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以虾头蟹壳废弃物为有机土壤改良剂、以凹凸棒为无机土壤改良剂,采用小麦-玉米轮作方式,在河北砂质潮土进行4年（2015—2019年）田间定位试验。试验设4个处理：无改良剂（CK）、无机改良剂（SA）、有机改良剂（SC）、无机改良剂+有机改良剂（SCA）。采集2019年玉米收获后的耕层土壤,测定土壤化学性质、氮循环功能基因丰度、胞外酶活性等,并用因子分析法和内梅罗指数法计算土壤综合肥力指数（IFI）。结果表明,（1）改良剂能够显著提升土壤固氮基因（nifH）、氨氧化细菌基因（AOB-amoA）、反硝化基因（nirS和nosZ）的绝对丰度（P<0.05）,且呈现SCA>SC>SA。有机碳是影响土壤氮循环功能基因丰度的关键因子。（2）施入有机改良剂后,参与碳转化的β-葡萄糖苷酶和β-纤维二糖苷酶、氮转化的β-1,4-N-乙酰氨基葡萄糖苷酶和亮氨酸氨基肽酶、磷转化的碱性磷酸酶活性均显著增加（P<0.05）。有机改良剂的添加缓解了磷对微生物的限制,有效磷成为影响胞外酶活性的关键因子。（3）在涵盖氮循环功能基因和胞外酶活性条件下,用因子分析法计算得到的IFI与产量的相关性更高... 相似文献
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【Objective】 Soil fauna is an important component of terrestrial ecosystem, therefore, the studying of the relationship between soil fauna and amendments will help reveal the mechanism of amendments to soil fauna.【Method】During 2016-2019, the characteristics of the soil fauna community in the soil surface layer (0-20 cm) of wheat and maize rotation area with different amendments were investigated. There were four treatments, including no amendment (CK), organic amendment 15 t·hm-2 (YJ), inorganic amendment 2.25 t·hm-2 (WJ) and organic amendment 15 t·hm-2+inorganic amendment 2.25 t·hm-2 (YW). 【Result】During the study period, 4 351 soil fauna belonging to 8 classes, 20 orders, 41 families, and 44 classes were collected, of which 28 families were macrofauna, and the dominant groups were Asilidae and Myrmicinae, accounting for 62.9% of the total captured soil macrofauna. In another, 14 families soil meso-and micro-fauna were collected, and the dominant groups were Acarid and Oribatida, accounting for 93.0% of the total captured soil meso- and micro-fauna. Soil fauna mainly belonged to saprozoic and omnivores. The data indicated that the total number and taxa of soil fauna collected during the experiment was the highest under WJ, and the lowest under YJ. The number of Scutigerellidae, Sejidae and Japygidae decreased and their richness index decreased, while the mites increased, and the dominance index was high under amendments comparing with CK. There were significant differences in individual number and diversity index of small and medium animal communities among different years (P<0.05), and the number of individuals showed a gradually increasing trend; but the Jaccard index (q) of soil fauna was less than 0.50 among all treatments, and the similarity of macrofauna community was lower than that of meso- and micro- community. The ecological niche widths of meso- and micro- soil fauna, such as Acarid, Oribatida, and Onychiuridae, were higher than those of macrofauna, such as Myrmicinae. However, the niche overlap index was higher than 0.97, indicating that the application of amendments increased the common resources of soil fauna. The NMDS analysis showed that the soil animal community in wheat season 2018 was significantly different from that in other years, whereas, in maize season of 2016, 2018, and 2019, there were different. The results of RDA indicated that soil TN and AK were significantly correlated with Acarid, Oribatida, Onychiuridae, Enicocephalidae, Carabidaein wheat season (P<0.05); the soil organic matter and pH were main factors influencing Acarid, Enicocephalidae, Sciaridae, and Asilidae in maize season (P<0.05). The PRC analysis showed that the relative abundance of Uropodidae peaked in October 2017, and that of Asilidae and Myrmicinae peaked in October 2016 under YJ. The relative abundance of Onychiuridae, Acarid, and Oribatida reached a peak in October 2016 under the combined application of organic and inorganic amendments, and that of Phlaeothripidae and Enicocephalidae appeared in 2019 and peaked in October 2019, demonstrating the incongruity of soil fauna groups to the amendments. 【Conclusion】The variation of soil fauna community and diversity in different years were much more profound than amendments, and the amendments modified soil fauna community and diversity mainly by changing soil pH, SOM, and TN in a fluvo-aquic sandy soil. 相似文献
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广东省惠州市建成区拥有丰富的湿地资源,同时位于全球候鸟"东亚—澳大利亚"迁徒路线上中端位置,在全球候鸟保护上具有重要意义.然而,快速城市化发展加剧了湿地鸟类栖息地的破碎与萎缩,威胁着湿地鸟类多样性的可持续发展.为进一步加强建成区湿地鸟类多样性保护,在建成区湿地鸟类资源全面调查的基础上,利用GAP分析方法对湿地鸟类丰富度的空间分布格局与热点区域进行了研究.结果 如下:(1)共调查记录到鸟类14目42科136种,有珍稀濒危物种12种;(2)建成区的北部和西部是鸟类丰富度最高区域,同时也是保护热点区域,在鸟类多样性保护具有重要地位.建议将尚未纳入自然保护地内鸟类丰富度高的热点区域纳入自然保护地体系,同时在北部和西部之间建立生态廊道,以实现对鸟类的有效保护. 相似文献
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本研究的目的是确定在一个由土著燕鸥占据的繁殖岛上，进入一种新的燕鸥定居，由此产生的种间竞争是否会改变它们的资源利用模式、巢址选择偏好和繁殖生态等。为此，我们于2019年，研究了乌屿岛粉红燕鸥，褐翅燕鸥和大凤头燕鸥的巢址选择偏好和繁殖生态，并在已有的研究基础上，探讨了新的种间竞争如何影响到它们巢址选择和繁殖生态。结果显示：（1）大凤头燕鸥占据了粉红燕鸥的巢址，迫使粉红燕鸥侵占褐翅燕鸥的巢区，出现粉红燕鸥和褐翅燕鸥最佳巢址重叠的现象；（2）在大凤头燕鸥的竞争压力下，褐翅燕鸥倾向于低密度的繁殖方式，而粉红燕鸥则偏向于高密度的繁殖方式；（3）大凤头燕鸥进入后，粉红燕鸥平均窝卵数由1.17±0.07增加到1.76±0.43，有2枚卵的巢占比由1/6增加到3/4。 相似文献
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