979 resultados para Seasons.
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Total air suspended particles (PM 100) collected from an urban location near a traffic line in Wuhan, China, were examined for estrogen using a recombinant yeast bioassay. Wuhan, located at the central part of China, is the fourth biggest city in China with 7 million populations. Today, Wuhan has developed into the biggest city and the largest traveling center of central China, becoming one of the important bases of industry, education and research. Wuhan is right at the confluent point of Yangzi River, the third longest river in the world, and its largest distributary Hanjiang, with mountains and more than 100 takes in downtown area. Therefore, by its unique landscape, Wuhan has formed clear four seasons with relatively long winter and summer and short spring and autumn. Foggy weather usually happen in early spring. The yeast line used in this assay stably expresses human estrogen receptor-alpha. Weak but clear estrogenic activities were detected in the organic phase of crude extracts of air particle materials (APM) in both sunny and foggy weather by 0.19-0.79 mug E2/gPM(100) which were statistically significantly elevated relative to the blank control responding from 20% to 50% of the maximum E2 response, and the estrogenic activity was much higher in foggy weather than in sunny weather. The estrogenic activities in the sub-fractions from chromatographic separation of APM sampled in foggy days were also determined. The results indicated that the responses of the fractions were obviously higher than the crude extracts. Since there is no other large pollution source nearby, the estrogenic material was most likely from vehicle emissions, house heating sources and oil fumes of house cooking. The GC/MS analysis of the PM100 collected under foggy weather showed that there were many phenol derivatives, oxy-PAHs and resin acids which have been reported as environmental estrogens. These results of the analysis of estrogenic potency in sunny and foggy weather in a subtropical city of China indicate that further studies are required to investigate the actual risks for the associated health and atmospheric system. (C) 2004 Elsevier Ltd. All rights reserved.
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The reproductive traits of Gymnocypris selincuoensis from Selincuo Lake and its tributaries were investigated in 1997 and 1998. The youngest mature male was age 7 with a standard length (SL) of 172.0 mm, and the youngest mature female was age 8 with a SL of 194.0 mm. The L(50)s Of SL and age at first maturity were respectively 250.32 mm and age 9 for males and 224.71 mm and age 8 for females. The gonadosomatic index (GSI) significantly changed with seasons for mature individuals but not for immature individuals. GSIs of mature females at stages IV and V of ovary development increased with SL and reached a maximum value at the SL range from 370 mm to 390 mm; the GSIs of mature males were negatively correlated with SL. The breeding season lasted from early April to early August. Egg size did not significantly change with SL but increased with the delay of spawning. The individual absolute fecundity varied from 1,341 to 28,002 eggs (mean 12,607+/-7,349), and the individual relative fecundity varied from 6.4 to 42.0 eggs.g(-1) (mean 25.5+/-9.7). The individual fecundity increased with total body weight; it also increased with SL for those of SL less than 370 mm. There was a rest of spawning for mature individuals.
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Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus, and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for I-I. swinhonis and C. giurinus, and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis, high in winter and low in spring and summer for C. giurinus, and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn. (C) 2000 The Fisheries Society of the British Isles.
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The spatial pattern of the small fish community was studied seasonally in 1996 in the Biandantang Lake. Based on plant cover, the lake was divided into five habitats, arranged in the order by plant structure complexity from complex to simple: Vallisneria spiralis habitat (V habitat), Vallisneria spiralis-Myriophyllum spicatum habitat (V-M habitat), Myriophyllum spicatum habitat (M habitat), Nelunbo nucefera habitat (N habitat), and no vegetation habitat (NV habitat). A modified popnet was used for quantitative sampling of small fishes. A total of 16 fish species were collected; Hypseleotris swinhonis, Ctenogobius giurinus, Pseudorasbora parva, Carassius auratus and Paracheilognathus imberis were the five numerically dominant species. In both summer and autumn, the total density of small fishes was about 10 ind m(-2). Generally, Ctenogobius giurinus, a sedatory, benthic fish, was distributed more or less evenly among the five habitats, while the other four species had lower densities in the N habitat and NV habitat, which had the simplest structures. The distribution of the small fish species showed seasonal variations. In winter, most species concentrated in the V habitat, which had the most complex structure. In spring, the fish had low densities in the N and NV habitat, and were more or less evenly distributed in the other habitats. In summer, the fish had a low density in the NV habitat, and were evenly distributed in the other habitats. In autumn, the fish had higher densities in the V-M and M habitats than in the others. Generally, spatial overlaps between the dominant species were higher in winter than in the other seasons. It was suggested that the variations in the importance of predation risk and resource competition in habitat choice determined the seasonal changes of spatial patterns in the small fishes in the Biandantang Lake.
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Nutrient addition bioassays were conducted in 10 L carboys with water from a eutrophic farm pond. The four bioassay treatments each conducted in triplicate were control (no nutrients added), +N (160 mu mol L(-1) NH4Cl), +P (10 mu mol L(-1) KH2PO4), and N+P (160 mu mol L(-1) NH4Cl and 10 mu mol L(-1) KH2PO4). The size fractionated (0.2-0.8, 0.8-3, > 3 mu m) contents of the carboys were analyzed after 7 d for alkaline phosphatase activity (APA) and chlorophyll-a content. Chlorophyll data suggested P deficiency in ammonium and control mesocosms and no P deficiency with phosphate additions. Pond water also was collected in June, August, October, and March for measurement of APA. In water from the pond, the greatest V-max of APA usually was associated with microorganisms in the size classes between 0.8-3 mu m. In mesocosm experiments, the N+P treatment increased V-max of dissolved and particulate associated APA in the 0.2-0.8 mu m size range and in dissolved form. The V-max of APA in the largest size-fraction (> 3 mu m) increased markedly with P deficiency (+N treatment) and decreased in the P-enrichment treatment. The patterns of APA and chlorophyll associated with different size fractions often varied independently among different treatments and seasons and not always as a function of P deficiency, indicating the difficulty of attempting to normalize APA to phytoplankton biomass or chlorophyll. The Michaelis half saturation constant of APA in the pond water showed no strong trends with varied seasons or size fraction.
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Studies on mixed mass cultivation of Anabaena spp. on a large scale (5170 m2) were conducted continuously for 3 years. Under the continental monsoon climate in northern subtropics (30-degrees-N, 115-degrees-E), 7-11 g dry weight m-2 day-1 of microalgal biomass on average was harvested in simple plastic greenhouses in the effective growth days during the warmer seasons. The maximum productivity was 22 g m-2 day-1 in the middle of summer. Observations on the productive properties of strains of Anabaena spp. indicated that they were different from and could compensate for each other in their productivities and adaptations to the seasonal changes. With different lining materials (PVC sheets, concrete, sand and soil) in the culture ponds, no significant variation of productivity was found, but bubbling with biogas in the middle of the day and the application of some growth regulating substances (2,4-D, NaHSO3 and extracts of oyster mushroom spawn) was able to improve the production. The cost of microalgal biomass in this way was around 0.75-1.0 US dollar(s) per kilogram.
