基于遥感生态指数的焦作市生态环境动态监测与评价

[目的] 探究河南省焦作市其近20 a来生态环境质量演化特征，可为该市及其他资源枯竭型城市生态建设提供科学参考。[方法] 选取2000，2006，2009，2014和2019年5期Landsat影像数据，耦合绿度、湿度、温度及干度4个指标，通过主成分分析法建立遥感生态指数（RSEI）评价模型，对焦作市生态环境质量进行定量评价。[结果] ①2000-2014年，焦作市生态环境质量为倒"U"形曲线，2014-2019年生态环境质量好转；②城镇人口占比增幅变缓及产业结构由第二产业向第三产业转变改善了焦作市生态环境质量；③回归分析中所选4个指标中对焦作市生态环境变化影响的重要程度表现为：干度 > 湿度 > 绿度 > 热度。[结论] 遥感生态指数对资源枯竭型城市生态环境质量可进行有效监测与评价。     

The influence of two agricultural biostimulants on nitrogen transformations, microbial activity, and plant growth in soil microcosms

The influence of two experimental soil treatments, Z93 and W91, on nitrogen transformations, microbial activity and plant growth was investigated in soil microcosms. These compounds are commercially marketed fermentation products (Agspectrum) that are sold to be added to field soils in small amounts to promote nitrogen and other nutrient uptake by crops in USA. In laboratory microcosm experiments, soils were amended with finely ground alfalfa-leaves or wheat straw, or left unamended, in an attempt to alter patterns of soil nitrogen mineralization and immobilization. Soils were treated in the microcosms with Z93 and W91 at rates equivalent to the recommended field application rates, that range from 0.2 to 1.1 l ha⁻¹, (0.005-0.03 μl g⁻¹ soil). We measured their effects on soil microbial activity (substrate-induced respiration (SIR), dehydrogenase activity (DHA) and acid phosphatase activity (PHOS)), soil nitrogen pools (microbial biomass N, mineral N, dissolved organic N), and transformations (net N mineralization and nitrification, ¹⁵N dilution of the mineral N pool, and accumulation of mineral N on ion-exchange resins), and on wheat plant germination and growth (shoot and root biomass, shoot length, N uptake and ¹⁵N enrichment of shoot tissues), for up to 56 days after treatment. To follow the movement of nitrogen from inorganic fertilizer into plant biomass we used a ¹⁵N isotopic tracer. Most of the soil and plant responses to treatment with Z93 or W91 differed according to the type of organic amendment that was used. Soil treatment with either Z93 or W91 influenced phosphatase activity strongly but did not have much effect on SIR or DHA. Both chemicals altered the rates of decomposition and mineralization of organic materials in the soil, which was evidenced by significant increases in the rates of the decomposition of buried wheat straw, and by the acceleration of net, rates of N mineralization, relative to those of the controls. Soil nitrate availability increased at the end of the experiment in response to both chemical treatments. In alfalfa-amended soils, the final plant biomass was decreased significantly by treatment with W91. Increased plant growth and N-use efficiency in straw-amended soil, resulting from treatments with Z93 or W91, was linked to increased rates of N mineralization from indigenous soil organic materials. This supports the marketing of these compounds as promoters of N uptake at these low dosage inputs.     

樱桃根际土壤酶活性与土壤养分动态变化及其关系研究

通过盆栽试验研究了樱桃根际脲酶、磷酸酶活性与氮、磷、钾动态变化及其相互关系。结果表明,生长季前期樱桃根际脲酶、磷酸酶活性明显提高,根际酶活性显著高于根外,随物候期进展土壤酶活性及R/S值逐渐降低。氮、磷、钾元素在年生长周期内整体上呈下降趋势,生长季前期根际全氮、碱解氮及全磷亏缺明显,而根际有效磷、速效钾明显富集,这种作用亦随物候期进展逐渐减弱。土壤脲酶、磷酸酶活性与氮磷钾土壤营养元素含量间存在着一定的相关性,以春梢停长期相关程度最高。     

DEHP对土壤脱氢酶活性及微生物功能多样性的影响

选用肥熟旱耕人为土(黄棕壤),设置了在土壤中施加100 mg kg-1 DEHP与不施加DEHP两个水平,盆栽试验研究了DEHP对土壤脱氢酶活性以及土壤微生物群落功能多样性的影响,以及植物在污染土壤中的修复作用。结果表明,施加DEHP显著抑制了土壤脱氢酶活性,30 d时与对照相比降低了约30%, 第60 d时尽管有缓慢的回升,但仍明显低于对照(p<0.05)。从BIOLOG反应的结果可以看出,DEHP也显著影响土壤微生物的功能多样性,土壤微生物群落的Shannon指数、Simpson指数、McIntosh指数和均度均显著低于无污染的对照,说明DEHP的污染导致了土壤微生物群落功能多样性的下降。种植植物对土壤脱氢酶和微生物活性有很明显的促进作用,并且在一定程度上缓解了DEHP的毒害作用,但并未消除DEHP对土壤微生物的影响。     

施肥对日光温室土壤微生物与酶活性变化的影响

在日光温室内,采用田间试验的方法,研究不同施肥处理对西红柿土壤酶活性和土壤微生物数量的影响。结果表明:施有机肥、化肥、有机肥 叶面肥处理土壤磷酸酶活性增加,施化肥 叶面肥处理比施化肥处理土壤磷酸酶活性增加;施有机肥处理土壤脲酶活性增强;施化肥 叶面肥处理土壤磷酸酶活性比施有机肥 叶面肥处理降低;施肥对蔗糖酶和过氧化氢酶活性的影响较小。施有机肥处理土壤细菌、真菌和放线菌数量增加,施化肥处理土壤细菌数量降低,土壤真菌和放线菌数量增加。     

