332 resultados para Poa pratensis


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background Pollens of subtropical grasses, Bahia (Paspalum notatum), Johnson (Sorghum halepense), and Bermuda (Cynodon dactylon), are common causes of respiratory allergies in subtropical regions worldwide. Objective To evaluate IgE cross-reactivity of grass pollen (GP) found in subtropical and temperate areas. Methods Case and control serum samples from 83 individuals from the subtropical region of Queensland were tested for IgE reactivity with GP extracts by enzyme-linked immunosorbent assay. A randomly sampled subset of 21 serum samples from patients with subtropical GP allergy were examined by ImmunoCAP and cross-inhibition assays. Results Fifty-four patients with allergic rhinitis and GP allergy had higher IgE reactivity with P notatum and C dactylon than with a mixture of 5 temperate GPs. For 90% of 21 GP allergic serum samples, P notatum, S halepense, or C dactylon specific IgE concentrations were higher than temperate GP specific IgE, and GP specific IgE had higher correlations of subtropical GP (r = 0.771-0.950) than temperate GP (r = 0.317-0.677). In most patients (71%-100%), IgE with P notatum, S halepense, or C dactylon GPs was inhibited better by subtropical GP than temperate GP. When the temperate GP mixture achieved 50% inhibition of IgE with subtropical GP, there was a 39- to 67-fold difference in concentrations giving 50% inhibition and significant differences in maximum inhibition for S halepense and P notatum GP relative to temperate GP. Conclusion Patients living in a subtropical region had species specific IgE recognition of subtropical GP. Most GP allergic patients in Queensland would benefit from allergen specific immunotherapy with a standardized content of subtropical GP allergens.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both types of subtropical grass pollens to achieve optimal diagnosis and treatment of patients with allergic respiratory disease in subtropical regions of the world. © 2014 John Wiley & Sons Ltd.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

本文选取不同放牧率下的优势植物为研究对象,主要从植物解剖结构和化学成分方面,对内蒙古典型草原和北美混合普列里草原的放牧演替机制进行探讨,这将有助于进一步揭示放牧演替过程及其主要植物对放牧的适应机理。具体研究结果如下: 1. 长期不同放牧率的放牧(内蒙古典型草原区放牧15年和混合普列里草原放牧19年)对所有物种(IMGERS的羊草(Leymus chinensis)、冰草(Agropyron cristatum)、糙隐子草(Cleistogenes squarrosa)、扁蓿豆(Melissitus rutenica)、小叶锦鸡儿(Caragana microphylla)、冷蒿(Artemisia frigida)和星毛委陵菜(Potentilla acaulis)和CGREC的Artemisia frgida ,Poa pratensis, Agropyron smithii,Solidago rigida, Helianthus rigidus和Symphoricarpos occidentalis)叶片的角质层厚度、表皮细胞面积、叶肉细胞面积、栅栏/海绵组织厚度、叶片厚度、中脉厚度均产生显著影响;放牧显著影响了两个研究区不同生活型功能群植物叶片的角质层厚度、表皮细胞面积、叶肉面积、栅栏/海绵组织和中脉厚度。内蒙古典型草原研究区草本植物功能群的叶片下角质层厚度、栅栏/海绵组织厚度显著大于灌木功能群,而美国混合普列里草原研究区,草本植物功能群的叶片下角质层厚度、表皮细胞面积、叶肉细胞面积、栅栏/海绵组织厚度、叶片厚度、中脉厚度均显著大于灌木功能群。 2. 内蒙古典型草原研究区放牧率显著影响了糙隐子草和小叶锦鸡儿的比叶面积(SLA);在美国混合普列里草原研究区,放牧率显著影响了冷蒿SLA。但对生活型功能群的SLA影响不显著。 3. 内蒙古典型草原研究区放牧对物种叶片叶绿素含量、纤维素含量影响显著,放牧仅显著增加了扁蓿豆叶片的含氮量。美国混合普列里草原研究区物种叶片的全碳、干物质、酸性洗涤纤维、叶绿素a+b含量受放牧率的显著影响。两研究区放牧率对叶片叶绿素a+b含量影响显著。放牧率也显著影响了不同生活型功能群的全碳含量和叶绿素a+b含量。 4. 两研究区叶片表皮细胞面积和叶肉细胞面积无牧和重牧下显著正相关,表皮细胞面积和叶片厚度在轻牧下显著正相关,叶肉细胞面积和叶片厚度在无牧、中牧和重牧下显著正相关,比叶面积和叶绿素a+b含量在轻牧下显著正相关。扁蓿豆叶片的表皮细胞面积和叶肉细胞面积间存在显著的正相关,其全碳含量和叶绿素a+b含量间存在显著的正相关;Artemisia frgida叶片的角质层厚度和叶片厚度间显著正相关,Poa pratensis叶片的角质层厚度和表皮细胞面积间显著负相关,Solidago rigida叶片表皮细胞面积和光合速率显著正相关。Helianthus rigidus叶片叶肉细胞面积和叶片厚度显著负相关。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

利用种子和胚分别在两种培养基K3和K5诱导产生了早熟禾(Poa pratensis L.)一个品种Mado的胚性愈伤组织。K3培养基含有10.0μmol/L的二氯苯氧乙酸(2,4-D)、0.5μmol/L的苄氨基嘌呤(BAP)。K5培养基是K3另加0.5μmol/L的硫酸铜。光照条件为20~30μmol·m~(-2)·s~(-1)、16h光照、8h黑暗。温度保持在24℃。用携有bar基因和gus基因的pDM805质粒转化的农杆菌AGL1对胚性愈伤组织进行转化。共得到4个转基因株系。影响转基因效率的主要因素