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采用野外样线取样与室内萌发相结合的方法研究了黄土高原丘陵沟壑区退耕地种子库的组成、密度、分布特征、季节动态、种子库类型。结果表明,土壤种子库中共发现50种植物的种子,隶属15个科,39个属,主要物种组成与密度季节间差异不显著;在演替过程中土壤种子库的物种数量与密度随退耕年限的增加表现出:增加-减少-增加的趋势,同时阳坡种子库密度波动较阴坡剧烈;土壤种子库密度年内变化范围为1 067~14 717粒/m2,土壤种子库平均密度是夏季>秋季>春季;研究区域退耕地土壤种子库类型属于以猪毛蒿为优势种,并具有其他一年生、多年生草本植物与灌丛种子的没有显著的季节动态的持久种子库,是物种适应黄土丘陵沟壑区特有生态环境条件的繁殖更新策略;从土壤种子库的物种组成、密度、类型来看,黄土丘陵沟壑区退耕地具有一定的自然恢复潜力。
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试验研究了在延安日光温室不同前茬作物条件下,黄瓜随着生长季节的变化其产量和品质及土壤呼吸和酶活性的动态变化。结果表明,前茬为豇豆的黄瓜产量和土壤碱性磷酸酶活性较高,前茬为番茄的黄瓜可溶性糖含量和土壤呼吸强度较高,前茬为四季豆的黄瓜维生素C含量较高,前茬为翻青玉米的黄瓜硝酸盐含量和土壤脲酶活性较高,前茬为翻青黑豆的土壤蔗糖酶活性较高。从提高黄瓜产量的角度出发,豇豆-黄瓜是最佳模式,而从改善黄瓜品质的角度出发,番茄-黄瓜和四季豆-黄瓜是最优模式
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本学位论文首先报道了为解决低极性化合物的电喷雾质谱(ESI-MS)分析难题而建立的一种衍生化分析方法;然后从色谱-质谱联用分析、分离纯化和结构鉴定等方面分别报道了几种中藏药材的活性成分研究。论文由下述六章组成: 第一章报道了盐酸羟胺衍生化方法在电喷雾质谱 (ESI-MS) 分析中的应用。该方法利用盐酸羟胺和羰基成肟的快速反应,建立了针对三萜酮等含酮或醛羰基低极性化合物的ESI-MS 信号增强技术。此方法不仅可应用于增强羰基化合物的ESI-MS 质谱信号,还可检测化合物中羰基的个数以及辨别涉及羰基官能团的同分异构体。此外,通过简单的氧化反应,还可将该方法拓展到三萜醇、甾醇等含羟基的低极性化合物,增强它们的ESI-MS 信号。对比已报道的相关ESI-MS 增强质谱信号的衍生化方法,此方法有经济、实用、快速和简便的显著特点。 第二章是关于野生羌活及其栽培品种化学成分的色谱-质谱联用分析。对不同产地野生羌活生长过程中活性成分的动态变化、野生羌活不同形态部位和人工栽培羌活中的活性成分含量进行了HPLC 定量分析。结果表明主要活性成分羌活醇和异欧前胡素都随生长期存在规律性变化,羌活不同形态部位中的活性成分含量也有明显不同。这些实验结果有些较好地印证了传统中医的用药理论,有些也对羌活的传统使用方法提出了新的建议。 第三章介绍了几种传统中藏药材的色谱-质谱联用及串联质谱分析。通过GC-MS 方法,从藏药材长花党参挥发油中共分离鉴定出45 个化合物;利用HPLC方法测定了该藏药材中的主要化学成分——木犀草素的含量(0.7%);利用串联质谱技术,对西番莲和射干中的主要成分进行了快速鉴定,从西番莲中鉴定了4个黄酮碳苷;从不同产地的射干和川射干中鉴定了8 个主要异黄酮成分,其中包括一个未见报道的化合物。 第四章的内容为藏药材石莲叶点地梅的活性成分研究。从植物石莲叶点地梅(Androsace integra (Maxim.) Hand.-Mazz.) 乙醇提取物的正丁醇萃取部分共分离和鉴定了6 个化合物,利用MS 和NMR 等现代波谱学技术阐明了它们的结构:其中包括4 个三萜类化合物:分别是androsacin (1)、 ardisiacrispin A (2) 、saxifragifolin A (3) 和20(29)-lupen-3-one (4);一个神经酰胺:4-羟基-Δ8,9(Z)-鞘氨醇-2'-羟基正二十四碳酸酰胺(5);一个甾体类化合物:胡萝卜苷(6)。化合物1为新的13,28-epoxy-oleanane 型三萜皂苷,在其结构表征的过程中,采用LC-MS 进行糖分析,获得了值得推广的好结果。通过活性筛选发现化合物1~3 对HepG2肝癌细胞表现出不同程度的抑制活性,其中化合物2 活性最好,其IG50 为1.65μg/mL。 第五章是关于一些传统中藏药材的农药活性筛选。利用Syngenta 公司的活性筛选平台对68 种传统中藏药材醇提物进行了抗菌和除草的生物源农药活性筛选。结果表明所筛选的68 种植物提取物中,共有14 种样品表现出明显的除草/杀虫活性,其中水母雪莲花、松萝和茯神木等植物提取物还具有多种生物活性。活性成分还有待进一步追踪分离、纯化和结构鉴定。 第六章为文献综述,概述了羌活药材的研究进展。对羌活属及药用羌活植物从分类学、本草学、品质评价、人工栽培、化学成分及药理作用等方面进行了文献归纳和总结。 In this dissertation, an electrospray ionization mass spectrometry (ESI-MS) signal enhancement method, as well as the work of bioactive components study, HPLC-MS/MS application, bioassay screening, chromatograph separation and structure identification of the metabolites in several medicinal herbs have been reported. First chapter expounded a rapid, simple ESI-MS sensitivity enhancement method for detecting carbonyl groups in natural products has been developed by using hydroxylamine hydrochloride (NH2OH·HCl) as a derivatization reagent. We use the oxime formed during the derivatization reactions and its Beckmann rearrangement intermediates as a means of detecting the carbonyl groups originally present in these triterpenoids. In comparison with other derivatization methods in the literature, this method is simple, specific and can be used to detect carbonyl groups in triterpenoids which have low polarity and are poorly or non-ionizable. Moreover, it can also be used to detect hydroxyl groups by using the Dess-Martin periodinane (DMP) to convert primary and secondary hydroxyls into carbonyl groups. Chapter 2 reported an HPLC-MS method for analyzing the main bioactive compounds in both wild and cultured Notopterygium incisum. The results indicated that the main bioactive compounds varied through different seasons regularly, and in different commercial parts of this herb the content of these compounds also differed from each other. The quantitative analysis results showed that in the traditional commercial parts, the content of main chemical constitutes in Silkworm Notopterygium, Bamboo Notopterygium and Irregular-nodal Notopterygium are higher than that in Striped Notopterygium. This result is tally with the traditionally concept that the quality of Notopterygium, Bamboo Notopterygium and Irregular-nodal Notopterygium are better than that of Striped Notopterygium, which means that the quality of rhizomes is better than main roots. The chemical constituents of cultured N. incisum is reported for the first time in this dissertation and the analysis results showed some growth curves of chemical constituents in this plant, but still left some questions unanswered. Chapter 3 discussed the GC/LC-MS analysis of the traditional Chinese medicines Codonopsis thalictrifolis, Passiflora incarnate, Belamcanda chinensis and Passiflora incarnate. The main constituent, luteolin was isolated and identified from the traditional Tibet medicine of C. thalictrifolis. The quantitative analysis by HPLC has revealed that the content of luteolin in this herb is 0.7%. GC-MS was employed to analyzed chemical constituents of the essential oil from the flower of C. thalictrifolis. More than 60 peaks were detected and 45 of them were identified by comparing their spectra with that of the standards in the database and literatures. ESI-MS/MS was used to analyze the n-butanol extract of Passiflora incarnate. Based on the information of pseudo molecular ions and fragment ions of the glycosides, four major flavone-C-glycosides have been detected and identified as 7-methoxyluteolin-6-C-β-D-glucopyranoside, vitexin, swertisin and orientin. The isoflavone compounds in theextracts of three samples of B. chinensis collected in Gansu, Sichuan and Hunan, and the extract of Iris tectorum collected in Sichuan were analyzed by using TOF-HRMS and IT-MS. From the extracts of these herbs, a new isoflavone, identified as 5’,5,6,7-tetrahydroxy-3’4’-dimethoxyl isoflavon, and 7 known ones have been identified by analyzing the fragmentation patterns and their molecular formulas given by HRMS and the tandem mass spectrometry acquired by IT-MS. Chapter 4 elucidated the isolation and identification of a new triterpene saponin, androsacin (1), along with five known compounds (2-6) were isolated from the whole plants of Androsace integra (Maxim.) Hand.-Mazz., an herb used in traditional Chinese and Tibetan medicine. The chemical structure of the new compound was established as 3β-O-{β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-[O-β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl}-16α-hydroxy-13β,28-epoxy-olean-30-al by analyzing its MS, 1D- and 2D-NMR spectra. Compound 2 was cytotoxic toward HepG2 cancer cell with the GI50 value of 1.65 μg/mL. Chapter 5 described the biogenic pesticide activity screening of 68 traditional Chinese and Tibetan medicine extractions. The intention of this study is to explore bioactive natural compounds from these traditional medicinal herbs for biogenic insecticides use. Based on Syngenta’s bioassay, 14 extractions of these traditional medicines showed pesticide activities, and some of them had multi-activities on antibacterial and insecticidal. Chapter 6 is a review on the chemical and bioactivity research progress of Notopterygium incisum and N. forbesii.
