensity–low frequency (HILF), low intensity–high frequency (LIHF) or high intensity–high frequency and crossed with two water treatments (ambient and addition) in both a xeric upland and a mesic lowland. Growing season defoliation increased tiller growth rates of P. smithii in the upland, whereas HILF and LIHF reduced growth in the lowland. All defoliation regimes increased tiller growth for H. comata. Tiller populations of H. comata increased with frequent defoliation, while tiller populations of P. smithii decreased regardless of defoliation regime. Frequent defoliation, regardless of intensity, reduced yield relative to the deferred control for both grasses. While water addition consistently increased growth rates and reduced differences in tiller number among defoliation treatments, the regrowth of both grasses remained similar under varied defoliation with ambient moisture. High moisture conditions also promoted regrowth more in P. smithii compared to H. comata. In summary, neither grass species displayed an inherently fixed or flexible tiller or plant yield response in response to defoliation or moisture.  相似文献   

Interacting effects of soil degradation and precipitation on plant productivity in NE Patagonia,Argentina     

María Victoria Campanella  César Mario Rostagno  Lina Sonia Videla  Alejandro Jorge Bisigato 《Arid Land Research and Management》2016,30(1):79-88

Our objective was to examine the effects of inter-annual variation of precipitation on productivity of two dominant species (Chuquiraga avellanedae, an evergreen shrub, and Nassella tenuis, a perennial grass) in two communities of contrasting soil degradation: a herbaceous steppe with shrubs (HSS) and a degraded shrub steppe (SS). Data were collected during two consecutive years with different annual precipitation. Aboveground productivity was determined nondestructively using a double sampling approach. The number of inflorescences per plant was recorded too. Perennial grass productivity was lower in SS than in HSS in both years, while shrub productivity was lower in SS only during the year of below average precipitation. With rising precipitation the perennial grass increased the number of inflorescences while the evergreen shrub augmented vegetative biomass. In summary, the effects of precipitation on plant productivity are community dependent; abiotic factors, such as superficial and sub-superficial soil characteristics, and biotic factors, such as leaf area index (LAI) or tussock sizes, may interact to influence the responses of species to precipitation. Our results suggest that if precipitation increased, this would favor the dominance of shrubs over grasses.  相似文献   

Invasive and native plant responses to shrubland fuel reduction: comparing prescribed fire, mastication, and treatment season     

Jennifer B. Potts 《Biological conservation》2009,142(8):1657-1664

Fuel reduction in the wildland-urban interface is a widely used international strategy for assisting human communities regarding wildfire threats, but very little research has examined whether certain fuel reduction methods and their seasonal timing promote nonnative invasion. To address this issue, we evaluated nonnative and native plant response to five of the most commonly-practiced shrubland fuel reduction methods in Mediterranean climates, including (a) fall prescribed fire, (b) winter prescribed fire, (c) spring prescribed fire, (d) fall mastication (slashing) and (e) spring mastication. Treatments were replicated four times in mature northern California chaparral and surveyed for three years after treatment; treatment type was randomly assigned. We found that the effects of treatment type (fire/mastication) were more apparent than the effects of treatment season (fall/winter/spring), but there were some differences among seasons of prescribed fire. Mastication treatments had the highest number of nonnative invasive species. Mastication treatments also had 34% higher nonnative annual grass abundance than the fire treatments. Winter and spring prescribed fire treatments were most resistant to nonnative invasion since these areas had the fewest nonnative species, lowest nonnative species abundances, and highest relative proportions of native plants. In shrublands where controlling nonnative annual grass is an important objective, managers should consider cool season prescribed fire as a viable fuel reduction treatment. In cases where prescribed fire is not feasible, mastication provides an alternative that can exacerbate nonnative grass production in the short term but may maintain native plant seedbanks over the long term if the site remains undisturbed for several decades. Results from this study could be applicable to other areas of Mediterranean shrublands.  相似文献   

