节点文献

施肥对茶树及茶园动物群落的影响

Effects of Fertilization on Tea Plants and Animal Communities in the Tea Plantations

【作者】 陈少波

【导师】 尤民生;

【作者基本信息】 福建农林大学 , 生物防治, 2008, 博士

【摘要】 氮和磷是控制陆地和水生态系统的物种组成、多样性、动态和功能的两个最重要的营养限制因素。目前,有关肥料对生态系统的营养效应已有很好的研究,但关于施肥对植食者的影响及其造成的群落和生态系统特性的变化,人们还知之甚少。为此,我们于2004-2005年在福建省武夷山系统研究了茶树营养管理措施(不同肥料、不同氮肥水平)对茶树生长和生理及茶园动物群落组成结构和多样性的影响;分析了茶树生产力和生化品质变化与茶园动物群落的组成结构和多样性变化以及有害动物发生的关系;阐明了施肥影响茶园动物群落多样性的机理,并为制订茶树有害生物与营养综合管理策略提供科学依据。1.不同肥料对茶树生长和生理的影响施NPK、N显著提高茶树生产力(新梢生物量)和产量,且以NPK配施为最佳;施用有机肥、PK虽提高茶树生产力和产量,但未达显著水平。肥料处理对茶树的全氮、氨基酸、咖啡碱、总糖和茶多酚的含量以及碳氮比和酚氨比产生显著影响,且在不同月份其影响不同;但对茶树总碳含量无显著影响。施NPK、N、PK和有机肥都显著提高茶树全氮、总氨基酸及各种氨基酸含量,且茶树全氮、总氨基酸及各种氨基酸含量都是NPK和N处理显著高于PK和有机肥处理。4种肥料施用都会显著降低茶树碳氮比,且以NPK和N处理降低最多。施NPK、N和PK都显著提高茶树咖啡碱含量,而有机肥对茶树咖啡碱含量无显著影响。施NPK、PK均显著提高茶树总糖含量,且NPK处理显著高于PK处理;而施有机肥、N对茶树总糖含量无显著影响。施NPK和N都会显著降低茶树茶多酚含量和酚氨比,而施有机肥和N则对茶树茶多酚含量和酚氨比无显著影响。2.不同施氮水平对茶树生长和生理的影响茶树生长表现出对氮的适度响应,其生产力(新梢生物量)及产量与施氮水平呈二次抛物线的回归关系,在施氮量为732.60 kg·ha-1·y-1和769.26kg·ha-1·y-1时分别达到最大生产力和产量。茶树全氮、咖啡碱、总氨基酸及各种氨基酸的含量与施氮水平通常呈二次抛物线或直线的回归关系,通常过高施氮并不会造成其含量的持续升高,而是达到饱和状态(saturation)或下降。茶树总氨基酸及各种氨基酸对施氮的响应,因时间不同而发生变化;其在很大程度上取决于茶树氮的状况。茶树茶多酚含量及碳氮比和酚氨比通常随施氮水平提高而减少。适度施氮促进茶树总糖含量的提高,高氮使其下降。茶树新梢和成熟梢的氨基酸和总糖的含量、新梢咖啡碱含量和成熟梢总碳含量与其全氮含量显著正相关,茶树新梢和成熟梢的碳氮比和酚氨比、新梢硝态氮含量和成熟梢的茶多酚含量与其全氮含量显著负相关,而成熟梢的咖啡碱含量与全氮含量呈二次曲线回归关系,但新梢总碳、茶多酚含量与全氮含量无显著相关。茶树新梢和成熟梢的全氮、氨基酸、咖啡碱和总糖的含量都与碳氮比显著负相关,茶树成熟梢的茶多酚含量以及新梢和成熟梢的酚氨比都与碳氮比显著正相关,但茶树新梢和成熟梢的总碳含量以及新梢茶多酚含量与碳氮比无关。表明全氮含量和碳氮比可以较好反映茶树的生化品质,但它们都不能反映新梢茶树总碳和茶多酚含量的变化。因此,在研究茶树的生化品质与植食者关系时,应将全氮含量、碳氮比和茶多酚含量都作为重要的生化指标。过度施氮造成茶树生产力下降的主要原因在不同的茶季有明显的不同。春梢:过度施氮使茶树氨基酸代谢下降,不利于蛋白质的合成与积累;夏梢:过度施氮使茶树总糖含量下降;秋梢:过度施氮使茶树氨基酸、咖啡碱代谢下降,不利于蛋白质的合成与积累;进而影响茶树的生长。而不是过去人们认为的:过高的氮或硝态氮含量对茶树的毒害作用,影响茶树生长。3.茶园动物群落的组成结构和多样性在武夷山茶园共采集到149,725个动物个体,分别隶属于3门、8纲、31目、252科、1188种。其中,植食者450种(占总物种数的37.88%)、捕食者323(占27.19%)、寄生者133种(占11.20%)、腐食者230种(占19.36%)、杂食者52种(占4.38%)。在动物群落中,同翅目、疥螨目、柄眼目、鞘翅目为生态优势类群,而柄眼目、直翅目和鳞翅目则为资源优势类群。98.99%的动物物种为稀有种或偶见种,而90.91%的物种为资源次要种。动物群落及植食者、捕食者、寄生者和腐食者的种—多度关系同时符合对数正态分布和对数序列分布,而杂食者的种—多度关系则符合对数序列分布。动物群落及各营养类群的多样性、丰盛度及均匀性都呈现明显的季节消长规律,但其变化趋势有所不同。动物群落及各营养类群的多样性指数与物种丰富度和均匀度一致,动物群落稳定性与群落多样性和均匀性极显著正相关。物种丰富度随着抽样样方面积增加呈幂函数增长,动物丰盛度(个体总数和总生物量)随抽样样方面积增加直线增长。中间小区的物种丰富度、个体数和生物量都与其相邻4个小区对应的物种丰富度、个体总数和生物量的平均值极显著直线正相关。动物群落、植食者、捕食者、腐食者和杂食者以及半翅目、同翅目、鞘翅目、鳞翅目、膜翅目、双翅目和蜘蛛目的物种丰富度随个体数增加呈幂函数增加,而寄生者和直翅目的物种丰富度随个体数增加而直线增加。表明动物群落物种丰富度和丰盛度受其抽样样方大小和空间格局的影响,动物群落、各营养类群和各目的物种丰富度还与丰盛度(个体数)有密切关系。