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土壤线虫是土壤动物的主要功能类群之一,在土壤养分分解和循环中起到重要的作用。本研究通过施用两种形态氮肥,硝态氮(NO-3–N)和铵态氮(NH+4–N),对黄瓜整个生长期内根际土壤线虫的群落组成、结构及其多样性等的影响进行了比较研究。为增进土壤健康,提高土壤质量以及合理施用氮肥提供科学的理论依据。研究结果如下: 1. 氮肥处理后,不同浓度NO-3–N处理提高了根际土壤线虫数量,而NH+4–N处理(202.5 kg N/ hm2)抑制了线虫数量的增加。线虫群落结构相对较稳定,营养类群变化不大。且少量优势科/属会对土壤线虫群落特征起着至关重要的作用。 2. 在整个生长季节内,非寄生线虫的群体动态变化与寄生线虫的群体的动态变化具有相反的变化趋势。其中,NO-3–N处理和NH+4–N处理后植物寄生线虫出现频率的变化趋势相近,都是由高到低;非植物寄生线虫出现频率的变化趋势则都是由低到高。这说明非植物寄生线虫数量增长和空间占位对植物寄生线虫群体有一定的抑制作用。另外,也反映了适量氮肥在一定程度上能够减轻植物寄生线虫对黄瓜的危害。 3. 由多样性指数变化可知,NO-3–N和NH+4–N在低肥(67.5 kg N/hm2)和高肥(202.5 kg N/hm2)处理较中肥(135.0 kg N/hm2)处理,更不利于提高土壤线虫多样性地提高和线虫群落的稳定性。中肥不同形态氮肥处理与对照相比,H´指数在初花期和结果期显著增加了土壤线虫的H´指数,说明施入两种形态的氮肥能够提高线虫生物多样性程度。NH+4–N处理在初花期和结果期显著降低了土壤线虫种类的丰富性。土壤线虫生物多样性变化中,H´和SR指数在一定程度上能够反映施用无机氮肥对土壤线虫的多样性的影响,而J指数和λ指数效果不明显。NO-3–N和NH+4–N处理相比较,NO-3–N处理对黄瓜土壤线虫的多样性指数影响更大,促进了土壤线虫群体的多样化和种类的丰富度,更有利于提高土壤线虫的多样性,增加其稳定性。这些结果表明适量无机氮肥特别是NO-3–N的施用对黄瓜土壤线虫的生物多样性有一定的维护和提高作用。 4. 线虫数量与土壤质量指标的相关分析表明:线虫数量与有关土壤理化生指标,如土壤NO-3–N、NH+4–N、有机质含量等的正相关程度高,与总酚含量等显著负相关;与根际土壤微生物,细菌、真菌、放线菌数量等呈显著正相关。另外,线虫数量与土壤含水量未表现出显著相关关系。 Nematodes play a major role in decomposition and nutrient cycling in soil. Nematode community analyses are useful in assessing soil ecosystem status and function. The effects of two forms of mineral nitrogenous fertilizers (NO-3–N and NH+4–N) on nematode community composition, structure and diversity in rhizosphere of cucumber were investigated during different growing seasons of cucumber. Systematically research of effects of nitrogenous fertilizers could help to obtain better undstanding of a healthy soil and using nitrogenous fertilizers in reason. The main results are as follows: 1. The total numbers of nematode were more abundant in NH+4–N treatments than other teatments. However, NH+4–N teatment(202.5 kg N/hm2)dramatically inhibited it. All the tropic groups in the soil nematode communities were stable, and the dominant family or genus had an important function in the nematode community structure. 2. There was similar trend of the frequency of plant parasitic nematodes between NO-3–N and NH+4–N treatment, the similar trend of the frequency of non-plant parasitic nematodes was also found. But the frequency of plant parasitic nematodes exhibited a contrary trend to that of plant parasitic nematodes after different nitrogenous fertilizer treatments. The results showed that the increasing trend of the frequency and the niche of non-plant parasitic nematodes inhibited the plant parasitic nematodes, and indicated that right chemical fertilizers dosage could abate plant parasitic nematodes harm to cucumber. 3. The changes of the biodiversity index showed that the nitrogen treatment(135.0 kg N/hm2)promoted the stabilization of soil nematode diversity than other nitrogen treatments(67.5 kg N/hm2 and 202.5 kg N/hm2). In the treatment(135.0 kg N/hm2),The changes in nematode diversity between the control plots and treated plots were compared by the biodiversity index (H´, J, SR, λ). Among these tested index, H´ and SR were effective in reflecting the effects of different nitrogenous fertilizers on the diversity of soil nematodes. In comparison with the NH+4–N treatment, the NO-3–N treatment promoted the stabilization of soil nematode diversity. 4. Correlation coefficients between nematode abundance and soil quality indices indicated that the total numbers of nematode were affected positively by NO-3–N, NH+4–N and the organic matter, and negatively by total phenolic acids; the total num- bers of nematode had positive correlation with bacteria, fungi and actinomycetes nu- mbers. Soil water contents had only a weak negative influence on it.
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混农季节性放牧(agropastoral transhumance)通过作物种植和畜牧生产相结合的方式对不同海拔高度带上的资源进行相互补充利用,在亚洲兴都库什地区、青藏高原、横断山、东部及南部非洲、南美安第斯地区等具有悠久的历史。这种传统的生计系统几千年以来一直是居住在该地区的人类社会和自然生态系统相互作用的主要形式之一。这种传统的资源利用方式与山地自然植被以及特殊的山地人类文化和社会特征具有密切的协同演变关系。认识和理解这一关系,是山地生态学和人类学的核心科学问题之一。近年来,山地生态系统的多重功能性及动态演变对山区社会经济可持续发展的重要意义受到人们的不断关注。本文通过对云南省德钦县的12个自然村的混农季节性放牧以及对云南德钦、四川壤塘等山地植被格局特别是高海拔地带植被格局的的详细调查,探讨青藏高原东缘地区混农季节性放牧的主要特征、系统构成及相互关系,及其在全球变化、经济全球化和市场化及现代化过程中的变化趋势,分析混农季节性放牧与高山林线格局及生态系统的互动关系,旨在探讨山地地区人类活动与自然生态系统之间的互动关系,从而为山区社会经济可持续发展、环境建设和生物多样性保护等国家战略提供理论依据。 调查结果表明,混农季节性放牧是一种适应青藏高原东部高山峡谷地区环境因子及自然资源呈明显的垂直分布、资源数量稀少而时空分布异质性极高的生存环境的一种传统经济形式。这种传统的畜牧业的主要生产目的仍然是提供当地基本生存所需的产品,饲养牲口的种类和数量取决于农户的当地需求并且受资源的限制,因而维持在比较低的水平的。分布在不同海拔高度的放牧资源在一年中被牲口利用的时间也不同,互为补充,共同构成混农季节性放牧的资源基础。根据各社区永久居住点的位置和该村的土地资源特别是牧草地资源的分布范围,牲口迁移的距离和格局有较大的差异。。天然牧场仍然是最主要的畜牧业生产资源。混农季节性放牧中的农业系统和牧业系统互为补充,共同构成调查地区完整的的生计系统,农耕活动为放牧活动提供精饲料如粮食等和冬季饲料如秸秆, 其数量往往成为家庭畜牧业生产规模的主要决定因子之一。 通过对牲口数量和结构、牲口的时空迁移格局、牧业活动在整个经济活动中的相对重要性以及牧业活动和作物种植的关系方面的研究分析,混农季节性放牧在近几十年发生了深刻的变化。主要表现在牲口数量总体下降,牲口组成发生变化,牲口移动性降低、牧业活动的经济重要性下降以及牧业活动和种植活动之间的相互依存度降低等。上述变化的根本驱动力是发生在当地、地区及全球尺度上的环境、政治、社会经济、技术和文化等的变化,从而造成当地群众畜牧生产目标、土地利用和劳动力的分布等发生了变化。当地生计系统发生的改变可能会带来对方面而深刻的政治、社会经济、文化和生态影响。 混农季节性放牧这种古老的传统生计策略面临着许多挑战,如冬季饲料短缺、草场退化、缺乏市场竞争力、经济重要性降低、对年轻人缺乏吸引力、国家缺乏专门的政策指导等。与此同时,经济全球化、市场经济、新技术的应用、替代生计机会的增加、国家对于山地生态系统的作用的重新定位等也为传统生计系统转型、实现社会与生态共赢创造了机遇。 混农季节性放牧活动对亚高山及树线交错带生态系统系统的互动方式主要体现在以下几个方面:(1)牲口啃食、践踏等影响森林群落更新,改变森林群落的组成和结构,从而影响森林群落的演替进程和植被格局。林线边缘是搭建夏棚的首选地点,因此林线及树线交错地带就成了牲口活动的主要场所之一;(2)利用火烧开辟、维持和改良高山牧场; 3)在亚高山火灾迹地的放牧活动能够阻止火烧迹地的顺向演替; 4)牧民在林线附近获取建材和薪材等活动影响高山林线附近森林的结构和功能。 在调查区域,梅里雪山、白马雪山、甲午雪山的林线海拔高度在4200-4300m之间; 四川雅江、理塘一线,林线位置多在4300-4400m;四川壤塘二林场一带的林线主体在4100-4200m,在个别地区达到4300m; 在贡嘎山的南坡和东坡一带,林线位置在3600-3700m;而在四川松潘一带,林线位置主体在3700-3800米左右。树线高度的分布趋势和林线一致。混农季节性放牧及其有关人类利用活动使研究地区很多地方高山林线降低、树线交错带宽变窄或消失。在研究地区,总体情况是,阳坡和半阳坡(南坡、西南坡等)的林线和树线比阴坡和半阴坡(北坡、东北坡等)低,变化幅度达20-200m。这种差异主要是为了开辟牧场而人为清除了南向坡自然林线及其以上的植被从而使林线位置下降所致。在南坡自然林线保留得比较好的地方,林线和树线依然可以达到甚至超过北坡林线和树线的高度。放牧活动抑制了高山林线带火烧迹地的天然更新,从而使林线位置保持在目前的位置。 放牧活动对高山林线带森林群落更新的影响是显著的。自然林线内的乔木个体密度特别是新生苗和幼苗的密度大大高于非自然林线。没有放牧的自然林线及树线交错带内的I级个体(新生苗)密度达到725-2917株/公顷,而与之相对的处理样地内I级个体的密度只有0-228株/公顷;II级个体(高度10-50cm)也表现出类似的趋势,在没有放牧的自然林线及树线交错带样方内,其密度达到550-5208株/,而在放牧处理样方内只有14-321株/公顷。在非自然林线带样地内,在有正常放牧的样地内,完全缺乏I级个体。 从相对比例来看,没有放牧的样方内的I、II级个体在全部个体中所占的比例显著高于有放牧活动的样方。放牧使林线交错带的乔木幼苗数量显著减少,从而影响林线及树线交错带森林群落的天然更新过程。林线和树线交错带的灌木对乔木幼苗具有重要的保护作用,能够为树线树种如冷杉等幼苗的定居体提供有利的微气候环境,同时保护苗免受牲口的啃食和践踏。火烧以后接着进行放牧能够100%地抑制高山林线带的幼苗更新。 