冷季型草坪草的生态养护技术     

孙淑琴  杨秀荣  田涛  刘宝生 《天津农业科学》2011,17(4):124-126

针对冷季型草坪草的生长特性,详尽阐述了草坪草的生态养护技术,包括修剪、施肥、灌水等技术措施,以提高现代化草坪养护管理水平.  相似文献   

几种高大禾草热值和灰分动态变化研究   总被引：7，自引：1，他引：6  

宁祖林  陈慧娟  王珠娜  张卓文  邱迎君 《草业学报》2010,19(2):241-247

对3种C₃类植物(芦竹、菅、芦苇)与5种C₄类植物(五节芒、芒、岗柴、斑茅、南荻)不同器官热值和灰分含量的月变化进行了研究,并探讨了其应用前景,为禾草类能源植物筛选评价提供科学依据。结果表明,1)8种高大禾草灰分含量存在差异,且具明显的季节性变化;C₃类植物平均灰分含量分别为:芦竹(7.17±1.09)%、菅(6.33±0.60)%、芦苇(7.89±1.09)%;C₄类植物平均灰分含量分别为:五节芒(4.92±1.38)%、芒(6.27±0.94)%、岗柴(6.99±1.13)%、斑茅(5.13±0.88)%、南荻(5.10±0.82)%。2)C₃类植物中芦竹干重热值较高,C₄类植物中五节芒、芒、斑茅、南荻的干重热值比较接近,无显著差异,岗柴干重热值最低。3)芦竹的干重热值与灰分含量有显著线性相关(P＜0.05),五节芒、芦苇的干重热值与灰分含量有极显著线性相关(P＜0.01),而菅、芒、岗柴、斑茅、南荻的干重热值与灰分含量无相关性(P＞0.05)。4)C₃类植物平均去灰分热值分别为:芦竹(19.01±0.27)kJ/g、菅(18.58±0.31)kJ/g、芦苇(18.72±0.23)kJ/g;C₄类植物平均去灰分热值分别为:五节芒(18.52±0.32)kJ/g、芒(18.69±0.47)kJ/g、岗柴(18.54±0.33)kJ/g、斑茅(18.48±0.41)kJ/g、南荻(18.49±0.37)kJ/g,灰分含量不同,导致去灰分热值与干重热值的月变化趋势不同。  相似文献   

土壤干旱对黄土高原4个乡土禾草生长及水分利用特性的影响   总被引：2，自引：1，他引：1  

郭颖  韩蕊莲  梁宗锁 《草业学报》2010,19(2):21-30

应用盆栽试验,人工控制土壤水分含量对黄土高原4个乡土禾草长芒草、冰草、无芒隐子草、白羊草的生长及水分利用特性进行了研究。结果表明,随干旱胁迫程度加剧,各草种耗水量明显减少;不同草种单株耗水量差异明显,表现为:白羊草>冰草>无芒隐子草>长芒草,最高日、旬、月耗水量差异明显,中度和重度水分亏缺下的最高耗水日比适宜水分下的提前10d左右。1d中的最大耗水高峰随着土壤含水量的降低有提前的趋势。4个草种株高生长和单叶叶面积明显受土壤水分含量影响,均表现为:适宜水分>中度干旱>重度干旱,土壤干旱下长芒草和无芒隐子草受抑制程度显著大于冰草和白羊草;随干旱胁迫程度的加剧和干旱时间的延长,长芒草和无芒隐子草的叶片组织含水量和叶片相对含水量明显降低,冰草和白羊草则一直能维持较高含水量,且下降幅度小,稳定性好;长芒草和无芒隐子草的水分利用效率(wateruseefficiency,WUE)随干旱加剧而降低,两者属于低耗水、低WUE草种,冰草和白羊草在中度干旱下WUE最高,相比白羊草,冰草属于低耗水、高WUE草种,白羊草属于高耗水、高WUE草种。  相似文献   

Influence of different forage grasses on nitrate capture and leaching loss from a pumice soil   总被引：1，自引：0，他引：1  