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0.5 mumol/L) and K5 which was the K3 medium supplemented with cupric sulfa (0.5 mumol/L) under dim-light condition (20-30 mumol.m(-2).s-1, 16 h light) at 24 degreesC. Embryogenic calli were transformed with plasmids pDM805 Carring bar and gus genes, Which was mediated by an Agrobacterium strain AGL1, four transgenic lines were obtained. The important factors that affect the transformation efficiency and obtain desirable number of transgenic plants included: (1) the quality of embryogenic calli; (2) light condition and time of co-cultivation; (3) concentration of antibiotics used for suppressing the overgrowth of Agrobacterium in the course of transformed plant regeneration; (4) selection pressure, etc. The micro nutrient of cupric had significant influence on the quality of embryogenic calli. This presentation is the first successful protocol of Kentucky bluegrass transformation mediated by Agrobacterium.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

2003 年3 月到2006 年3 月,我们对世界上了解最少的鹤类,也是唯一一种越冬和繁 殖都在高原湿地内进行的鹤类——黑颈鹤(Grus nigrcollis)东部种群的野外繁殖生态、越冬 生态和迁徙路线等方面作了重点研究。研究时间分为三个阶段:2003 年3 月到2005 年6 月,在黑颈鹤的繁殖地点四川省若尔盖湿地国家级自然保护区内(102°29′-102°59′E, 33°25′-34°00′N)进行,对在若尔盖湿地内繁殖和度夏黑颈鹤的种群现状,繁殖习 性,繁殖季节黑颈鹤栖息地选择利用及牛羊放牧活动对黑颈鹤栖息地利用的影响,繁殖黑 颈鹤鸟巢及筑巢栖息地选择的特点等内容进行了研究;第二阶段从2004 年10 月到2006 年3 月,在黑颈鹤东部种群重要的越冬地云南省大山包黑颈鹤国家级自然保护区内 (103o14’55”—103o18’38”E, 27º18’38”—27o28’42”N)进行,对越冬黑颈鹤的越冬习性,栖息 地选择利用,白昼时间行为分配进行了研究;第三阶段2005 年2 月-3 月、2006 年3 月,在云南省大山包保护区和贵州省草海黑颈鹤国家级自然保护区,给8 只黑颈鹤佩戴卫 星发射器,第一次在中国利用卫星技术来跟踪候鸟的迁徙,对东部黑颈鹤越冬种群的迁徙 路线进行求证和新的探索,并利用卫星数据进行黑颈鹤在繁殖地和越冬地活动特点的分 析。 在2004 年5 月围绕整个若尔盖湿地自然保护区内和周边地区繁殖和度夏黑颈鹤的现 状调查中,共统计到黑颈鹤320 只和巢6 个,112 只黑颈鹤(35%)和5 个鸟巢分布在保护 区内,主要集中在保护区内水域和沼泽面积较大的两块核心区内,208 只黑颈鹤(65%)和1 个鸟巢分布在保护区外,主要分布在黄河、白河沿线地区,其中在白河和黄河交界的地 区,记录有163 只黑颈鹤;本次调查中,黑颈鹤利用最多的是在黄河和白河交界处的农 地,其次是沼泽和河岸地带,最少的是草甸和退化草甸;不论是在保护区内还是在保护区 外,湿地生境都体现了黑颈鹤在栖息地选择时的重要性;在花湖繁殖地,黑颈鹤繁殖种群 和巢在3 年内呈现下降和减少的趋势,湿地面积的缩小和退化可能是主要的原因。 繁殖习性:根据繁殖期间产卵,幼鹤出壳等事件行为发生的时间将整个繁殖季节划分 为繁殖前期(到达之日到5 月12 日),繁殖中期(5 月13 日到6 月18 日)和繁殖后期(6 月19 日到离开)。黑颈鹤3 月下旬即从越冬地返回繁殖地点花湖,首先到达的是带有幼鹤的繁 殖家庭鹤,之后才是集群鹤,这种返回的过程持续到5 月初。在繁殖前期,黑颈鹤种群数 量经历一个增加的过程,在此期间,花湖的黑颈鹤种群数量较低(27),繁殖黑颈鹤先后经历家庭解体 (Family breakup),建立繁殖领域,完成交配,筑巢等行为,进入繁殖中期 后,花湖的黑颈鹤种群数量整体呈现下降趋势,并在6 月的第一周达到最低,繁殖中期黑 颈鹤的种群比前期稍高(29),与繁殖相关的行为在整个繁殖季节达到最高(51%),进入繁 殖后期,随着幼鹤出壳和成鹤维持领域能力的降低,花湖周围的黑颈鹤种群数量再次增 加,并在以后的2 个月内维持在较高的数量(56),到9 月中旬,黑颈鹤开始迁徙,4 周 后,所有的鹤都离开繁殖地花湖。在繁殖期间,被驱逐出领域的幼鹤与非繁殖的成鹤形成 集群在繁殖地周围游荡,集群在各个时期都存在,只是在繁殖前期最多(2 群/周),繁殖中 期和繁殖后期为1 群/周,群内个体数量在繁殖中期最高(26 只/群),在繁殖前期和中期分 别是6 和8 只/群,不同时期的群体和群体规模都存在显著差异;黑颈鹤的交配发起者是 雌鹤,交配的成功率为60%,雄鹤的无应答和不成熟的交配经验是交配失败的主要原 因,80%的交配发生在上午,交配成功率为58.3%,20%的交配发生在下午,成功率为 66.7%,黑颈鹤的交配主要发生在4 月到5 月上旬之间,66.7%的交配发生在这一时期, 成功率为80%,之后到6 月上旬的交配仅有33.3%,成功率仅有20%,随着时间的推移, 交配的成功率降低(从4 月的100%减少到5 月份的45%和6 月份的0);黑颈鹤的窝卵数是 2 枚,卵重207 克,卵长径和短径分别是107 和58 毫米,孵卵期为31 天,幼鹤的出壳率 为100%,但二个月后的死亡率达到31.2%,之后的幼鹤未观察到死亡,幼鹤出壳后两个 月内的死亡率可能是制约种群增长的一个原因;繁殖期间黑颈鹤食物以蕨麻(Potentilla anserina)、荸荠(Heleocharis dulcis)、委陵菜属(Comarum)、草地早熟禾(Poa pratensis)、眼 子菜属(Potamageton)、蒲公英(Taraxacum mongolicum)等植物的花、果、茎等为主,但也 取食包括无脊椎动物如蝗虫(Chorthippus hsiai),粪金龟(Geotrupes sp.),椭圆萝卜螺(Radix swinboi)和耳萝卜螺(Radix ouricuaria),以及脊椎动物黑唇鼠兔(Ochotona curizoniae)、红 脚鹬(Tringa totanus)、黑水鸡(Callinula chloropus)、小..