高山牧场放牧强度降低、使用时间缩短而低海拔地带放牧强度增加是研究地区混农季节性放牧系统的一个显著变化。这种变化也必然会引起各海拔带上的生态系统的变化。放牧强度的降低、生产性用火的停止将导致原来通过人工火烧而降低并通过进一步的火烧和放牧活动来维持的林线及其以上地带的灌木盖度和高度的增加,从而为林线森林群落的扩张创造条件。 青藏高原东部高山峡谷地区是我国重要的山地生态系统,在我国的生物多样性保护、生态环境建设、社会经济可持续发展战略中具有举足轻重的作用。正确认识人类特别是当地传统的生计系统与生态环境系统的互动关系是实现上述战略目标的前提。决策者必须以综合、系统的的视角协调促进社会经济可持续发展、保护生物及文化多样性和维持人、牲口和生态系统之间的平衡的多重目标。 Agropastoral transhumance, which makes a complementary exploitation of the natural resources at different altitudinal belts through a combination of migratory animal husbandry and crop cultivation, has a long history in Hindu-Kush Himalaya, Tibet Plateau, Hengduan Ranges, eastern and southern Africa and the Andes region of south America.For millennia, this traditional livelihood strategy has been one of the main forms of interaction between human societies inhabiting in these regions and their natural ecocystems. A close co-evolutionary relationship has been developed between this indigenous resources management systems and the mountain vegetation systems on the one hand and a unique set of cultural values and social features on the other. Understanding this relationship has been one of the core scientific issues in mountain ecology and anthropology. In recent years, the importance of the multiple functions of the mountain ecosystems and their dynamic changes in the sustainable socio-economic development of the mountain regions has gained increasing attention. This paper, which is based on a detailed study on the agropastoral practices of the 12 natural villages in Deqin County of Yunnan, and the mountainnn vegetation patterns in Deqin of Yunnan and Rangtang County of Sichuan, intends to reveal the major characteristics, system composition and the inter-relations of the subsystems of the agropastoral transhumance in Eastern Tibetan Plateau as well as the trends of changes of the system within the context of global changes, economic globalization and modernity process of China and analyze the relations between agropastoral transhumance and alpine ecosystem, ao as to understand the interactions between human activities and natural ecosystems of the mountains and provide theoretical basis for the national strategies in eocioeconomic development, environmental reconstruction and biodiversity conservation in the mountain regions. Results of the survey indicate that agropastoral transhumance in the investigated area is a traditional economic form that is highly adapted to the eastern Tibet Plateau where the topography features high peaks and deep gorges and where the highly variable environmental parameters and scanty natural resources exhibit a distinct vertical spectrum of distribution and great temporal and spatial heterogeneity. The main objective of pastoral management is still aimed at the production of basic goods and services of local people and thus the type and size of animals raised for each household mainly depend on local needs and are limited by the availability of natural resources. The scale of production is relatively low. Pastoral resources at different altidudinal belts are complementarily used at different seasons of a year and thus form the resources basis for agropastoral production of the study area. Migration distances and patterns vary with the location of the permanent settlements, the elevational distribution range of the resources of the villages concerned. Natural pastures (rangelands) are the main fodder resources and sumplement feedings only account for less than 5% of the total fodder consumption. Crop cultivation and pastoral activities support each other to form a complete livelihood system. The ability of the farmig lands (crop cultivation) to provide the pastoral activities with concentrates and sumplements often becomes a main factor limiting the scale of livestock production at household level. Agropastoral transhumance is experiencing drastic changes in recent decades as is reflected in the size and composition of animals, the seasonal migration pattern, the relative importance of pastoralism in the household economy and the interplays of agricultural and pastoral elements of the system. In general, there is a decline in animal population and mobility, a shift in animal composition to meet new needs arising from changed macro-economic situation, a decrease in the relative importance in the household economy and an increasing decoupling of agro&pastoral relations. The fundamental divers of these changes can be traced to environmental, social, economic, technological and cultural changes from local to global levels and such changes have further caused local changes in livestock management objectives, land use and distribution of labor forces. Changes in local livelihood systems could have profound political, socioeconomic, cultural and ecological conseuquences. Agropastoral transhumance, as an age-old traditional livelihood strategy, is facing multifacet challenges, such as winter fodder shortage, rangeland degradation, lack of market competitiveness, decrease in economic importance, lack of appreciation among the young generation and adequate policies from the government. At the same time, economic globalization, market economy, intrdoctution of new technologies, increase of alternative income generating opportunities and the national re-oreitation of policies on mountain ecosystems have all brought about new opportunities for the transformation of the traditional livelihood system and the synchronized development of local society and the environment. Agropastoral transhumance interacts with the ecosystems at the timberline and treeline ecotone mainly through the following aspects: 1)Animal browsing and stamping affect the regeneration process of the forest communities and alters the composition and structure of the forest which in turn affect the succession process and vegetation pattern of the forest communities. Forest edges are the priority locations for summer houses and therefore the timeline and treeline area becomes the major venues of aninal activities; (2)herders create, maintain and improve pastures through burning that remove the forest communities