综合考察物种的生态优势度和资源优势度,茶园重要有害动物有扁恰里螺Kalielladepressa(Moellendorff)、黄圆蚧Aonidiella citrine(Coquillet)、假眼小绿叶蝉Empoasca vitisGothe、茶蚜Toxoptera aurantii Boyer、黑翅粉虱Aleurocanthus spiniferus Quaintance、露尾甲Haptonchus luteolus Erichsom、柑桔粉虱Dialeurodes citri Ashm、螟蛾sp.1、油桐尺蠖Buzurasuppressaria Guenee、同型巴蜗牛Brddybaena similaris(Ferussac)和短脚异斑腿蝗Xenocatantops brachycerus(Willenmse);重要捕食性天敌有圆果大赤螨Anystis baccarumLinnaeus、日本管蛛Trachelas japonicus Boesenberg et Strand、草间小黑蛛Erigonidiumgraminicolum(sun de Vall)、吸螨sp.、白斑猎蛛Evarcha albaria(L.Koch)、日本条螽Ducetiajaponica Thunberg、环斑猛猎蝽Sphedanolestes impressicollis St(?)l、南方小花蝽Orius similisZheng、斜纹猫蛛Oxyopes sertatus L.Koch和三突花蛛Misumenops tricuspidatus(Fabricius);腐食者优势种有甲螨sp.和等节(?)sp.。但寄生性和杂食性类群没有明显的优势种。4.茶园动物物种多样性、丰盛度、个体大小(bodysize)的关系茶园动物物种多样性、丰盛度、个体大小的关系的研究结果表明,在茶园动物群落、各营养类群和物种最丰富的8个目(半翅目、同翅目、鞘翅目、鳞翅目、膜翅目、直翅目、双翅目和蜘蛛目)中,物种丰富度和丰盛度与个体大小的关系均呈现单峰分布模式,且都可以用抛物线方程来拟合。不论是动物群落、各营养类群、还是物种最丰富的8个目,都是个体中等的物种数最多。在动物群落、植食者、腐食者及同翅目昆虫中,个体较小的物种的个体数最多;而捕食者、寄生者、杂食者和其它7个目则是个体中等的个体数最多。物种个体大小是由其所处的目分类阶元、营养类群以及目分类阶元和营养类群的互相作用共同决定的,表明生物进化史和营养角色(trophic role)是限制物种个体大小的重要因素。动物个体大小等级(body size class)的物种丰富度(Si)与其个体数(Ii)的关系模型为Si=1.511 Ii0.436。在捕食者、腐食者、寄生者和杂食者以及多数的目(同翅目除外)中,个体大小等级的物种丰富度与其对应的个体数也呈相似的幂函数关系;但在植食者和同翅目昆虫中,个体大小等级的物种丰富度与其对应的个体数则呈更复杂的幂函数关系。只有部分(26%)捕食者的体重比其猎物的体重大,大多数捕食者的丰盛度(个体数、生物量)比其猎物的丰盛度小。捕食者的体重、个体数和生物量都与其对应的猎物的体重、个体数和生物量极显著正相关。5.不同肥料对茶园动物群落的影响及其机理施有机肥、PK提高动物群落物种丰富度在各个目的分布均匀性,而施NPK和N则降低其均匀性。施4种肥料都会提高动物群落物种丰盛度分布均匀性,尤以PK和有机肥对其均匀性提高最多。但不同肥料对各营养类群物种丰富度在各个目的分布均匀性和物种丰盛度分布均匀性以及物种最丰富的8个目的物种丰富度在各个科的分布均匀性产生不同的影响。施N和NPK显著提高动物群落物种丰富度,施有机肥、N和PK显著提高动物群落多样性指数;但施PK和有机肥对其物种丰富度,施NPK对动物群落多样性指数均无显著影响。施有机肥显著提高了植食者有效多样性(eH’),却减少了腐食者物种丰富度;施N显著增加腐食者物种丰富度;4种肥料对各营养类群的其它多样性指标都无显著影响。施有机肥减少半翅目昆虫物种丰富度,施N和NPK提高同翅目昆虫有效多样性(eH’);4种肥料对物种最丰富的8个目的其它多样性指标都无显著影响。施有机肥和PK显著降低动物个体总数,施NPK显著提高动物总生物量,但施N和NPK对个体总数,施有机肥、PK和N对总生物量均无显著影响。施有机肥显著减少植食者、捕食者和腐食者的个体数以及腐食者生物量;施NPK显著增加植食者生物量,却减少捕食者和腐食者个体数;施PK显著减少腐食者个体数;4种肥料对各营养类群的其它丰盛度指标都无显著影响。施有机肥和PK会显著减少同翅目昆虫的个体数和生物量,施N显著增加了鳞翅目昆虫生物量;4种肥料对物种数最多的8个目的其它丰盛度指标都无显著影响。结果表明,施有机肥和PK有利于有害动物(特别是同翅目害虫)的控制,但由于植食者和腐食者数量的减少也使捕食者数量显著减少;适量施氮并不会带来有害动物数量剧增。不同肥料对18个重要物种(丰盛度最高的8种植食者、8种捕食者和2种腐食者)的个体数产生不同的影响。不同肥料对植食者假眼小绿叶蝉、茶蚜、柑桔粉虱、露尾甲和恰里螺,捕食者圆果大赤螨、日本管蛛和草间小黑蛛以及腐食者等节姚sp.个体数都有显著影响,对其它3种植食者黑翅粉虱、黄圆蚧和螟蛾科sp.1,5种捕食者吸螨sp.、斜纹猫蛛、八斑球腹蛛、微蛛sp.1和白斑猎蛛,以及腐食者甲螨sp.的个体数都无显著影响。施有机肥和PK显著提高动物群落均匀性,但施NPK和N则无显著影响。施有机肥显著提高植食性类群均匀性,施有机肥、PK和N都会提高鳞翅目昆虫的均匀性;施肥对其它营养类群和其它7个目的均匀性无显著影响。施有机肥和PK主要通过提高S/N(反应群落物种间数量上的制约潜能)来提高动物群落稳定性,而施NPK和N对动物群落稳定性无显著影响。施肥引起茶园动物群落物种丰富度变化是茶树生产力(新梢生物量)及总糖和茶多酚的含量的变化的综合作用的结果;而动物群落物种丰盛度变化是茶树生产力(新梢生物量)及氨基酸和总糖的含量的变化的综合作用的结果。各营养类群的物种丰富度和丰盛度以及18个重要物种的丰盛度对不同施肥有不同的响应机制,其通常也是茶树生产力和多个生化指标综合作用的结果。研究结果证明,施肥对茶园生态系统的整个食物链产生深刻的影响。6.不同施氮水平对茶园动物群落的影响及其机理施氮降低动物群落及捕食性和腐食性类群的物种丰富度在各个目的分布均匀性,却提高植食性类群的物种丰富度在各个目的分布均匀性;且不同施氮水平的影响程度有所差别。