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121.
Many forest herbs show reduced frequency in forests growing on former agricultural land (secondary forests) relative to forests that were never cleared for agriculture (primary forests). To explain this pattern, studies of secondary forest colonization by forest herbs have stressed the role of limited seed dispersal, though environmental conditions may also limit colonization. Here I demonstrate that adult plant performance of Trillium grandiflorum is significantly reduced in secondary vs. primary forests in central New York State, USA. Comparing primary and secondary sites both with relatively high soil pH, T. grandiflorum populations were more dense, and individual plants were larger and more likely to be flowering in primary than secondary forests. Using counts of annual leaf scars on the rhizome, I demonstrate that this result is not due to secondary populations being younger than primary populations. Age-specific leaf area was significantly greater in primary than secondary stands at high soil pH, and the data suggest slightly reduced seed set in secondary stands as well. These results point to a more important role for environmental conditions in limiting forest-herb colonization of secondary forests than has been previously appreciated. Restoration and conservation of forest herbs in post-agricultural forests will require more than simply overcoming dispersal limitation.  相似文献   
122.
Abstract

The current study examined the capacity of different temporary grassland legume–grass mixtures under different N supply levels to supply similar amounts of elements in systems where the herbage is cut for feed. Mixtures showed a good robustness in supplying equal amounts of mineral elements in the combined herbage as well as equal concentrations in dry matter of mineral elements compared with the same species in monocultures. The reasons for the mixed systems to be able to buffer differences in N supply levels as well as different compositions of the mixtures were that legume leaves and stems had similar concentrations of mineral elements, whether in monocultures or in mixtures with grasses. Grasses in mixture with legumes had however higher N, Ca, S, Zn, Cu and tended to have higher Mg concentration, both in stems and leaves, while Mn were less concentrated in mixtures’ dry matter. Further, the mixtures doubled their dry matter accumulation in the two weeks just around grass heading. The systems partly buffered the time-wise differences in the sense that the P accumulation paralleled dry matter but the N was diluted. This was mirrored in a decrease in N concentration and maintenance of the concentration level of P and other elements. As the stem–leaf ratio was higher (p<0.05) in festulolium than in ryegrass and as the stems of festulolium have lower concentrations of N, K, Ca, S, Mg, Fe and Cu than leaves, the mixtures including festulolium had a rapidly declining proportion of these elements in the combined mixtures’ dry matter. Management options in improving the mineral supplies are thus to choose species when establishing the temporary grasslands according to functionality, to manipulate the content of legumes by the N supply level, and to time the harvest of the herbage.  相似文献   
123.
The herbs chicory ( C ichorium intybus L.) and plantain ( P lantago lanceolata L.) are increasingly popular summer forage cropping options for dairy producers. However, the impact of different establishment methods on their productivity is largely unknown. Four establishment methods for chicory and plantain crops sown into non‐cultivated ryegrass pastures in spring were compared. Establishment methods included direct‐drilling or broadcasting seed into existing pastures, with or without herbicide application before sowing in a 2 × 2 factorial design. It was hypothesized that plant establishment and growth would be enhanced by spraying to kill existing ryegrass pasture and direct‐drilling herbs (Spray and Drill, SD) compared with broadcasting seed with no herbicide application (Unsprayed and Broadcast, UB). This hypothesis was supported with an additional 2·1–2·3 t DM ha?1 grown over 201 d from swards established by SD, compared with swards established by UB. The SD method also increased the plant density of the herbs and reduced the proportion of weed species. Spraying and direct drilling is more expensive than broadcasting seed with no herbicide application, but the increase in yield means that extra feed can be supplied at less than half the cost of purchasing the equivalent amount of feed. Therefore, for optimal economic outcomes, chicory and plantain swards should be established by applying herbicide to existing pasture and direct‐drilling seed.  相似文献   
124.