at the timeline and treeline ecotone; 3)immediate grazing on the fire sites can significantly prevent the fire sites from perogressive succession; and 4)herders harvesting of construction timber and firewoods affects the structure and functions of the forest communities at the timberline and treeline zone. Timberline position in the survey region shows geographical variations. It is around 4200-4300m in Meilixueshan, Baimaxueshan and Jiawuxueshan in Northwest of Yunnan and rises to 4300-4400m in Yajiang County and Litang County of Sichuan. In Rangtang of Sichuan, it is between 4100-4200m, though reaching 4300m in localized sites. In the southern and eastern slopes of Gongga Mountain, the timberline is only between 3600m and 3700m and in Songpan County at the upper reach of the Minjiang River the timberline is around 3700-3800m.Treeline pattern follows similar trend. In many places, agropastoral transhumance and related human activities have lowered the timberline and treeline and narrowed or removed the treeline ecotone. In the area of survey, generally speaking, timberlines and treelines are lower on the southern slopes than on the northern slopes, with a difference between 20 and 200m. This is mainly because that the use of fires to crerate pastures has removed the forest vegetation at the previous timberline and above. In fact, in many places, well-preserved forests on the south slopes have even high timberline position that the corresponding northern slopes. At subalpine zone, grazing activities could have prohibited the natural regeneration of many forest fire sites and maintained the forest position at the present level. Grazing has a significant impact on the regernation process of forest communities at the timberline zone. Natural timberline and treeline ecotone has much higher density of treeline species individuals especially the emergents and seedlings than the timberlines that are maintained by human activities. In natural timberline and treelien ecotone without grazing interference, the density of the I Class seedlings (less than 10cm in height) ranges 725-2917 /hm2; while that in the treatment plots (with grazing disturbance) is only 0-228//hm2;II Class seedlings (10-50cm)exhibit similar density trends, reaching 550-5208//hm2 in natural timberline without grazing but only 14-321//hm2 in the plots with grazing treatment. In the man-created timberlines, there is no I Class seedling at all in plots with normal grazing activities. In relative terms, in plots without grazing activities, the propotion of I Class and II Class seedlings is much higher than that in plots with grazing. Grazing activities have significantly reduced the number of seedlings in the timberline ane treeline ecotone, and thus affect the natural regeneration process of the forests. Shrubs at the timberline and treeline ecotone can effectively protect the seedlings from severe climate and animal tramping, thus increasing the survival rate of the seedlings. Grazing following fires can completely inhibit forest regeneration process at timberline. Changes in agropastoral transhumance will have great impact on the timberline and treeline pattern of the studied area. The decrease in grazing intensity on alpine pastrues and the cessation of the use of fires will result an increase in the cover and height of shrubs above the present human-maintained treeline, which will create further condition for the expansion of timberline forest communities. Eastern Tibet Plateau harbors some most important mountain ecosystems of China that are of vital importance to the country’s strategy in biodiversity conservation, environmental construction and sustainable sociaoeconomic development. A proper knowledge of the interactions between traditional livelihood systems and the ecosystems in the region is a precondition to the realization of the above strategic goals. Therefore, the decision-makers must have a holistic and systemic perspective so as to integrate the multiple objectives of promoting sustainable socioeconomic development, conserving biological and cultural diversity and maintaining the balances among people, animal population and the ecosystems.
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当前大气CO2浓度升高是全球变化的主要趋势之一,CO2浓度升高还会引起全球变暖等其它环境问题,因而CO2浓度浓度升高对植物影响的研究已经成为全球变化领域的焦点。红桦是川西亚高山地区暗针叶林演替初期的先锋树种和演替后期的建群种,在群落演替过程中它对环境因子的响应决定红桦群落的演替进程。本文通过控制CO2浓度的气候室试验,研究了CO2浓度倍增环境下,不同密度水平红桦碳氮固定、分配可能发生的改变,并探讨了升高大气CO2浓度对群体内部竞争的影响。以期通过本研究明确川西亚高山地区代表性物种红桦对未来气候变化的响应,为今后采取措施应对气候变化、妥善进行森林管理提供理论依据和科学指导。主要研究结果如下: 1.升高CO2浓度对红桦幼苗生长的影响以及树皮、树干响应的不同 (1) CO2浓度升高显著促进红桦幼苗的生物量、株高、基茎的生长,同时也改变生物量在体内的分配格局,主要是增加根和主茎、减少叶在总生物量中的比重。(2)树皮和树干对升高CO2浓度的影响有差异,它们对CO2浓度升高的反应程度不同,但反应方向一致。 2.密度的副效应 (1) 增加种植密度对单株生物量、株高和基径的生长具有副效应,也降低升高CO2浓度对红桦生长的正效应。(2) 增加种植密度,显著增加红桦幼苗的群体生物量,从而使红桦群体固定更多的大气CO2气体。可见密度在决定红桦生物量及固碳能力方面具有重要意义。探索适合未来大气CO2浓度升高条件下植物生长的密度,对未来的森林经济生产、生态恢复具有重要意义。 3. 升高CO2浓度对红桦幼苗苗冠结构及冠层内部竞争的影响 (1) 冠幅、冠高、苗冠表面积和苗冠体积等树冠特征均受CO2浓度升高的影响而增加,但是受密度增加的影响而降低。(2) 单位苗冠投影面积叶片数(LDcpa)和单位苗冠体积叶片数(LDcv)均低于相应的现行CO2浓度处理,这主要是由于冠幅和冠高的快速生长所造成的。(3) LDcpa和LDcv的降低表明,红桦在升高CO2浓度的条件下,会作出积极的响应,从而缓解由于群体和个体生长的增加所引起的竞争压力的增加。 4. 升高CO2浓度对红桦幼苗养分元素吸收与分配的影响 (1) CO2浓度升高,植株各器官N、P含量降低,但单株N、P总吸收量均增加。红桦幼苗体内N、P浓度的下降是由于生物量迅速增加引起的稀释效应造成的。(2) CO2浓度升高,N、P向主茎和根的分配增加,向叶片的分配减少,主要是由于前者在总生物量中的比重增加,而后者减少了。(3) CO2浓度升高,氮磷利用效率(NUE和PUE)提高,氮磷累积速率(NAcR和PAcR)显著增加。而NUE和PUE的提高可以有效缓解CO2浓度升高后,亚高山和高山地区森林土壤中养分元素不足对森林生产力的限制。 5. 升高CO2浓度对红桦幼苗群体碳平衡的影响 (1) 升高CO2浓度对植物的光合作用、呼吸速率和生长均具有促进作用。(2) 土壤有机碳含量在实验前期迅速增加,后期积累速率下降。(3) 升高CO2浓度以后,土壤呼吸显著增强;土壤呼吸还具有明显的季节变化。(4) 红桦群体日固碳量受到升高CO2浓度的促进作用。结果(1)-(4)说明所研究群落的碳动态对现行的气候波动是敏感的;所研究群落在作为大气CO2气体的源-汇关系方面至少存在季节间的源汇飘移。(5)种植密度的升高显著增加了群体固碳量。 6. 升高CO2浓度对红桦幼苗生长后期叶片衰老的影响 升高CO2浓度有利于减缓红桦幼苗叶片生长季节末期的衰老。生长季节末期,随着CO2浓度的升高光合速率和可溶性蛋白含量均呈上升趋势,同时MDA(丙二醛)含量下降,保护酶SOD(超氧化物岐化酶)、CAT(过氧化氢酶)活性升高。由此说明,升高CO2浓度有利于减缓生长季节后期叶片的衰老,使叶片维持较高的光合速率,也从生理学的角度支持了本文及前人有关CO2浓度升高促进植物光合和生长的假说及结果。 