不同施氮水平对物种最丰富的8个目的物种丰富度在各个科的分布均匀性产生不同的影响。施氮使动物群落物种丰盛度分布均匀性略微降低。不同施氮水平对腐食性和杂食性类群的物种丰盛度分布均匀性影响最大,其次是寄生性和捕食性类群,对植食性类群的物种丰盛度分布均匀性影响最小。动物群落和腐食者的物种丰富度以及捕食者的物种丰富度和有效多样性(eH’)都与施氮水平呈二次抛物线回归关系;植食者物种丰富度和寄生者有效多样性(eH’)与施氮水平显著正相关,而植食者有效多样性(eH’)则呈负相关;但寄生者和杂食者的物种丰富度以及腐食者和杂食者的有效多样性(eH’)均与施氮水平无显著相关。动物群落有效多样性(eH’)与施氮水平呈三次方程曲线回归关系,呈现先下降(低、中施氮量)、后上升(高施氮量)、最后又下降(过高施氮量)的趋势。物种最多的8个目的物种丰富度和有效多样性(eH’)对不同施氮水平的响应也有很大不同。不同施氮水平只对半翅目、鳞翅目和蜘蛛目的物种丰富度以及半翅目和鞘翅目的有效多样性(eH’)有显著影响,且其影响比较复杂、而不同。动物个体总数以及植食者、捕食者和腐食者的丰盛度(个体数和生物量)均与施氮水平显著正相关,而动物总生物量和杂食者生物量与施氮水平呈二次抛物线回归关系,但寄生者丰盛度(个体数和生物量)和杂食者个体数与施氮水平无显著相关。不同施氮水平对8个主要目的丰盛度(个体数和生物量)的影响明显不同。不同施氮水平显著影响半翅目和同翅目的个体数和生物量、鳞翅目生物量以及鞘翅目、直翅目和蜘蛛目的个体数,但对鳞翅目个体数、膜翅目个体数和生物量以及鞘翅目、直翅目和蜘蛛目的生物量无显著影响。不同物种对施氮有不同的响应。黑翅粉虱、露尾甲和圆果大赤螨的个体数与施氮水平显著正相关;假眼小绿叶蝉、茶蚜、柑桔粉虱和日本管蛛的个体数与施氮水平呈二次抛物线的回归关系;恰里螺个体数与施氮水平呈三次方程S型曲线回归的关系,随施氮水平提高呈现先上升、后下降、最后又上升的趋势;但黄圆蚧、螟蛾科sp.1、吸螨sp.、草间小黑蛛、斜纹猫蛛、八斑球腹蛛、微蛛sp.1、白斑猎蛛、等节姚sp.和甲螨sp.的个体数与施氮水平无显著相关。动物群落均匀性与施氮水平呈三次方程曲线回归关系,随施氮水平提高呈现先下降(低、中施氮量)、后上升(高施氮量)、最后又下降(过高施氮量)的趋势。植食性类群均匀性随施氮水平提高而直线下降;捕食性类群均匀性与施氮水平呈二次抛物线回归关系,其均匀性随施氮水平提高微弱上升,在施氮水平过高时显著下降;寄生性类群均匀性随施氮水平提高而微弱提高;而腐食性和杂食性类群均匀性与施氮水平无显著相关。施氮对8个主要目的均匀性也产生不同的影响。不同施氮水平显著影响半翅目和同翅目昆虫的均匀性,但对鞘翅目、鳞翅目、膜翅目、直翅目、双翅目和蜘蛛目的均匀性无显著影响。动物群落稳定性评价指标S/N随施氮水平提高而显著降低;Sn/Sp和Sn/Sp′与施氮水平呈二次抛物线回归关系,Sn/Sp和Sn/Sp′随施氮水平提高显著上升,但在过高施氮水平时显著下降:Nn/Np和Nn/Np′与施氮水平呈三次方程曲线回归关系,随施氮水平提高呈现先显著下降、后上升、最后又下降的趋势。由此可见,不同施氮水平对动物群落稳定性的影响极其复杂,但过高施氮会造成动物群落稳定性下降。施氮造成茶园动物群落物种丰富度变化是茶树生产力(新梢生物量),全氮、氨基酸、咖啡碱、总糖和茶多酚的含量以及碳氮比和酚氨比的变化的综合作用的结果;施氮造成茶园动物群落物种多样性(eH’)变化是茶树生产力(新梢生物量),全氮、咖啡碱和茶多酚的含量以及碳氮比的变化的综合作用的结果。施氮造成茶园动物总个体数变化是茶树生产力(新梢生物量)及氨基酸和咖啡碱的含量变化综合作用的结果;施氮造成茶园动物总生物量变化是茶树生产力(新梢生物量)、全氮、氨基酸、咖啡碱和茶多酚的含量以及碳氮比的变化的综合作用的结果。茶园动物各营养类群的多样性和丰盛度以及18个重要物种的丰盛度对不同施氮水平也有不同的响应机制,其通常也是茶树生产力和多个生化指标综合作用的结果。研究结果证明,施氮对茶园生态系统的整个食物链产生深刻的影响。综上所述,同时考虑品种、营养、有害生物、天敌、产量和产品价值的相互作用,我们建立了武夷山茶叶收益(Y,RMB·ha-1·y-1)与施氮量(x,kg·ha-1·y-1)的关系模型Y=132,797+482.9079 x-0.3177 x2,武夷山市肉桂茶园的最适宜施氮量为760.01 kg·ha-1·y-1

【Abstract】 Nitrogen(N) and phosphorus(P) are the two most important limiting nutrients controlling the species composition,diversity,dynamicss,and functioning of terrestrial and aquatic ecosystems. The direct effects of fertilization on nutrient availability in ecosystems have been well studied, however little is known about the indirect effects of fertilization on herbivores or detritivores and subsequent changes imposed on community and ecosystem properties.To better understand animal community’s responses to fertilization and the underlying ecological mechanisms,we studied the effects of different