通过中草药混菌发酵的研究,制备新型生物中药,以替代抗生素在畜禽生产中的应用。采用黑曲霉先有氧发酵产纤维素酶、果胶酶破解植物细胞壁,再用植物乳杆菌厌氧发酵酶解,通过单因素试验和正交试验,以纤维素酶活力、果胶酶活力指标,探索中草药混菌发酵的最佳生产工艺。试验结果表明:最佳培养基条件为中草药浓度为10%,葡萄糖添加量为1%,酵母膏添加量为0.2%, K2HPO4添加量为0.1%,有氧发酵温度为30℃,厌氧发酵温度为37℃,好氧厌氧发酵时间比为2?1,总发酵时间为96 h,接种量比例为2%?2%,pH值为5。在比条件下纤维素酶活达到1412.3 U/ml,果胶酶活达到1287.5 U/ml。中草药经混菌发酵后,粗蛋白提高了31.19%,粗脂肪提高了59.11%,Ca、P含量分别提高了50%、85.71%,中性洗涤纤维,酸性洗涤纤维,木质素分别降解了24.21%、12.58%、17.56%。中草药经混菌发酵后,其营养价值有了明显的提高,为新型生物中药的研制及在畜禽生产中的应用提供参考。  相似文献   
125.
Many Chinese herbs and herbal mixtures are fed to domestic animals for their reputed medicinal properties. These herbs could contribute to the intake of essential nutrients and toxic metals, but their composition is mostly unknown. The purpose of this study was to measure major nutrient (crude protein, crude fat, carbohydrate, fibre) and mineral (Ca, P, Mg, K, Na, Fe, Zn, Cu, Mn, Mo, S, Al, Cd, Ni, Pb) concentrations in samples of fourteen combination formulas labelled for veterinary use and commonly administered to horses and dogs. Three single herbs, Bupleurum chinense, Curcuma zedoaria and Astragalus membranaceus, each obtained from several sources, and Yunnan Baiyao, a proprietary hemostatic mixture, were also analysed. Proximate analyses and some mineral concentrations differed (p < 0.05) among single herbs, and high concentrations of several minerals were detected in some herbal combinations. Those containing the highest concentrations [g/kg dry matter (DM)] of calcium (92.4), iron (2.6) and manganese (0.28) could provide >38%, 142% and 96%, respectively, of recommended allowances in adult dogs, and >13%, 122% and 2%, respectively, of maintenance requirements in horses, at the maximum labelled dose assuming complete availability. Concentrations of cadmium, nickel and lead were below published oral tolerance levels. Aluminium concentrations (median 380, maximum 920 mg/kg DM) were higher than has been previously reported in Chinese herbs. These nutrient analyses suggest that herbal combinations marketed to veterinarians, when fed at the maximal labelled dose, are unlikely to produce clinically relevant changes in the dietary intake of essential nutrients. However, small amounts of non‐essential contaminant minerals are present in some formulas, and further research is necessary to understand the significance of this finding.  相似文献   
126.
中草药提取物对板蓝根根腐病菌抑制作用研究   总被引:1,自引:0,他引:1  
测试了123种中草药提取物对茄腐镰刀菌(Fusarium solani)菌落生长及分生孢子萌发的抑制作用。结果表明:提取物浓度为0.01 g/mL时,99种提取物对菌落生长具有显著的抑制作用,其中苦楝皮和威灵仙的抑菌率大于50%,北沙参的抑菌率达到了100%;112种提取物对分生孢子萌发具有显著抑制作用,其中11种提取物的抑制率在50%以上,而且北沙参和牛膝的抑制率达到了100%。将抑制率大于50%的11种提取物稀释为200倍,进行二次筛选,发现苦楝皮和威灵仙2种提取物对菌落生长的抑制作用下降,而北沙参对菌落生长抑菌率仍为100%;11种提取物对分生孢子萌发抑制率下降的幅度在21.59%~47.02%,而北沙参的抑制率最高,为74.50%。北沙参的抑制中浓度(EC50)为3.621 mg/mL。  相似文献   
127.
中草药制剂消痈散对奶牛乳房炎的疗效   总被引:2,自引:0,他引:2  
为了探索中草药对奶牛乳房炎的治疗效果,用中草药制剂消痈散对奶牛乳房炎进行了治疗试验,观察了其疗效.结果表明,消痈散治疗奶牛临床型乳房炎,总有效率为76.9%,完全治愈率为53.8%;而对照青霉素、链霉素组总有效率为92.9%,完全治愈率为64.3%.对隐性乳房炎治疗,青霉素、链霉素组的总有效率和完全治愈率分别为87.2%和66.3%,而用消痈散组分别为94.6%和80.4%.牛奶乳酸菌发酵试验结果表明:经青霉素、链霉素治疗后96 h酸度恢复正常,而用消痈散治疗后48 h就可恢复正常.表明,消痈散治疗奶牛乳房炎对牛奶乳酸菌发酵影响较小.用药后对产奶量进行统计,奶牛饲喂中草药消痈散后奶产量有所增加,增加最多的在用药后15 d,平均每头牛比未用药的增加5 kg.  相似文献   
128.