黄瓜连作对土壤理化性状及生物活性的影响研究

盆栽与田间试验研究黄瓜连作对土壤理化性状及生物活性的影响结果表明,黄瓜连作后土壤次生盐渍化加重,P过剩,K则消耗过多,造成养分不平衡;土壤微生物区系改变,微生物由“细菌型”土壤向“真菌型”土壤转化,土传病虫害加重,线虫密度高达4.38条/g土。     

The effect of recreational disturbance on an upland breeding bird, the golden plover Pluvialis apricaria

The use of the countryside for recreation has increased dramatically in recent years. This has led to concern amongst conservationists about the effects increased human disturbance may have on important wild animal populations. In the UK, recent legislation has widened the level of access to upland habitats, which support internationally important breeding bird populations. Determining the extent to which recreational disturbance affects upland breeding birds is therefore a conservation priority. We used data collected over 13 years to investigate the impact of recreational disturbance on the distribution and reproductive performance of golden plovers breeding in close proximity to the Pennine Way, an intensively used long-distance footpath. Importantly, the Pennine Way was resurfaced in 1994 to prevent further erosion of the surrounding vegetation. We were therefore able to examine if the response of golden plovers to recreational disturbance was influenced by changes in the intensity and extent of human activity resulting from the resurfacing work. Before the Pennine Way was resurfaced, golden plovers avoided areas within 200 m of the footpath during the chick-rearing period. At this time over 30% of people strayed from the footpath and the movement of people across the moorland was therefore widespread and unpredictable. Following resurfacing, over 96% of walkers remained on the Pennine Way, which significantly reduced the impact of recreational disturbance on golden plover distribution; golden plovers only avoided areas within 50 m of the footpath at this time. Despite the clear behavioural responses of golden plovers to the presence of visitors, there was no detectable impact of disturbance on reproductive performance. In many countries, a conflict arises between the use of the countryside for recreational purposes and the protection of habitats or species of high conservation value. However, this study suggests that the implementation of simple measures to influence visitor behaviour can dramatically reduce the impact of recreational disturbance on wild animal populations.     

Microbial activity and bacterial composition of H2-treated soils with net CO2 fixation

The effects of H₂ gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO₂ dynamics and microbial activity and composition were analyzed. The H₂ emission rate of 250 nmol H₂ g⁻¹ soil h⁻¹ was similar to the upper limit of estimated H₂ amounts emitted from N₂ fixing nodules into the surrounding soil ([Dong, Z., Layzell, D.B., 2001. H₂ oxidation, O₂ uptake and CO₂ fixation in hydrogen treated soil. Plant and Soil 229, 1-12.]). After 1 week of H₂ supply to soil samples simultaneously with H₂ uptake net CO₂ production declined continuously and this finally led to a net CO₂ fixation rate in the H₂-treated soil of 8 nmol CO₂ g⁻¹ soil h⁻¹. The time course of H₂ uptake and CO₂ fixation in the soils corresponded with an increase in microbial activity and biomass of the H₂-treated soil determined by microcalorimetric measurements, fluorescence in situ hybridization analysis (FISH) and DNA staining (DAPI). Shifts in the bacterial community structure caused by the supply of H₂ were recorded. While the H₂ treatment stimulated β-and γ-subclasses of Proteobacteria, it had no significant effect on α-Proteobacteria. In addition, FISH-detectable bacteria of the Cytophaga-Flavobacterium-Bacteroides phylum increased in numbers.     

Biochemical diversity in the genus Coffea L.: chlorogenic acids,caffeine and mozambioside contents

Summary The extent and nature of biochemical diversity in green coffee beans was established by a large sampling of genus Coffea, representing nine species from the Guineo-Congolian region, nine species from east Africa and seven species from Madagascar. HPLC analyses were used to determine the contents of caffeine, chlorogenic acids and mozambioside. Data processed by principal component analyses showed the existence of two metabolic pathways. One leads to the synthesis of small quantities of chlorogenic acids (< 2.5% dmb) and caffeine ( < 0.3 % dmb) while the other leads to large concentrations of chlorogenic acids (> 4.5% dmb) and caffeine (> 0.4% dmb). Their distribution in the genus Coffea is discussed in relation to the biogeographic origin of the plant material.     

植茶年龄对茶园土壤微生物特性及酶活性的影响

分析了浙江省两个典型茶区土壤化学、微生物学性质以及酶活性。结果表明,茶园土壤的酸化程度随植茶年龄的增加而加重,土壤有效态N以NO-3 N为主。两茶区高龄茶园的土壤微生物量均很低,表明长期植茶形成的独特生态环境对微生物有抑制作用。两茶园土壤微生物代谢商(Rmic/Cmic)都较非茶园对照土壤低,并且随植茶年龄的增加,两者呈相似的变化趋势。土壤微生物商的变化可能与茶园土壤环境胁迫状况有关,低龄茶园的土壤微生物商(Cmic/Corg)高于非茶园对照土壤,也明显高于高龄茶园。土壤有机碳,全N ,有效P ,NH-4 N ,NO-3 N ,脲酶和酸性磷酸酶活性均随植茶年龄的增加而增加,而与土壤pH值呈相反的变化趋势