fertilizers(organic fertilizer,PK,NPK and N) and nitrogen application rate(0,172.5,345.0,690.0,and 1035.0 kg N·ha-l·y-1) on tea plants and animal communities in tea plantations in Wuyishan,Fujian,China from August 2004 to December 2005. The relationships between the fertilizer-induced changes on productivity and chemical quality of tea plants and the composition,diversity and abundance of animal communities in the tea plantations were analyzed.The results are as follows:1.Effects of fertilizer application on tea productivity and physiologyNPK and N application significantly increased productivity(i.e.,young shoot biomass) and yield of tea plants.The effects were greater with NPK than N application.The increase by PK or organic fertilizer application was insignificant.Applications of NPK,N,PK or organic fertilizer significantly increased tissue nitrogen,and total and individual amino acids,while they decreased the tissue C/N ratio.The effects were greater with NPK or N than PK or organic fertilizer.NPK,N or PK significantly increased caffeine concentration,but not organic fertilizer.Either NPK or PK significantly increased content of total sugars with NPK more so than PK,but not when N or organic fertilizer was applied.NPK or N significantly decreased tea polyphenol content and polyphenol/amino acid ratio,but not with PK or organic fertilizer.2.Effects of N application on tea productivity and physiologyTea plants showed a moderate response to the N applications.The relationship between productivity or yield and the application rate was mostly quadric patterns,with the highest productivity and yield achieved at N application of 732.60 and 769.26 kg·ha-1·y-1,respectively.The tissue N,caffeine,total and individual amino acid contents significantly correlated,either with a quadratic or linear relationship,to the application rate.Excessive N usually produced no further increase,if not a decrease.Response of total or individual amino acids to the application rate varied with time and largely depended on the tissue N concentration.Polyphenol content and polyphenol/amino acid ratio decreased significantly with increasing N application.Total sugars showed a significant,cubic correlation with the application.Moderate N application tended to increase,while a high level application reduced the sugar content. Amino acids and total sugars in young and mature shoots,as well as caffeine in young shoots and C in mature shoots,significantly and positively correlated to the tissue N