(Tachgbaptus ruficollis)、黄河裸 鲤(Gymnocypris pylzovi)等,取食动物性食物可能是补充繁殖所耗费的巨大能量和为迁徙 储备能量;繁殖季节黑颈鹤的主要时间分配在取食和繁殖上,分别占45%和28%,其余 依次为运动10%、护理9%、警戒6%、静息1%和其它1%,不同的繁殖阶段,除了运动 和其它行为外,其余各种行为的时间分配存在显著差异,各行为频次以警戒最高(43 次/小 时),其余依次为取食(31 次/小时)、护理(17 次/小时)、运动(11 次/小时)、繁殖(5 次/小 时)、其它(1 次/小时)和静息(1 次/小时),除了其它行为外,各繁殖阶段行为发生频次差异 显著,各行为的持续时间以繁殖最多(189 秒/次),其次为取食(53 秒/次)、静息(50 秒/次)、 运动(33 秒/次)、其它(22 秒/次)和护理(19 秒/次),在一天中,黑颈鹤各行为分配随时间的历家庭解体 (Family breakup),建立繁殖领域,完成交配,筑巢等行为,进入繁殖中期 后,花湖的黑颈鹤种群数量整体呈现下降趋势,并在6 月的第一周达到最低,繁殖中期黑 颈鹤的种群比前期稍高(29),与繁殖相关的行为在整个繁殖季节达到最高(51%),进入繁 殖后期,随着幼鹤出壳和成鹤维持领域能力的降低,花湖周围的黑颈鹤种群数量再次增 加,并在以后的2 个月内维持在较高的数量(56),到9 月中旬,黑颈鹤开始迁徙,4 周 后,所有的鹤都离开繁殖地花湖。在繁殖期间,被驱逐出领域的幼鹤与非繁殖的成鹤形成 集群在繁殖地周围游荡,集群在各个时期都存在,只是在繁殖前期最多(2 群/周),繁殖中 期和繁殖后期为1 群/周,群内个体数量在繁殖中期最高(26 只/群),在繁殖前期和中期分 别是6 和8 只/群,不同时期的群体和群体规模都存在显著差异;黑颈鹤的交配发起者是 雌鹤,交配的成功率为60%,雄鹤的无应答和不成熟的交配经验是交配失败的主要原 因,80%的交配发生在上午,交配成功率为58.3%,20%的交配发生在下午,成功率为 66.7%,黑颈鹤的交配主要发生在4 月到5 月上旬之间,66.7%的交配发生在这一时期, 成功率为80%,之后到6 月上旬的交配仅有33.3%,成功率仅有20%,随着时间的推移, 交配的成功率降低(从4 月的100%减少到5 月份的45%和6 月份的0);黑颈鹤的窝卵数是 2 枚,卵重207 克,卵长径和短径分别是107 和58 毫米,孵卵期为31 天,幼鹤的出壳率 为100%,但二个月后的死亡率达到31.2%,之后的幼鹤未观察到死亡,幼鹤出壳后两个 月内的死亡率可能是制约种群增长的一个原因;繁殖期间黑颈鹤食物以蕨麻(Potentilla anserina)、荸荠(Heleocharis dulcis)、委陵菜属(Comarum)、草地早熟禾(Poa pratensis)、眼 子菜属(Potamageton)、蒲公英(Taraxacum mongolicum)等植物的花、果、茎等为主,但也 取食包括无脊椎动物如蝗虫(Chorthippus hsiai),粪金龟(Geotrupes sp.),椭圆萝卜螺(Radix swinboi)和耳萝卜螺(Radix ouricuaria),以及脊椎动物黑唇鼠兔(Ochotona curizoniae)、红 脚鹬(Tringa totanus)、黑水鸡(Callinula chloropus)、小..(Tachgbaptus ruficollis)、黄河裸 鲤(Gymnocypris pylzovi)等,取食动物性食物可能是补充繁殖所耗费的巨大能量和为迁徙 储备能量;繁殖季节黑颈鹤的主要时间分配在取食和繁殖上,分别占45%和28%,其余 依次为运动10%、护理9%、警戒6%、静息1%和其它1%,不同的繁殖阶段,除了运动 和其它行为外,其余各种行为的时间分配存在显著差异,各行为频次以警戒最高(43 次/小 时),其余依次为取食(31 次/小时)、护理(17 次/小时)、运动(11 次/小时)、繁殖(5 次/小 时)、其它(1 次/小时)和静息(1 次/小时),除了其它行为外,各繁殖阶段行为发生频次差异 显著,各行为的持续时间以繁殖最多(189 秒/次),其次为取食(53 秒/次)、静息(50 秒/次)、 运动(33 秒/次)、其它(22 秒/次)和护理(19 秒/次),在一天中,黑颈鹤各行为分配随时间的历家庭解体 (Family breakup),建立繁殖领域,完成交配,筑巢等行为,进入繁殖中期 后,花湖的黑颈鹤种群数量整体呈现下降趋势,并在6 月的第一周达到最低,繁殖中期黑 颈鹤的种群比前期稍高(29),与繁殖相关的行为在整个繁殖季节达到最高(51%),进入繁 殖后期,随着幼鹤出壳和成鹤维持领域能力的降低,花湖周围的黑颈鹤种群数量再次增 加,并在以后的2 个月内维持在较高的数量(56),到9 月中旬,黑颈鹤开始迁徙,4 周 后,所有的鹤都离开繁殖地花湖。在繁殖期间,被驱逐出领域的幼鹤与非繁殖的成鹤形成 集群在繁殖地周围游荡,集群在各个时期都存在,只是在繁殖前期最多(2 群/周),繁殖中 期和繁殖后期为1 群/周,群内个体数量在繁殖中期最高(26 只/群),在繁殖前期和中期分 别是6 和8 只/群,不同时期的群体和群体规模都存在显著差异;黑颈鹤的交配发起者是 雌鹤,交配的成功率为60%,雄鹤的无应答和不成熟的交配经验是交配失败的主要原 因,80%的交配发生在上午,交配成功率为58.3%,20%的交配发生在下午,成功率为 66.7%,黑颈鹤的交配主要发生在4 月到5 月上旬之间,66.7%的交配发生在这一时期, 成功率为80%,之后到6 月上旬的交配仅有33.3%,成功率仅有20%,随着时间的推移, 交配的成功率降低(从4 月的100%减少到5 月份的45%和6 月份的0);黑颈鹤的窝卵数是 2 枚,卵重207 克,卵长径和短径分别是107 和58 毫米,孵卵期为31 天,幼鹤的出壳率 为100%,但二个月后的死亡率达到31.2%,之后的幼鹤未观察到死亡,幼鹤出壳后两个 月内的死亡率可能是制约种群增长的一个原因;繁殖期间黑颈鹤食物以蕨麻(Potentilla anserina)、荸荠(Heleocharis dulcis)、委陵菜属(Comarum)、草地早熟禾(Poa pratensis)、眼 子菜属(Potamageton)、蒲公英(Taraxacum mongolicum)等植物的花、果、茎等为主,但也 取食包括无脊椎动物如蝗虫(Chorthippus hsiai),粪金龟(Geotrupes sp.),椭圆萝卜螺(Radix swinboi)和耳萝卜螺(Radix ouricuaria),以及脊椎动物黑唇鼠兔(Ochotona curizoniae)、红 脚鹬(Tringa totanus)、黑水鸡(Callinula chloropus)、小..(Tachgbaptus ruficollis)、黄河裸 鲤(Gymnocypris pylzovi)等,取食动物性食物可能是补充繁殖所耗费的巨大能量和为迁徙 储备能量;繁殖季节黑颈鹤的主要时间分配在取食和繁殖上,分别占45%和28%,其余 依次为运动10%、护理9%、警戒6%、静息1%和其它1%,不同的繁殖阶段,除了运动 和其它行为外,其余各种行为的时间分配存在显著差异,各行为频次以警戒最高(43 次/小 时),其余依次为取食(31 次/小时)、护理(17 次/小时)、运动(11 次/小时)、繁殖(5 次/小 时)、其它(1 次/小时)和静息(1 次/小时),除了其它行为外,各繁殖阶段行为发生频次差异 显著,各行为的持续时间以繁殖最多(189 秒/次),其次为取食(53 秒/次)、静息(50 秒/次)、 运动(33 秒/次)、其它(22 秒/次)和护理(19 秒/次),在一天中,黑颈鹤各行为分配随时间的历家庭解体 (Family breakup),建立繁殖领域,完成交配,筑巢等行为,进入繁殖中期 后,花湖的黑颈鹤种群数量整体呈现下降趋势,并在6 月的第一周达到最低,繁殖中期黑 颈鹤的种群比前期稍高(29),与繁殖相关的行为在整个繁殖季节达到最高(51%),进入繁 殖后期,随着幼鹤出壳和成鹤维持领域能力的降低,花湖周围的黑颈鹤种群数量再次增 加,并在以后的2 个月内维持在较高的数量(56),到9 月中旬,黑颈鹤开始迁徙,4 周 后,所有的鹤都离开繁殖地花湖。