A. J. Popay  J. R. Crush 《Grass and Forage Science》2010,65(1):28-37

Nitrogen (N) uptake and loss in leachate from a pulse of ¹⁵N-labelled synthetic cow urine applied to a pumice soil were compared in a glasshouse lysimeter experiment among the grass species, Agrostis capillaris , Dactylis glomerata , Phalaris aquatica , Lolium multiflorum , L . perenne and a L . multiflorum/A. capillaris mixture. In addition, four L. perenne treatments investigated the effect of infection by Neotyphodium lolii strains. Leachate volumes and leachate nitrate concentrations were measured. At final harvest 24 weeks after sowing, dry matter (DM) mass of shoots and roots, plant N and ¹⁵N contents, soil residual mineral N, and root diameters and lengths were measured. Endophyte had no effect on plant or nitrate variables. Lysimeters planted with L . perenne (pooled endophyte treatments) leached 48 mg of NO₃-N compared with <3 mg N for the other grasses. Recovery of ¹⁵N was highest in A. capillaris (0·99), followed by D. glomerata and P. aquatica (0·89), the L . multiflorum / A. capillaris mixture (0·87), L . multiflorum (0·60) and L . perenne (0·44). Low ¹⁵N recoveries and high leaching losses from L . perenne were associated with low plant and root masses of DM and low rooting depth. High aerial mass of DM, root systems extending below 20 cm and high root masses of DM in lysimeters with A. capillaris , P. aquatica and D. glomerata contributed to a high rate of nitrate interception by these species and low leachate losses. The L . multifloru m/ A. capillaris mixture was intermediate between the two species for most of the variables measured.  相似文献   

应用Logistic方程研究优良冷季型观赏草抗热性   总被引：1，自引：0，他引：1  

高鹤  宗俊勤  郭爱桂  刘建秀 《草业科学》2010,27(10):27-30

高温是热带和亚热带地区冷季型观赏草生长发育的最大限制因子。本研究以叶片为材料,用改良电导法测定配合Logistic方程求拐点温度的方法测定了6种冷季型观赏草的高温半致死温度(LT50)。结果表明,经等梯度的高温处理后,待试材料叶片细胞伤害率和温度之间呈现明显的"S"形曲线,符合Logistic方程,拟合度较好。抗热性排序为:宽叶苔草(Carexsiderosticta)(LT50=53.5℃)皱苞苔草(C.chungii)(LT50=52.5℃)发状苔草(C.comans)(LT50=51.5℃)棕榈叶苔草(C.muskingumensis)(LT50=48.4℃)蓝灰石竹(Dianthus gratianopolitanus)(LT50=46.3℃)花叶虉草(Phalaris arundinacea)(LT50=44.8℃)。通过对供试材料在南京地区越夏情况的田间观测,发现宽叶苔草、皱苞苔草、发状苔草的长势良好,外观无任何变化,因此认为这3种观赏草的抗热性较强。  相似文献   

Accumulation and composition of total organic carbon in reclaimed coal mine lands     

G. K. Ganjegunte  A. F. Wick  P. D. Stahl  G. F. Vance 《Land Degradation \u0026amp; Development》2009,20(2):156-175

Reclaimed coal mine lands have the potential to sequester atmospheric carbon (C); however, limited information exists for the western USA coalfields. This study was carried out on two chronosequences (BA‐C₃ grasses and DJ‐shrubs) of reclaimed sites at two surface coal mines to determine the effects of vegetation, soil texture, and lignin content on soil total organic carbon (TOC) accumulations. In the BA chronosequence, TOC increased over 26 years at an average rate of 0·52 Mg C ha⁻¹ yr⁻¹ in the 0–30 cm depth and was significantly correlated with clay content. Comparison between < 1 and 16‐year‐old stockpile soils indicated TOC content did not differ significantly. In the DJ chronosequence, TOC content in the 0–30 cm depth declined from 31·3 Mg ha⁻¹ in 5‐year‐old soils to 23·4 Mg ha⁻¹ in 16‐year‐old soils. The C:N ratios suggested that some (up to 2·0 per cent) of the TOC was potentially derived from coal particles in these reclaimed soils. Soil total N (TN) contents followed a similar trend as TOC with TOC and TN concentrations strongly correlated. Lignin contents in TOC of all reclaimed soils and topsoil stockpiles (TSs) were higher than that of nearby undisturbed soils, indicating the recalcitrant nature of TOC in reclaimed soils and/or possibly the slow recovery of lignin degrading organism. Results indicated that TOC accumulations in DJ were largely controlled by its composition, particular lignin content. In BA sites TOC accumulation was strongly influenced by both clay and lignin contents. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献