concentration.C/N and polyphenol/amino acid ratios in young and mature shoots;and nitrate N in young shoots and polyphenols in mature shoots significantly and negatively correlated to tissue N.However, caffeine in mature shoots showed a significant,quadric relationship with tissue N.There was no correlation between C content or polyphenols and tissue N concentration.N,amino acids,caffeine and total sugar contents in young and mature shoots were significantly and negatively related to the C/N ratio.Tea polyphenols in mature shoots and polyphenol/amino acid ratio in young and mature shoots significantly and positively correlated with the C/N ratio,but C concentration in young and mature shoots and polyphenols in young shoots showed no correlation with the C/N ratio.The results indicated that tissue N and the C/N ratio could reflect the tea chemical quality to a certain extent,but not C or polyphenols in young shoots.Therefore,it would be necessary to consider tissue N,C/N ratio and polyphenols in studying N-induced changes relating to the plant quality(e.g.,chemical composition) and herbivores.The results suggested that the seasonal tea productivity reduction associated with excessive N application was the result of the decreased amino acid metabolism in spring shoots,total sugar metabolism in summer shoots and amino acid and caffeine metabolism in autumn shoots.3.Composition,structure and diversity of animal community in tea plantationIn total,149,725 animals belonging to 3 phylums,8 classes,31 orders,252 families and 1,188 species were collected from the tea plantation.Among them,450 were herbivores(i.e.,37.88%of all species),323 predators(27.19%),133 parasitoids(11.20%),230 detritivores(19.36%) and 52 omnivores(4.38%).Homoptera,Sarcoptiformes,Stylommatophora and Coleoptera were ecological dominance groups,and Stylommatophora,Orthoptera and Lepidoptera were resource dominance groups in the community.The greatest majority(i.e.,98.99%) of the total animal species were occasional and rare species,and 90.91%unimportant resource species.The relationships between species and abundance for all animals,herbivores,predators, parasitoids and detritivores fitted both logarithmic normal distribution and logarithmic series distribution.On the other hand,for omnivores the relationship fitted only a logarithmic series distribution.Diversity,abundance and evenness of animal community and trophic groups showed evidence of a seasonal dynamics.Their diversity indexes significantly and