在繁殖期间,被驱逐出领域的幼鹤与非繁殖的成鹤形成 集群在繁殖地周围游荡,集群在各个时期都存在,只是在繁殖前期最多(2 群/周),繁殖中 期和繁殖后期为1 群/周,群内个体数量在繁殖中期最高(26 只/群),在繁殖前期和中期分 别是6 和8 只/群,不同时期的群体和群体规模都存在显著差异;黑颈鹤的交配发起者是 雌鹤,交配的成功率为60%,雄鹤的无应答和不成熟的交配经验是交配失败的主要原 因,80%的交配发生在上午,交配成功率为58.3%,20%的交配发生在下午,成功率为 66.7%,黑颈鹤的交配主要发生在4 月到5 月上旬之间,66.7%的交配发生在这一时期, 成功率为80%,之后到6 月上旬的交配仅有33.3%,成功率仅有20%,随着时间的推移, 交配的成功率降低(从4 月的100%减少到5 月份的45%和6 月份的0);黑颈鹤的窝卵数是 2 枚,卵重207 克,卵长径和短径分别是107 和58 毫米,孵卵期为31 天,幼鹤的出壳率 为100%,但二个月后的死亡率达到31.2%,之后的幼鹤未观察到死亡,幼鹤出壳后两个 月内的死亡率可能是制约种群增长的一个原因;繁殖期间黑颈鹤食物以蕨麻(Potentilla anserina)、荸荠(Heleocharis dulcis)、委陵菜属(Comarum)、草地早熟禾(Poa pratensis)、眼 子菜属(Potamageton)、蒲公英(Taraxacum mongolicum)等植物的花、果、茎等为主,但也 取食包括无脊椎动物如蝗虫(Chorthippus hsiai),粪金龟(Geotrupes sp.),椭圆萝卜螺(Radix swinboi)和耳萝卜螺(Radix ouricuaria),以及脊椎动物黑唇鼠兔(Ochotona curizoniae)、红 脚鹬(Tringa totanus)、黑水鸡(Callinula chloropus)、小..(Tachgbaptus ruficollis)、黄河裸 鲤(Gymnocypris pylzovi)等,取食动物性食物可能是补充繁殖所耗费的巨大能量和为迁徙 储备能量;繁殖季节黑颈鹤的主要时间分配在取食和繁殖上,分别占45%和28%,其余 依次为运动10%、护理9%、警戒6%、静息1%和其它1%,不同的繁殖阶段,除了运动 和其它行为外,其余各种行为的时间分配存在显著差异,各行为频次以警戒最高(43 次/小 时),其余依次为取食(31 次/小时)、护理(17 次/小时)、运动(11 次/小时)、繁殖(5 次/小 时)、其它(1 次/小时)和静息(1 次/小时),除了其它行为外,各繁殖阶段行为发生频次差异 显著,各行为的持续时间以繁殖最多(189 秒/次),其次为取食(53 秒/次)、静息(50 秒/次)、 运动(33 秒/次)、其它(22 秒/次)和护理(19 秒/次),在一天中,黑颈鹤各行为分配随时间的历家庭解体 (Family breakup),建立繁殖领域,完成交配,筑巢等行为,进入繁殖中期 后,花湖的黑颈鹤种群数量整体呈现下降趋势,并在6 月的第一周达到最低,繁殖中期黑 颈鹤的种群比前期稍高(29),与繁殖相关的行为在整个繁殖季节达到最高(51%),进入繁 殖后期,随着幼鹤出壳和成鹤维持领域能力的降低,花湖周围的黑颈鹤种群数量再次增 加,并在以后的2 个月内维持在较高的数量(56),到9 月中旬,黑颈鹤开始迁徙,4 周 后,所有的鹤都离开繁殖地花湖。在繁殖期间,被驱逐出领域的幼鹤与非繁殖的成鹤形成 集群在繁殖地周围游荡,集群在各个时期都存在,只是在繁殖前期最多(2 群/周),繁殖中 期和繁殖后期为1 群/周,群内个体数量在繁殖中期最高(26 只/群),在繁殖前期和中期分 别是6 和8 只/群,不同时期的群体和群体规模都存在显著差异;黑颈鹤的交配发起者是 雌鹤,交配的成功率为60%,雄鹤的无应答和不成熟的交配经验是交配失败的主要原 因,80%的交配发生在上午,交配成功率为58.3%,20%的交配发生在下午,成功率为 66.7%,黑颈鹤的交配主要发生在4 月到5 月上旬之间,66.7%的交配发生在这一时期, 成功率为80%,之后到6 月上旬的交配仅有33.3%,成功率仅有20%,随着时间的推移, 交配的成功率降低(从4 月的100%减少到5 月份的45%和6 月份的0);黑颈鹤的窝卵数是 2 枚,卵重207 克,卵长径和短径分别是107 和58 毫米,孵卵期为31 天,幼鹤的出壳率 为100%,但二个月后的死亡率达到31.2%,之后的幼鹤未观察到死亡,幼鹤出壳后两个 月内的死亡率可能是制约种群增长的一个原因;繁殖期间黑颈鹤食物以蕨麻(Potentilla anserina)、荸荠(Heleocharis dulcis)、委陵菜属(Comarum)、草地早熟禾(Poa pratensis)、眼 子菜属(Potamageton)、蒲公英(Taraxacum mongolicum)等植物的花、果、茎等为主,但也 取食包括无脊椎动物如蝗虫(Chorthippus hsiai),粪金龟(Geotrupes sp.),椭圆萝卜螺(Radix swinboi)和耳萝卜螺(Radix ouricuaria),以及脊椎动物黑唇鼠兔(Ochotona curizoniae)、红 脚鹬(Tringa totanus)、黑水鸡(Callinula chloropus)、小..(Tachgbaptus ruficollis)、黄河裸 鲤(Gymnocypris pylzovi)等,取食动物性食物可能是补充繁殖所耗费的巨大能量和为迁徙 储备能量;繁殖季节黑颈鹤的主要时间分配在取食和繁殖上,分别占45%和28%,其余 依次为运动10%、护理9%、警戒6%、静息1%和其它1%,不同的繁殖阶段,除了运动 和其它行为外,其余各种行为的时间分配存在显著差异,各行为频次以警戒最高(43 次/小 时),其余依次为取食(31 次/小时)、护理(17 次/小时)、运动(11 次/小时)、繁殖(5 次/小 时)、其它(1 次/小时)和静息(1 次/小时),除了其它行为外,各繁殖阶段行为发生频次差异 显著,各行为的持续时间以繁殖最多(189 秒/次),其次为取食(53 秒/次)、静息(50 秒/次)、 运动(33 秒/次)、其它(22 秒/次)和护理(19 秒/次),在一天中,黑颈鹤各行为分配随时间的变化而体现较为明显的节律性,这可能与青藏高原恶劣的自然环境(如高辐射和热量的不 均匀分布)有关。 2003 年4 月1 日到10 月13 日,在花湖对黑颈鹤繁殖栖息地选择和放牧活动对黑颈鹤 取食栖息地选择的影响进行研究。研究区域内,按照从湖心向外的方向,将黑颈鹤繁殖期 间所使用的生境划分为4 种类型,即:湖心沼泽,浅水沼泽,草甸和退化草甸。繁殖期 间,黑颈鹤对各种栖息地利用的强度并非一致。湖心沼泽和湖岸沼泽是整个繁殖季节黑颈 鹤青睐的栖息地,是黑颈鹤筑巢和休息的地点,草甸和退化草甸是黑颈鹤主要的取食地 点,但在整个季节内都不是黑颈鹤青睐的栖息地类型,虽然在繁殖后期,在草甸和退化草 甸上活动的黑颈鹤明显增加。在有牛羊放牧时,大多数的繁殖鹤(49.7%)选择在距离湖边 100m 内的区域活动,而非繁殖鹤则主要在0-100m 区域(33.3%)和>400m 的区域(28.1%) 活动,在牛羊集中活动的200-400m 区域,两种鹤都选择避开,牛羊离开繁殖地点后, 黑颈鹤有向远离湖边方向扩散的趋势,多数的繁殖鹤(54.9%)和非繁殖鹤(52.3%)都在 >400m 的区域活动,虽然距离水面的距离在繁殖鹤活动地点的选择上有一定的影响,但 过度放牧的牛羊的确压缩了繁殖鹤和非繁殖鹤的活动空间。因此,在繁殖地来说,减少沼 泽区域的开发,对特定区域放牧活动的控制,加强沼泽生境的恢复,是保证黑颈鹤成功繁 殖的关键。 2003 年5 月到2005 年6 月,在若尔盖湿地内找到黑颈鹤的巢21 个。黑颈鹤的巢有3 种,分别是芦苇巢(3 个)、地上巢(14 个)和泥堆巢(4 个),地上巢巢参数最小,芦苇巢的巢 参数最大;所有的巢都分布在湿地环境中,包括湖泊,沼泽和河流三种栖息地,巢在这些 栖息地中的分布也不是均匀的,湖泊中分布的巢最多,湖泊是黑颈鹤筑巢首选的栖息地, 但每年在此类生境中筑巢的黑颈鹤正在减少,黑颈鹤选择避开利用沼泽区域作为筑巢的栖 息地,黑颈鹤对河流区域的利用按照获得性进行;筑巢栖息地周围1 米外的草高和巢的暴 露与否、巢距离水面的距离和巢所在草岛的面积、巢周围的水深成为影响巢址选择的三个 主要生态因子,反映了隐蔽度、筑巢栖息地的质量和到达巢的难易程度是黑颈鹤选择巢址 的主要因素;在不同的微生境中,巢的参数不同,湖泊中的巢参数最大,湖泊中的巢比沼 泽中的巢更长、更宽和更高,而巢周围的水深差距不明显,湖泊中的巢要比河流中的巢短 径大,巢周的水深要比河流中的巢要稍浅,但巢长径和巢高差异不显著,沼泽和河流环境 中的巢参数没有明显的差异;巢周围有一定的水深是巢址选择时最为基本的条件;与其他 地区黑颈鹤的巢比较,若尔盖湿地中的巢要更小,但巢周围的水深要更深,这可能与不同 地点的植被、地理环境以及不同的人为干扰强度有关;若尔盖湿地内黑颈鹤巢栖息地的选择是黑颈鹤对正在变化中栖息地的妥协结果,保留有适宜于繁殖的小面积沼泽区域对黑颈 鹤的繁殖也很重要。 