The increased CO2 concentration is one of the most important problems among global changes. The increase of CO2 will also cause other environmental problems, such as global warming, etc. So the effects of elevated CO2 on plant have drawn sights of many scientists in the research field of global change. Red birch (Betula albosinensis) usually emerges as the pioneer species in initial stage and as constructive species in later stages of forest community succession of the dark coniferous forests in Western Sichuan, China. It’s response to elevated CO2 may determine the succession process of the community where it lives in. By controlling CO2 at the ambient and twice as the ambient level (ambient + 350 umol mol-1) using enclosed-top chambers (ETC), possible effects of elevated CO2 on carbon fixation and allocation under two plantation densities are investigated. The effects of elevated CO2 on competition within canopy of red birch seedlings are also observed in the present paper. We hope to make sure of the effects of elevated CO2 on the representative species, red birch. And so that, our results could provide a strong theoretical evidence and scientific direction for forest management and afforestation under a future, CO2 elevated world. The results are as fowllows: 1. The effects of elevated CO2 on growth and the different responses of wood and bark of red birch seedlings (1) Elevated CO2 increases the growth of seedling biomass, seedling height and basal diameter of red birch. It also changed the biomass allocation in red birch seedlings. The ratio of root and main stem to all biomass is increased and the ratio of leaf is decreased. (2) Tree bark and wood show different response degree but similar response direction to elevated CO2. 2. Negative effects of planting density (1) The increase of planting density showes negative effects on the individual growth of seedling biomass, seedling height and basal diameter of red birch. It also eliminates the positive effects of elevated CO2 on growth of red birch seedlings. (2) Community biomass is increased by the elevated planting density, which means that the high density red birch community could fix more CO2 than the low density one. These results show that planting density plays an important role in determining biomass and carbon fixation ability of red birch community. Thus, exploring proper planting density becomes economically important for the future, CO2 elevated word. 3. The effects of elevated CO2 on crown architecture and competition within canopy of red birch seedlings (1) Crown width, crown depth, crown surface area and crown volume are all increased under the influence of elevated CO2. (2) Leaf number per unit area of projected crown area (LDcpa) and per unit volume of crown volume (LDcv) are lower under elevated CO2. This is resulted from the stimulated growth of tree crown features. (3) The decrease of LDcpa and LDcv indicate that plants will respond forwardly to reduce the possible increase of competition resulted from stimulated growth of individual plant and collectives in conditions of elevated CO2. 4. The effects of elevated CO2 on nutrition accumulation and allocation of red birch seedlings (1) Contents of N and P decrease due to the prompt increase of biomass of plant organs caused by elevated CO2. However, their accumulations increase under elevated CO2. (2) Elevated CO2 increases the allocation of N, P to main stem but reduced its allocation to leaf for that dry weight of the former increased but the dry weight of the later decreased. (3) Using efficiencies of N, P (NUE and PUE) and their accumulation rates (NAcR and PAcR) are found to increase under elevated CO2. Soil nutrition contents are always the limiting factors for plant growth at subalpine and alpine region. The increased NUE and PUE are helpful to eliminate the nutrition limitation in this area in the future world, when CO2 concentration doubles the ambient. 5. The effects of elevated CO2 on carbon balance of red birch communities (1) Net photosynthetic rates (Pn), dark respiration rates (Rd) and growth are all stimulated by elevated CO2. (2) Content soil organic carbon increases sharply at the primary stage of experiments and then the increasing rates decrease to a low level at later stages. (3) Soil respiration rates increase significantly with the elevation of CO2 concentration. (4) The daily carbon fixations of whole community are heightened by elevated CO2. The results (1)-(4) suggest that, the community being studied are sensitive to current climate change; the studied community, as a sink of atmospheric CO2, is pool-sink alternative between seasons. (5) The carbon fixations are increased along the increase of planting densities. 6. The effects of elevated CO2 on physiological features of leaf senescences of red birch seedlings at the later stage of growing season Elevated CO2 helps to postpone the leaf senescences of red birch at the end of the growth season. CO2 enrichment increases the photosynthetic rates, contents of soluble proteins and photosynthetic pigments. And meanwhile contents of malondialdehyde (MDA) decreases and activities of superoxide dismutase (SOD) and catalase (CAT) are both increased. These results suggest that the senescences of red birch leaves are delayed by elevated CO2, which keep the photosynthetic rates at relatively high levels. Our results lend supports to hypothesis and results on stimulated photosynthetic rates and growth from both other researchers and the present paper.
