Subjects: Biology >> Botany >> Applied botany submitted time 2022-05-21 Cooperative journals: 《广西植物》
Abstract： To reveal the spatiotemporal variation characteristics of vegetation net primary productivity (NPP) in the Haihe River Basin and the driving mechanisms of its spatiotemporal heterogeneity. Based on MOD17A3HGF dataset, we studied the spatiotemporal pattern evolution characteristics of vegetation NPP in the Haihe River Basin from 2000 to 2020 using coefficient of variation, trend analysis, and Hurst index. Driving factors and their influence from natural and man-made aspects were also quantitatively explored for vegetation NPP variations using correlation analysis and the Geodetector model. The results were as follows: (1) The temporal variation of vegetation NPP in the Haihe River Basin presented a significant growth trend form 2000 to 2020, with a rate of 1.73 Tg C·a-1, and the annual average NPP was 326.75 g C·m-2·a-1; The average NPP of coniferous forests, broad-leaved forest, shrub, grassland and farmland were 313.59, 385.28, 353.03, 320.12 and 295.22 g C·m-2·a-1.(2) In terms of spatial distribution, the high-value areas of NPP were mainly located in the northwest mountains, and the low-value areas were mainly located in the southeast plain; The overall situation of NPP was relatively stable, with an average coefficient of variation of 0.17; The future trend of NPP is anti-continuity and it will decrease. (3) The correlation analysis showed that NPP was negatively correlated with temperature, and positively correlated with precipitation that was the main climate factor; NPP showed an “increase-decrease” trend with elevation and slope increasing; The conversion of farmland to grassland resulted in the largest increment of NPP at 732.22×10-3 Tg C. (4) From 2000 to 2020, the average influence value of different drivers was 0.2, and the order was precipitation > elevation > slope > humidity > temperature > sunshine duration > land use > wind speed. Overall, the results indicated that vegetation NPP in the Haihe River basin was improving during the study period; Productivity varied among different vegetation types, with the strongest being broad-leaf forest and shrubland; The dominant factors affecting the spatial distribution of NPP were precipitation, elevation and slope, and the influence of human factors was lower than that of natural factors. The results of above study can provide some scientific reference and decision basis for the treatment of ecological environment problems such as soil erosion and vegetation degradation in the Haihe River Basin.
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究植物精油混合物对海兰褐蛋鸡生产性能、蛋品质、卵泡发育及血清生殖激素指标的影响。选取432只体重和产蛋率接近的25周龄健康海兰褐蛋鸡，随机分为4组，每组6个重复，每个重复18只鸡。对照组饲喂玉米-豆粕型基础饲粮，试验组分别饲喂在基础饲粮中添加75、150和225 mg/kg植物精油混合物的试验饲粮。预试期3周，正试期12周。结果表明：1）150 mg/kg植物精油混合物组蛋重显著高于对照组(P0.05）。2）75和150 mg/kg植物精油混合物组哈氏单位显著高于225 mg/kg植物精油混合物组(P0.05）。3）各组间蛋鸡卵泡发育指标无显著差异（P>0.05）。4）225 mg/kg植物精油混合物组血清孕酮含量显著高于其他各组(P0.05）。综上所述，饲粮中添加150 mg/kg植物精油混合物可改善蛋鸡的蛋重及蛋白品质，且对卵泡发育的影响较小。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究植物精油混合物对海兰褐蛋鸡生产性能、蛋品质、卵泡发育及血清生殖激素指标的影响。选取432只体重和产蛋率接近的25周龄健康海兰褐蛋鸡，随机分为4组，每组6个重复，每个重复18只鸡。对照组饲喂玉米-豆粕型基础饲粮，试验组分别饲喂在基础饲粮中添加75、150和225 mg/kg植物精油混合物的试验饲粮。预试期3周，正试期12周。结果表明：1）150 mg/kg植物精油混合物组蛋重显著高于对照组(P0.05）。2）75和150 mg/kg植物精油混合物组哈氏单位显著高于225 mg/kg植物精油混合物组(P0.05）。3）各组间蛋鸡卵泡发育指标无显著差异（P>0.05）。4）225 mg/kg植物精油混合物组血清孕酮含量显著高于其他各组(P0.05）。综上所述，饲粮中添加150 mg/kg植物精油混合物可改善蛋鸡的蛋重及蛋白品质，且对卵泡发育的影响较小。
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