2000～2013年三江平原北部NPP变化特征分析

应用最小二乘法和逐像元相关分析方法,结合三江平原土地利用变化数据,分析2000～2013年三江平原北部地区年均植被NPP变化情况,获得研究区NPP趋势变化数据及水田扩张与NPP空间相关数据.结果表明,三江平原北部在水田快速扩张驱动下,NPP值先缓慢减少后波动上升,整体为线性增加趋势.NPP具有明显年际增加趋势,基本规律为年均NPP值相对较低区域,增加趋势较弱,反之亦然.水田扩张与NPP值相关性分析表明,由旱地转为水田区域,水田扩张与NPP值变化具有正向相关性;由沼泽湿地和林地转为水田区域,水田扩张与NPP值变化具有负向相关性.研究表明,农田耕作方式是NPP变化重要影响因素之一.     

典型黑土垄作区耕地沟蚀对土壤养分的影响研究

近年来东北黑土区沟蚀吞食耕地现象加剧,养分流失、耕地质量下降等问题凸显。以宾县的糖坊镇和三宝乡为研究区,综合"3S"技术和统计学的模型方法,对研究区沟蚀对土壤中有机质、全氮、全磷和速效钾含量的影响及不同垄向耕作下沟蚀对各养分的影响及差异展开研究。其中横垄种植指作物垄的方向和地块坡向方向成垂直的种植方式,顺垄种植是作物垄的方向和地块坡向方向平行的种植方式。结果表明:沟蚀对土壤养分含量影响较大,有机质和全氮含量较无侵蚀区分别减少33.43%和46.67%,速效钾与全磷含量则变化不明显,在沟蚀区进行秸秆覆盖能够有效减少土壤养分的流失。沟蚀在造成养分含量下降的同时,也影响了土壤的理化结构,降低了土壤中有机质和全氮含量之间的相关性。横垄沟蚀、顺垄沟蚀及无沟蚀对照组土壤有机质和全氮含量大小均表现为无沟蚀区顺垄沟蚀橫垄沟蚀。无侵蚀区土壤养分含量最高,沟蚀区顺垄耕作较横垄耕作更具保肥意义。     

区域水—能源—粮食关联系统协同发展模型

[目的] 研究区域水—能源—粮食关联系统（WEFN）的协同发展状况,促进区域水、能源、粮食的可持续利用。[方法] 基于复杂适应系统理论,从水、能源、粮食3方面构建区域WEFN协同发展评价指标体系,以协同进化算法、灰色关联等为基础提出一种基于各要素条件和相互作用机理的综合协同发展模型,并以黑龙江省为例测算2009—2018年WEFN的协同发展度及子系统的发展度、协同度,评价其协同发展状况。[结果] ①各子系统发展程度中等,差距较小,协同度差距较大但均呈波动上升趋势,其中水资源对能源和粮食、能源对粮食的协同作用明显。②WEFN协调发展状况中等,与各子系统协同发展趋势一致,波动上升后保持稳定,粮食子系统协同发展程度最高。③子系统间协同作用差是造成WEFN协同发展状况不高的原因,应以水、能源在农业生产中的高效应用为突破口,促进子系统间的协同发展。[结论] 综合协同发展模型能够有效评价区域WEFN的协同发展状况,有助于区域可持续发展决策。     

Variations in soil infiltration capacity after vegetation restoration in the hilly and gully regions of the Loess Plateau,China

Purpose

To control the severe soil and water losses on the Loess Plateau, China, a series of vegetation restoration projects were conducted. A better understanding of the effect of vegetation types on the soil infiltration capacity is important for the sustainable development of vegetation restoration. The aim of this study was to establish a soil infiltration capacity index (SIC) and to analyze the mechanism influencing variations in the soil infiltration capacity after vegetation restoration on the Loess Plateau.

Materials and methods

Eight vegetation types (community dominated by Artemisia scoparia, Stipa bungeana, Artemisia gmelinii + S. bungeana, A. gmelinii + Stipa grandis, A. gmelinii + Artemisia giraldii, Sophora viciifolia, Caragana korshinskii, and Robinia pseudoacacia) and bare land as the control were selected for this study. The SIC was established by a steady infiltration rate (SR, 50–60 min) and stage I average infiltration rate (ARSI, 0–5 min) according to principal component analysis (PCA). Path analysis was used to investigate how the soil properties and plant fine root affected the soil infiltration capacity.

Results and discussion

The SIC values of the eight vegetation types were all higher than that of the bare land. The R. pseudoacacia community had the highest SIC value (0.43), followed by the A. scoparia community (0.30) while the bare land (??0.56) had the lowest value. Path analysis showed that the increase in the fractal dimension and non-capillary porosity of soil particles enhanced the SIC directly. Increases in the clay content increased the SIC by affecting the fractal dimension of soil particles, while increases in the fine root density reduced the SIC by affecting the non-capillary porosity. Plant functional groups (grasses and legumes) affected SIC indirectly via non-capillary porosity and plant root.

Conclusions

A comprehensive index, the SIC, was established to describe the soil infiltration capacity by the PCA method. Based on a comparison with bare land, vegetation restoration enhanced the soil infiltration capacity. The R. pseudoacacia community was the most effective at improving the soil infiltration capacity. The improvement in infiltration was closely related to direct increases in the soil non-capillary porosity and soil particle fractal dimension.

     

小米豆渣低糖纤维饼干工艺条件的优化

以面粉、小米粉、豆渣粉为主料,木糖醇为甜味剂制作小米豆渣低糖纤维饼干。以感官评价为指标,通过单因素试验确定各因素的最适条件,通过正交试验确定饼干的最佳配方为小米粉用量15 g,豆渣粉用量15 g,低筋面粉用量26 g,鸡蛋液用量22 g,木糖醇用量20 g,黄油用量22 g,擀压成5 mm厚的面坯后,于上层温度105℃,下层温度115℃的烤箱中烘烤10 min。此条件下可获得色泽焦黄、香味浓郁、口感松脆、硬度适中的小米豆渣饼干。     

通过对种母鸡的准确称重监测鸡群生产情况

在种母鸡的一生中,合适的取样和准确的称重是非常重要和必须的.通过称重来了解鸡群的体重和体况,让种鸡管理人员制定合理的饲喂程序,进而充分发挥种鸡遗传性能,获得最佳效益.     

Successional Trajectory Over 10 Years of Vegetation Restoration of Abandoned Slope Croplands in the Hill‐Gully Region of the Loess Plateau

Revegetation has been the primary management approach for solving the problems caused by severe soil erosion in the Loess Plateau. The objectives of this work were to explore the successional trajectory of the different types of restoration and discuss their potential effectiveness for the control of soil erosion. The presence and coverage of plants in 40 permanent plots were investigated during two periods (2003–2006 and 2013). The naturally and artificially revegetated communities studied in the two surveys were classified using two‐way indicator species analysis, and their relationships were analyzed using detrended correspondence analysis. Under natural revegetation, the communities succeed in the following order: annual plants → perennial plants → short rhizome tufts and subshrubs. Under artificial revegetation, succession was interrupted by artificial planting, and a Gramineae herb layer persisted through the years with few changes in species composition. Additionally, species richness, diversity, and evenness increased, while ecological dominance decreased during succession in both revegetation types. Succession rate was rapid at the initial stage and then slowed down gradually. Succession followed different trajectories under natural and artificial revegetation, and based on the potential effects of the two approaches on soil erosion and soil desiccation, we suggest that natural revegetation is preferable over artificial revegetation. Copyright © 2015 John Wiley & Sons, Ltd.