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近二十多年来,基于对臭氧层衰减、紫外线B(UV-B)增强的担心,研究者希望了解到紫外线辐射对不同作物的影响情况,增强UV-B辐射条件下是否对作物的生长发育、产量质量构成威胁。在本试验中,我们首先探讨了双子叶作物黄瓜(Cucumis sativus)和大豆(Glycine max)对不同紫外波段的生物效应[分别为B-UVA(315-400 nm),N-UVA(315-340 nm),B-UVB(275-400 nm)和N-UVB(290-340 nm),UV-(>400nm)作对照]。我们观察到所有的UV波段处理都使黄瓜和大豆的生长受到抑制,并且细胞受到不同程度的氧化伤害;UV波段处理的作用效果与不同波段的紫外有效生物辐射剂量有关。处理差异在UV-B波段内部和UV-A波段内部同样存在。植物生长UV辐射公式(BSWF)能很好的预测本试验UV-B波段内的平均植物效应,但不能预测UV-A波段的植物效应。短波UV-A的生物作用强于长波UV-A。光合色素的变化与UV波谱差异和种间差异有关。在高的紫外/可见光背景下,UV-A处理同UV-B同样导致光合色素的降低,但黄瓜类胡萝卜素/叶绿素比例升高。与其他研究者的试验结果比较后,我们认为紫外线B辐射的生物效应一致性很高,但紫外线A波段的生物学效应存在较大争议。因此我们在本试验的基础上仅进行荞麦[苦荞(Fagopyrum tataricum Gaertn.)和甜荞(Fagopyrum esculentum Moench.)]对紫外线B波段的响应研究。 我们对苦荞品种-圆籽荞进行了连续两个生长季节的大田半控制试验以观察UV-B辐射对苦荞生长、发育、产量及叶片色素的影响;试验小区进行降低UV-B、近充足UV-B和增强UV-B辐射处理。我们的试验表明在不同强度UV-B辐射下苦荞的生长、地上部生物量积累及最终产量都有所下降,但苦荞的发育加快;当前条件下的日光紫外线B辐射对植物生长和产量也造成负面影响。植物光合色素被日光及增强UV-B辐射降低;UV化合物及卢丁含量在中低剂量的UV-B辐射强度下显著升高,但在高剂量的增强UV-B辐射下短期升高后迅速下降。我们的试验表明苦荞是一个对UV-B高度敏感的作物。苦荞对UV-B的敏感性与UV-B剂量、外界环境因素及生长季节有关。 单个苦荞品种的试验结果使我们认识到外界UV-B辐射已经对苦荞生长发育构成逆境条件,未来全球气候变化条件下增强紫外线B辐射可能使其处于更不利的生长环境中。因此我们有进行了多个种群进行UV-B响应观察并筛选耐性种群。我们对15个苦荞种群进行增强UV-B辐射处理(6.30 kJ m2 UV-BBE,模拟当地25%的臭氧衰减),我们观察苦荞UV-B辐射效应存在显著的种内差异,UV-B辐射对多数种群具有抑制作用,但对一些种群还有刺激作用。我们采用主成分分析方法与作物UV-B响应指数(RI)来评价苦荞作物UV-B辐射耐性。我们发现作物的UV-B耐性不仅与其原产地背景UV-B强度有关,而且与作物相对生长效率、次生代谢产物含量(如卢丁)及其他因素有关。我们观察到苦荞伸展叶总叶绿素变化与UV-B耐性成正相关;室内苦荞幼苗的UV-B辐射致死试验表明:苦荞种群死亡率与其UV-B耐性成负相关。 此外,我们对甜荞的UV-B辐射响应也进行了初步研究。选取美姑甜荞、巧家甜荞和云龙甜荞进行5个梯度的增强UV-B辐射室外模拟试验。我们观察到UV-B辐射显著降低了甜荞的生长、生物量及产量;并严重影响了甜荞的生殖生长,降低了花序数、种子数和结实率;并且UV-B辐射对甜荞的抑制作用存在显著的剂量效应。三种甜荞品种存在显著的种内差异,其中美姑品种UV-B耐性最强,且膜脂受UV-B辐射氧化伤害最小,这与该品种UV-B辐射下较高的GR酶活性、APX酶活性和PPO酶活性、以及含量更高的抗坏血酸有关。甜荞的次生代谢也受到增强UV-B辐射的影响,其香豆酰类化合物在UV-B辐射下升高显著,而槲皮素含量也在高剂量UV-B辐射下有所增加;卢丁含量依赖UV-B辐射剂量而变化,中低剂量UV-B辐射下其卢丁含量逐渐升高,但在高剂量辐射下逐渐下降。 通过对生长在高海拔地区的荞麦作物(苦荞和甜荞)进行的室外研究,我们认识到作物不同品种存在很大的耐性差异,这就为UV-B耐性育种创造了有利条件。进一步加大荞麦种质资源筛选力度并深入认识荞麦抗性机理,在此基础上通过杂交或其他基因融合手段培育抗性品种,对高剂量UV-B辐射地区的荞麦产量的提高将起到重要推动作用,并使荞麦生产能有效应对未来全球气候变化条件下UV-B辐射可能升高的威胁。 During last few decades, due to concern of ozone layer depletion and enhancement of ultraviolet B radiation(UV-B, 280-315 nm), the agronomist want to know the responses of different crop species to UV-B. In the first experiment of our study, the effect of different UV band [B-UVA(315-400 nm), N-UVA(315-340 nm), B-UVB(275-400 nm), N-UVB(290-340 nm)and UV-(>400nm, as control)] on the cucumber(Cucumis sativus)and soybean(Glycine max)were investigated in growth room. Spectra-dependent differences in growth and oxidation indices existed within UV-A bands as well as UV-B bands. The general biological effects of different band were UV- < B-UVA< N-UVA<N-UVB<B-UVB. The plant growth biologically spectra weighting function(BSWF)matched well with average plant response in UV-B region, but not in UV-A region. Shorter UV-A wavelength imposed more negative impact than longer UV-A wavelength did in both species. The effect on photosynthetic pigment was related to different UV bands and different species. The photosynthetic pigment content was decreased by UV-A spectra as well as UV-B spectra. In comparison with the results of previous studies, we found that the wavelength-dependent biological effect of ultraviolet B radiation has high consistency, but the biological effect of ultraviolet-A radiation was inconsistent. We narrow our following study on the effect of ultraviolet B radiation on the buckwheat(tartary buckwheat and common buckwheat). The tartary buckwheat(Fagopyrum tataricum Gaertn.)cultivars Yuanziqiao was grown in the sheltered field plots for two consecutive seasons under reduced, near-ambient and two supplemental levels of UV-B radiation. The crop growth, photosynthetic pigments, total biomass, final seed yield and thousand-grain weight were decreased by near-ambient and enhanced UV-B radiation, while crop development was promoted by enhanced UV-B radiation. Leaf rutin concentration and UV-B absorbing compound was generally increased by UV-B with the exception of 8.50 kJ m-2 day-1 supplemental levels. Our results showed that tartary buckwheat is a potentially UV-B sensitive species. Study on one cultivars showed that ambient solar radiation had present a stress to tartary buckwheat. This makes it necessary to observe the UV-B response of many cultivars and screen tolerant cultivars. Fifteen populations of tartary buckwheat were experienced enhanced UV-B radiation simulating 25% depletion of the stratospheric ozone layer in Kunming region, and plant responses in growth, morphology and productivity were observed. Principal components analysis(PCA)was used to evaluate overall sensitivity of plant response to UV-B as well as response index. The different populations exhibited significant differences in responses to UV-B. The photosynthetic pigments of young seedlings were also affected significantly under field condition. On the other hand, the healthy seedlings of different populations were exposed to the high level of UV-B radiation in growth chambers to determine the plant lethality rate. The plant tolerance evaluated by multivariate analysis was positively related to total plant chlorophyll change, but negatively related to lethality rate. In other hand, the UV-B responses of the other important cultivated buckwheat species, common buckwheat(Fagopyrum esculentum Moench.), were also studied preliminarily. Three widespread cultivated variety(Meigu, Qiaojia and Yunlong cultivars)were provided with five level of enhanced UV-B radiation outdoors. We observed that the crop growth, development and production were significantly decreased, and reproductive production, like anthotaxy number, seed number and seed setting ratio, was also decreased. Dose-dependent inhibition effect caused by enhanced UV-B radiation also existed in common buckwheat. Significant intraspecific difference existed in those three cultivars. The Meigu cultivars with dwarfed growth and lower production have highest UV-B tolerance as well as lowest damage in cell membrane, this could be associated with profound enhancements of glutathione reductase(GR)activity, ascorbate peroxidase activity and polyphenol oxidase activity as well as higher ascorbic acid concentration. The secondary metabolism was also affected by UV-B radiation, with profound elevation of coumarin compound and moderate increase of quercetin concentration. Rutin concentration was peaked in 5kJ m-2 UV-B. The contrasting effect of UV-B radiation on different populations indicated that there existed abundant genetic resources for selecting tolerant populations of common and tartary buckwheat. Much effort needed be pose on screening of buckwheat germplasm and clarification of mechanism of buckwheat tolerance to UV-B. On this base the tolerant cultivars could be bred by hybridization and other gene transfusion method, this would help increase buckwheat yield in high ambient UV-B region and counteract the effect of possible enhanced UV-B radiation in future.