positively correlated to the species richness and evenness.The animal community stability was significantly and positively related to diversity and evenness.Animal species richness increased in a power function with increasing sampling area,while animal abundance(i.e.,number of individuals and total biomass) showed a linear increase. Separately,animal species richness,number of individuals and total biomass positively correlated with mean animal species richness,individual number and total biomass in adjacent plots.The species richness of the animal community,herbivores,predators,detritivores or omnivores showed a significant power function correlation with the number of the individuals.So did the species richness of Hemiptera,Homoptera,Coleoptera,Lepidoptera,Hymenoptera,Diptera and Araneida.On the other hand,the species richness of parasitoids or Orthoptera increased significantly as the number of the individuals increased.The results suggested that the size of sampling area and spatial pattern could affect animal diversity and abundance,and that species richness of animal community,as well as trophic and order groups positively correlated with the number of individuals.Based on the ecological and resource dominance indexes,it was found that Kaliella depressa (Moellendorff),Aonidiella citrine(Coquillet),Empoasca vitis Gothe,Toxoptera aurantii Boyer, Aleurocanthus spiniferus Quaintance,Carpophilus obsoletus Erichson,Dialeurodes citri Ashm, Pyralididae sp.1,Buzura suppressaria Guenee,Brddybaena similaris(Ferussac) and Xenocatantops brachycerus(Willenmse) were important animal pests in tea plantations;Anystis baccarum Linnaeus,Trachelas japonicus Boesenberg et Strand,Erigonidium graminicolum(Sun de Vall),Bdellidae sp.,Evarcha albaria(L.Koch),Ducetiajaponica Thunberg,Anotogaster sp., Sphedanolestes impressicollis St(?)l,Orius similis Zheng,Oxyopes sertatus L.Koch and Misumenops tricuspidatus(Fabricius) were important natural enemies;and,Oribatida sp.1 and Isotomidae sp.1 were dominant species of detritivores.However,there was no dominant species of parasitoids and omnivores.4.Animal species diversity,abundance and body size relationshipsThe empirical relationships among body size,species richness and number of individuals might give insight into the factors controlling species diversity and the relative abundances of species. Among total animals,trophic groups and the 8 most abundant taxonomic orders(i.e.,Hemiptera, Homoptera,Coleoptera,Lepidoptera,Hymenoptera,Orthoptera,Diptera