试验旨在研究鼠李糖乳杆菌发酵中草药复合枯草芽孢杆菌对白羽肉鸡生长后期免疫性能及大肠杆菌感染的影响。选取体重相似、健康状况基本相同的360只1日龄肉鸡随机分成3个组,每组4个重复,每个重复30只。试验预试期7 d,正试期35 d。试验Ⅰ组为阳性对照组,试验Ⅱ组为阴性对照组,均饲喂基础日粮,试验Ⅲ组在基础饲料中添加1%发酵中草药制剂,且试验Ⅱ、Ⅲ组在肉鸡35日龄时腹腔注射大肠杆菌菌悬液1 mL,连续攻毒2 d,测定肉鸡死亡率、免疫器官指数、盲肠菌群含量、免疫球蛋白水平和白介素含量。结果表明,腹腔注射大肠杆菌造成鸡大量死亡,试验Ⅱ组高达75.00%,显著高于试验Ⅰ、Ⅲ组(P < 0.05),使用发酵中草药微生态制剂后鸡死亡率显著下降(P < 0.05),仅有23.33%;注射大肠杆菌后试验Ⅲ组脾脏指数和法氏囊指数显著升高(P < 0.05),但使用发酵中草药微生态制剂后脾脏指数接近于试验Ⅰ组,而法氏囊指数稍高于试验Ⅰ组,说明发酵中草药微生态制剂可以抵抗大肠杆菌感染,脾脏和法氏囊发育不受影响;注射大肠杆菌后试验Ⅲ组大肠杆菌数量显著下降(P < 0.05),但试验Ⅲ组由于饲喂发酵中草药复合芽孢杆菌制剂,肠道乳杆菌数量显著增加,抑制大肠杆菌的繁殖,从而大肠杆菌数量与正常饲喂状态下的试验Ⅰ组趋于一致;42日龄时,盲肠内容物sIgA含量试验Ⅲ组分别高出试验Ⅰ、Ⅱ组11.99%和36.56%(P < 0.05),血清IgG含量试验Ⅲ组分别高出试验Ⅰ、Ⅱ组14.68%和28.15%(P < 0.05);42日龄时,试验Ⅱ组IL-2含量最低,显著低于试验Ⅲ组(P < 0.05),试验Ⅲ组IL-6含量显著低于试验Ⅱ组(P < 0.05)。  相似文献   
129.
5种药材在不同郁闭度油桐林下生长研究   总被引:1,自引:0,他引:1  
在不同郁闭度油桐林分套种玉竹、黄精、石蒜、桔梗和麦冬,测定不同药材在不同郁闭度油桐林分地上部分鲜重增量和地下部分鲜重生长情况。结果表明:油桐林分郁闭度在0.7以上的可套种玉竹、黄精等耐阴性药材,郁闭度在0.5~0.7可套种石蒜和麦冬等偏中性药材,在郁闭度小于0.3~0.5的可套种桔梗等喜光性药材。  相似文献   
130.
一种新型中草药复方制剂对母猪热应激的影响   总被引:1,自引:0,他引:1  
为了解一种新型中草药复方制剂对母猪热应激的影响,将45头空怀母猪随机分为常温对照组、高温对照组和试验组。常温对照组和高温对照组饲喂基础日粮,试验组在基础日粮中添加0.1%新型中草药复方制剂,连用10 d。结果表明,饲喂新型中草药复方制剂10 d后试验组母猪血清中热应激蛋白70(HSP70)含量显著低于高温对照组(P0.05),血液免疫球蛋白G(Ig G)、母猪发情率均显著高于高温对照组(P0.05)。本试验使用的新型中草药复方制剂能够明显改善母猪热应激下的不良状况。  相似文献   
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