2004 年10 月到2006 年3 月,在大山包保护区对越冬黑颈鹤的生态进行研究。我们 将整个越冬季节划分为越冬早期(10 月-12 月),越冬中期(1 月-2 月)和越冬后期(3 月-4 月)。保护区内黑颈鹤利用的栖息地划分为4 种类型,即:浅水生境,沼泽区域,草甸和 耕地。首先到达越冬地的仍然是家庭鹤,其次是集群鹤。大山包是黑颈鹤春季迁徙和秋季 迁徙的迁徙中转站,迁徙的高峰在12 月和3 月出现,在草海越冬的黑颈鹤在春季迁徙时 经过大山包,并在此停留8 天。大山包也是黑颈鹤的越冬地点,有大约900 只的黑颈鹤在 此越冬。黑颈鹤的配对主要发生在越冬中期,黑颈鹤家庭的解体(Family breakup)发生在繁 殖后期的3 月和4 月间,成鹤以放弃幼鹤离开越冬地而达到家庭的解体。整个越冬季节, 黑颈鹤对各种栖息地的利用强度并不是一致的。湿地(浅水区域和沼泽)是黑颈鹤整个冬天 青睐的生境(除了越冬后期对水域区域利用低外),而耕地是越冬早期和越冬中期黑颈鹤的 主要取食地点,在越冬后期,草甸则成为黑颈鹤的主要取食地点。在整个冬天,幼鹤将 72.2%的时间用在取食,将6.8%的时间用在警戒,将18.6%的时间用在修整行为上,用在 其它行为上的时间为2.4%,而成鹤用在这些行为上的时间分配是63.9%,11%,22.8%和 2.3%。随着时间的推移,成鹤减少取食的时间,与之对应而增加了修整行为的比例,而 幼鹤的各行为变化没有规律性。是否具有越冬经验和不同的生态需求导致了成鹤和幼鹤的 不同时间分配。正是由于具有越冬经验,成鹤能够有效地调整不同行为的分配,幼鹤虽然 没有越冬经验,但在成鹤的照顾下,幼鹤有足够长的时间去取食,成鹤和幼鹤采取了不同 的越冬策略。正是具有越冬经验,成鹤的白昼行为分配呈现出一定的规律性,如取食行为 在早晚各自有一个取食峰值,而修整行为在中午最高等,而由于缺乏越冬经验和行为受到 成鹤的影响较大,幼鹤的行为节律规律性不是很强。 2005 年2-3 月和2006 年3 月,在大山包和贵州草海给8 只黑颈鹤放置了卫星发射器 以确定这两个地点的黑颈鹤的迁徙路线和新的繁殖地点。东部越冬种群的黑颈鹤迁徙时间 2-4 天,中途停歇3-4 个点,迁徙平均距离为622 公里,黑颈鹤迁徙时首先飞越金沙 江,向北偏西方向穿过和停歇于四川省的凉山山脉,到达凉山、邛崃山和大雪山脉交界的 地方,然后沿着大渡河河谷向北迁徙,到达包括四川省的若尔盖县、红原县、阿坝县、松 潘县,以及甘肃省玛曲县的若尔盖湿地内。与1993 年环志证实的迁徙路线比较,黑颈鹤 迁徙时明显避开了海拔较低、人口稠密的四川盆地,选择了沿着青藏高原东缘向四川盆地 过渡的高山峡谷地带飞行,沿着大渡河河谷进行迁徙。2 只黑颈鹤的信号在大渡河河谷区域消失,这个地点对于黑颈鹤的迁徙和保护有重要的意义。到达繁殖地后,黑颈鹤的活动 范围在5 月达到最大,此后逐渐减小,在8 月份活动范围减小到最小,之后,活动面积又 逐渐增大,并在迁徙前达到最高。在繁殖地,黑颈鹤每天的活动范围只有不到2km,隔 日的活动范围也不超过3km,结果提示在若尔盖湿地内可能还有更多的黑颈鹤活动。编 号为55984 的黑颈鹤在2005 年11 月和2006 年3 月分别完成从繁殖地返回越冬地和从越 冬地再次到达繁殖地的迁徙过程,在草海环志的64311 在繁殖地若尔盖湿地度过繁殖季节 后又成功返回草海越冬,而64310 在大山包越冬,在若尔盖湿地内度过夏季,在2006 年 11 月又返回草海越冬,其余两只黑颈鹤返回大山包越冬,结果证实1、黑颈鹤迁徙路线、 繁殖地和越冬地选择的稳定性,2、东部黑颈鹤越冬种群存在交流。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Urban populations of Canada geese (Branta canadensis) cause considerable problems when large numbers congregate in parks, playing fields, and backyards. In most cases, geese are drawn to these sites to feed on the lawns. I tested whether geese have feeding preferences for different grass species. Captive Canada geese preferred Kentucky bluegrass (Poa pratensis) and disliked tall fescue (Festuca arundinaceae) over colonial bentgrass (Agrostis tenuis cv. Highland), perennial ryegrass (Lolium perenne), and red fescue (Festuca rubra). They refused to eat some other ground covers such as pachysandra (Pachysandra terminalis) and English ivy (Hedera helix). These results suggest that goose numbers at problem sites could be reduced by changing the ground cover. I also compared the characteristics of foraging sites used by geese to other foraging sites that geese avoided. Occupied sites were more open so that geese had clearer visibility and greater ease in taking off and landing. This suggests that goose numbers at problem sites also could be reduced by planting tall trees to make it harder for the geese to fly away, and planting bushes and hedges to obstruct a goose's visibility.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The response of Kentucky bluegrass (Poa pratensis L.) to potassium (K) fertilization has been inconsistent. The objective of this research was to determine the effects of K fertilization across varying nitrogen (N) rates and clipping management on Kentucky bluegrass clipping yields, quality, tissue K concentrations, apparent N recovery, and N use efficiency. A 2 x 4 x 4 factorial was arranged in a splitplot design and repeated across two years. Main plots were clipping treatments (returned vs. removed) and subplots were N rates (0, 98, 196, and 294 kg ha(-1) yr(-1)) in combination with K rates (0, 81, 162, and 243 kg ha(-1) yr(-1)). There was no positive effect of K on clipping yields and quality even though soil extractable K levels tested low. Higher K rates, however, increased N recovery and use efficiency for all but the highest N rate. Tissue K response to K fertilization was nonlinear. Yield and quality responses were not correlated to tissue K concentration. Nonexchangeable K levels were high in the native soil, and may have provided an additional source of K for bluegrass. The results suggest that extractable K values alone may not adequately predict available K to Kentucky bluegrass in this sandy loam soil.