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本文考察了若尔盖高寒泥炭湿地公路对高原林蛙(Rana kukunoris)、倭蛙(Narorana pleskei)和岷山蟾蜍(Bufo minshanicus)的生态影响。分析了公路对两栖动物空间分布和栖息地利用的影响,并用IBM模型探讨其可能作用机制,考察了两栖动物公路死亡的季节差异及影响公路死亡空间分布的景观因素。最后通过对若尔盖高寒湿地两栖动物陆地核心栖息地的分析,为若尔盖路域栖息地的管理提供依据。 1. 对公路周边6个沼泽水凼群进行了调查,每个样地设置5条样线(距离公路10m、20m、50m、100m和150m)。调查表明,在繁殖季节(5月),距离公路距离对高原林蛙和倭蛙的相对数量都有显著作用,其效应明显大于其他各项栖息地环境参数。公路导致高原林蛙和倭蛙在公路周边种群密度降低,其相对数量从距离公路100m处到公路边缘一直呈现逐渐降低的趋势。在繁殖季节,若尔盖高寒湿地的公路生态影响域大约在100-150m之间,这一距离远远大于森林栖息地中公路对两栖类的生态影响域(35-40 m)。 在繁殖后期(9月),对公路周边16个草地样点的样线调查表明,公路对周边高原林蛙和倭蛙密度分布并未造成显著影响。 2. 二次模型的拟合表明繁殖季节高原林蛙和倭蛙在公路周边的密度分布符合钟型曲线。前人对森林公路两侧两栖类分布的研究也显示了类似的规律。我们通过基于个体的模型,模拟在了公路边缘100单位距离内的栖息地空间,栖息地环境质量呈梯度变化,动物个体在其中通过随机运动寻找适宜的栖息地。拟合结果表明,动物个体仅仅依照简单的运动规则寻找适宜栖息地,这种活动就可以导致公路周边栖息地中的动物分布曲线出现3个局部峰。公路周边两栖动物的钟型分布曲线可能仅仅是个体寻找适宜栖息地过程中出现的临时性群体分布模式。 3. 在若尔盖高寒湿地,公路交通造成了大量两栖类死亡。但是公路两栖类动物死亡的季节分布很不均匀:5月、8月和9月死亡数量很高,而7月和10月死亡数量却很低。这种季节性差异和两栖类各个生活史阶段的迁移运动有密切的关系。利用景观参数的逻辑斯蒂回归模型显示,距离公路1000-2000m范围内的湿草地比例对三种两栖类公路死亡概率均有很强的贡献。湿草地这一栖息地类型分类中有大量的沼泽水体,是两栖类重要的繁殖点和取食点。两栖类公路死亡概率湿草地的关系从一个侧面表明,要维持一个区域较高的两栖类种群数量,需要1000-2000m半径范围内存在大面积的湿草地。 4. 高原林蛙和岷山蟾蜍不同性别和年龄个体分布点的水体距离存在显著差异。不同种类、年龄的两栖类分布点距离水体距离的差异可能是由于对水体的依赖性造成的。而相同种类、年龄段的个体中,高原林蛙雌性、岷山蟾蜍亚成体和雌性的体重与分布点距水体距离有显著负相关,这可能是因为体重更大的个体对水体的依赖性更弱。考虑到过大的陆地核心栖息地面积在实际保护工作中存在操作上的困难,因此我们认为可以以水体周边90%个体的分布区为低限确定3种两栖类的最小陆地核心栖息地。但是,在同样的水体距离-两栖类密度分布格局下,水体的面积和分形参数对最小陆地核心栖息地半径的确定有一定影响。 Ecological effects of alpine wetland road on Rana kukunoris, Narorana pleskei, Bufo minshanicus was studied in Zoige wetland. The effects of road on distribution of amphibians and its possible underline mechanism was discussed based on empirical data and computer simulation. Road killed amphibians was surveyed in different season and those landscape factor which could have impact on road killing distribution was analyses. Core terrestrial habitat of amphibians in Zoige wetland was discussed in the consideration of conservation management. 1. Six pool groups was investigated in breeding season (May) of R. kukunoris, N. pleskei. Five transects at distance of 10m, 20m, 50m, 100m and 150m from road edge was surveyed in each pool groups. There was a significant effects of distance from road edge on relative counts of R. kukunoris, N. pleskei, which is much important than effects of other environmental factors. Road caused the density of R. kukunoris, N. pleskei decreased from distance of 100m from road to 10m from road. Road ecological effect zone of alpine wetland for amphibians is about 100-150m. It is much wider than those of forest roads, which is about 35-40m. However, studies on 16 grassland near road showed no significant effect of road on amphibians after breeding season (Sep.). 2. Quadratic model fit indicated that the distribution of R. kukunoris and N. Pleskei followed a hump like curve. Previous studies on forest road showed similar results. A 100×100 habitat with gradual environment besides road was simulated with a individual-based model, and animal seek for suitable habitat with stochastic locomotion in it. Simulation results indicated that 3 density peak of animal distribution can emergent followed a simply rules. The hump like density cure could be a temporal swarm pattern during the process of individual seeking for habitat. 3. Road traffic caused mass death of amphibians in Zoige wetland. There was much road killed amphibians in May, Aug and Sep than those in July and Oct. The fluctuation of road kill could be related with migration of amphibians between seasons. Logistic regression of landscape variables indicated that wet grassland in 1000-2000m is essential to predict the probability of road kill. Wet grassland is an important breeding and forage habitat for amphibians. It also indicated that mass wet grassland in 1000-2000m is essential for maintain a big amphibian population. 4. There was significant differences among distance from aquatic site of subadults, female and males of R. kukunoris and B. Minshanicus. Possibly, it was because of their dependence on water. There was a significant negative relationship between distance from aquatic site and individuals body mass. Estimates of core habitat that are too large may make it difficult to establish protective regulations. The smallest suitable terrestrial core habitats were defined as the terrestrial habitats used during migration to and from the wetlands, and for foraging by 90% of any life stage (adults, and subadults) in a season. However, even with the same amphibian distribution pattern along the distance from aquatic sites, the radii of smallest suitable terrestrial core habitats will be varied with the fractal parameters of aquatic site.
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本文主要研究了泸州老窖古酿酒作坊内外环境空气真菌和空气细菌的群落结构和分布特征。结果如下: 作坊内外环境空气微生物浓度差别显著,并随季节变换而变化,春、夏季微生物浓度较高,秋、冬季较低,空气真菌在夏季达到最高,细菌在春季最高。 古作坊内外环境检测到的真菌均为16 属,但优势菌属不同,作坊外的优势菌属为青霉属(Penicillium)、曲霉属(Aspergillus)、无孢菌(non-sporing)、枝孢霉属(Cladosporium)和链格孢属(Alternaria);而作坊内优势菌属为曲霉属、青霉属、酵母菌(Yeast)、无孢菌,作坊内还含有较高浓度的根霉属(Rhizopus)、毛霉属(Mucor)、短梗霉属(Aureobasidiu),枝孢霉属和链格孢属等,曲霉属、酵母菌、根霉属、毛霉属为古酿酒作坊重要的酿酒真菌,青霉属、链格孢属为酿酒不利菌群。对古作坊内曲霉属进行了初步鉴定,主要是小冠曲霉(A.cristatellus)、米曲霉(A.oryzae)、黑曲霉(A.niger)和白曲霉(A.cadidus)。 空气细菌10 属21 种,作坊内外环境的优势菌属均为芽孢杆菌属(Bacillus)、微球菌属(Micrococcus)、葡萄球菌属(Staphylococcus)、假单胞菌属(Pseudomonad),其中芽孢杆菌属在作坊内占有绝对的优势,浓度比在40℅以上,是古酿酒作坊重要的酿酒细菌,另外还检测到较高浓度的乳酸杆菌(lactobucillus),这类菌容易使酒味发涩发苦,为酿酒不利菌。 作坊内外环境空气微生物表现出明显的交流现象。作坊内,青霉属、枝孢霉属、链格孢属、葡萄球菌属等杂菌占有一定比例;而在作坊外,芽孢杆菌属、曲霉属、根霉属(Rhizopus)、酵母菌等处于相对较高水平,绿化环境较好的营沟头作坊内的短梗霉属,枝孢霉属和链格孢属等杂菌含量低于什字头和新街子作坊。 The community structure and distribution characteristic of airborne microbes was investigated in ancient brewage workshops of luzhoulaojiao. The results are as follows: The concentration of airborne microbes was different in interior and exterior environment of ancient workshops, and also varied by seasons. microbial concentration was higher in spring and summer, and lower in fall and winner. The highest levels of airborne bacteria was in spring, but the fungal’s in summer. The identified genus of fungi were 16 in interior and exterior environment of the ancient workshops. But the dominant genus were different , The advantage genus in the interior were Aspergillus, Yeasts, Penicillum and Nonsporing and in the exterior were Penicillum, Nonsporing, Cladosporium, Aspergillus and Aureobasidiu. Rhizopus ,mucor, Aureobasidiu, Cladosporium, Alternaria and all also were at a higher level. Among these, Aspergillus, Yeasts, Rhizopus ,mucor are important vintage flora . Penicillum, Alternaria do harm to vintage. Aspergillus of ancient workshops was identified , the preponderant aspergillus species were A.cristatellus, A.oryzae, A.niger and A.cadidus in ancient brewage workshops. 10 genus 21 species bacteria were identified, the advantage genuses among the interior and exterior of the three workshops were bacillus, microccus, Staphylococcus Pseudomonas. Bacillus, which account for beyond 40℅ of the total bacteria concentration in all sampling pots, was the most dominant genus. Lactobacillus was identified at a high level in ancient workshops, it makes spirit taste bitter and astringent. So it is not a kind of good bacterium for vintage. The fungus in the interior and exterior atmosphere characterized intercommunion phenomenon. Obviously, the concentration of profitless fungus such as Penicillum, Cladosporium, Alternaria appeared in the interior, and the fungus such as Bacillus, Aspergillus, Rhizopus and Yeasts in the exterior were at a relatively high level. the harmfull fungus in yinggoutou workshops such as Aureobasidiu, Cladosporium, Alternaria and all were lower than shenzitou and xinjiezi workshops.