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Nutrient leaching studies are expensive and require expertise in water collection and analyses. Less expensive or easier methods that estimate leaching losses would be desirable. The objective of this study was to determine if anion-exchange membranes (AEMs) and reflectance meters could predict nitrate (NO3-N) leaching losses from a cool-season lawn turf. A two-year field study used an established 90% Kentucky bluegrass (Poa pratensis L.)-10% creeping red fescue (Festuca rubra L.) turf that received 0 to 98 kg N ha-1 month-1, from May through November. Soil monolith lysimeters collected leachate that was analyzed for NO3-N concentration. Soil NO3-N was estimated with AEMs. Spectral reflectance measurements of the turf were obtained with chlorophyll and chroma meters. No significant (p > 0.05) increase in percolate flow-weighted NO3-N concentration (FWC) or mass loss occurred when AEM desorbed soil NO3-N was below 0.84 µg cm-2 d-1. A linear increase in FWC and mass loss (p < 0.0001) occurred, however, when AEM soil NO3-N was above this value. The maximum contaminant level (MCL) for drinking water (10 mg L-1 NO3-N) was reached with an AEM soil NO3-N value of 1.6 µg cm-2 d-1. Maximum meter readings were obtained when AEM soil NO3 N reached or exceeded 2.3 µg cm-2 d-1. As chlorophyll index and hue angle (greenness) increased, there was an increased probability of exceeding the NO3-N MCL. These data suggest that AEMs and reflectance meters can serve as tools to predict NO3-N leaching losses from cool-season lawn turf, and to provide objective guides for N fertilization.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Tissue N analysis a tool available for N management of turfgrass. However, peer-reviewed calibration studies to determine optimum tissue N values are lacking. A field experiment with a mixed cool-season species lawn and a greenhouse experiment with Kentucky bluegrass (Poa pratensis L.) were conducted across 2 yr, each with randomized complete block design. Treatments were N application rates between 0 and 587 kg N ha-1 yr-1. In the field experiment, clipping samples were taken monthly from May to September, dried, ground, and analyzed for total N. Clippings samples were collected one to two mowings after plots were fertilized. Linear plateau models comparing relative clipping yield, Commission Internationale de l' Eclairage hue, and CM1000 index to leaf N concentrations were developed. In the greenhouse experiment, clipping samples were taken every 2 wk from May to October and composited across sample dates for leaf N analysis. Color and clipping yields were related to leaf N concentrations using linear plateau models. These models indicated small marginal improvements in growth or color when leaf N exceeded 30 g kg-1, suggesting that a leaf N test can separate turf with optimum leaf N concentrations from turf with below optimum leaf N concentrations. Plateaus in leaf N concentrations with increasing N fertilizer rates suggest, however, that this test may be unable to identify sites with excess available soil N when turf has been mowed before tissue sampling.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Reinforcement inclusions have been advocated to alleviate wear, compaction, and unstable surfaces in sports fields, but little research on the effects of these materials has been conducted in the USA. Experiments were established on a native silt loam and a sand rootzone matrix, seeded with a Kentucky bluegrass (Poa pratensis L.) blend, at the Joseph Troll Turf Research Center, University of Massachusetts, Amherst, USA to determine the effects of reinforcement inclusions on wear, surface hardness, traction, ball roll, ball bounce resilience, water infiltration rate, soil bulk density, air porosity, total porosity, and root weights. Three types of reinforcement inclusions (Sportgrass, Netlon, Turfgrids) were tested along with a non-reinforced control in a three year study. The treatments were set out in a randomized complete block design with four replications in both soils. No inclusion provided less wear or greater infiltration or air-filled porosity relative to the control. Reinforcement inclusions showed significant differences, however, in surface hardness, traction, and ball roll relative to the control, although this varied with the time of year. Infiltration rates, airfilled porosity, total pore space, bulk density, hardness, traction, ball roll, and ball rebound were greater on the sand rootzone than on the silt loam. Significant correlations were present between soil bulk density, surface hardness, traction, and ball roll. Based on our study, the use of reinforcement inclusions to provide better wear tolerance for sand or native soil athletic fields is not warranted. Certain playing surface characteristics, however, may be slightly improved with the use of reinforcement inclusions. The use of sands for sports surfaces is justified based upon the improvement in playing quality characteristics and soil physical properties important to a good playing surface.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fall season fertilization is a widely recommended practice for turfgrass. Fertilizer applied in the fall, however, may be subject to substantial leaching losses. A field study was conducted in Connecticut to determine the timing effects of fall fertilization on nitrate N (NO3-N) leaching, turf color, shoot density, and root mass of a 90% Kentucky bluegrass (Poa pratensis L.), 10% creeping red fescue (Festuca rubra L.) lawn. Treatments consisted of the date of fall fertilization: 15 September, 15 October, 15 November, 15 December, or control which received no fall fertilizer. Percolate water was collected weekly with soil monolith lysimeters. Mean log10 NO3-N concentrations in percolate were higher for fall fertilized treatments than for the control. Mean NO3-N mass collected in percolate water was linearly related to the date of fertilizer application, with higher NO3-N loss for later application dates. Applying fall fertilizer improved turf color and density but there were no differences in color or density among applications made between 15 October and 15 December. These findings suggest that the current recommendation of applying N in mid- to late November in southern New England may not be compatible with water quality goals.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Ideal nitrogen (N) management for turfgrass supplies sufficient N for high-quality turf without increasing N leaching losses. A greenhouse study was conducted during two 27-week periods to determine if in situ anion exchange membranes (AEMs) could predict nitrate (NO3-N) leaching from a Kentucky bluegrass (Poa pratensis) turf grown on intact soil columns. Treatments consisted of 16 rates of N fertilizer application, from 0 to 98 kg N ha-1 mo-1. Percolate water was collected weekly and analysed for NO3-N. Mean flow-weighted NO3-N concentration and cumulative mass in percolate were exponentially related (pseudo-R2=0.995 and 0.994, respectively) to AEM desorbed soil NO3-N, with a percolate concentration below 10 mg NO3-N L-1 corresponding to an AEM soil NO3-N value of 2.9 micro g cm-2 d-1. Apparent N recovery by turf ranged from 28 to 40% of applied N, with a maximum corresponding to 4.7 micro g cm-2 d-1 AEM soil NO3-N. Turf colour, growth, and chlorophyll index increased with increasing AEM soil NO3-N, but these increases occurred at the expense of increases in NO3-N leaching losses. These results suggest that AEMs might serve as a tool for predicting NO3-N leaching losses from turf.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This data set contains aboveground community biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice in 2004 just prior to mowing (during peak standing biomass in late May and in late August) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in four rectangles of 0.2 x 0.5 m per large plot. The location of these rectangles was assigned prior to each harvest by random selection of coordinates within the core area of the plots (i.e. the central 10 x 15 m). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material (i.e., dead plant material in the data file), and remaining plant material that could not be assigned to any category (i.e., unidentified plant material in the data file). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The data for individual samples and the mean over samples for the biomass measures on the community level are given. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This data set contains aboveground community biomass (Sown plant community, Weed plant community, Dead plant material, and Unidentified plant material; all measured in biomass as dry weight) and species-specific biomass from the sown species of the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Aboveground community biomass was harvested twice in 2007 just prior to mowing (during peak standing biomass in early June and in late August) on all experimental plots of the main experiment. This was done by clipping the vegetation at 3 cm above ground in four (May) or three (August) rectangles of 0.2 x 0.5 m per large plot. The location of these rectangles was assigned prior to each harvest by random selection of coordinates within the core area of the plots (i.e. the central 10 x 15 m). The positions of the rectangles within plots were identical for all plots. The harvested biomass was sorted into categories: individual species for the sown plant species, weed plant species (species not sown at the particular plot), detached dead plant material (i.e., dead plant material in the data file), and remaining plant material that could not be assigned to any category (i.e., unidentified plant material in the data file). All biomass was dried to constant weight (70°C, >= 48 h) and weighed. Sown plant community biomass was calculated as the sum of the biomass of the individual sown species. The data for individual samples and the mean over samples for the biomass measures on the community level are given. Overall, analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity-productivity relationship.