and Araneida),species richness and numbers of individuals were related to body sizes as unimodal diversity patterns. However,the peak sizes,number of species and number of individuals differed among the groups. Species richness peaked with intermediate body sizes for all animals or individual groups.It was the same on the number of individuals for predators,parasitoids,omnivores and abundant taxonomic orders(except Homoptera).However,the number of individuals peaked with small body sizes for all animals,herbivores,detritivores and Homoptera.Body size of a species depended on the species’ evolutionary history(taxonomic order),trophic role(contemporary trophic group) and interaction of the two factors.Species richness(Si) within a size class related to the number of individuals(Ii) as Si=1.511 Ii0.436.For the majority of the trophic groups(except herbivores) and taxonomic orders(except Homoptera),the correlations were of similar power functions.However,for herbivores or Homoptera the correlations belonged to more complicated power functions.Only a part of predators(i.e.,26%) was larger than their preys.Number of individuals or biomass) of most predators was less or smaller than their prey.Body mass,number of individuals or biomass of predators significantly and positively correlated to those of their preys.5.Effects of fertilizer application on animal communities and underlying ecological mechanismsApplication of organic fertilizer or PK increased,but that of NPK or N decreased species distribution evenness among orders for animal communities.Organic fertilizer,PK,NPK or N increased species abundance evenness for animal communities,and the effect of organic fertilizer or PK was greater than that of the others.Different fertilizers differed on their effect on species distribution evenness among orders,the species abundance evenness for each trophic group,as well as the species distribution evenness among families for the 8 most abundant orders.N and NPK significantly increased animal species richness.Organic fertilizer,N and PK significantly increased animal diversity.However,organic fertilizer and PK showed no effect on animal species richness,nor did NPK on animal diversity.Organic fertilizer significantly increased effective diversity of herbivores,while it decreased species richness of detritivores.N application significantly increased species richness of detritivores.However,no fertilizers showed any effect on other diversity indices for trophic groups.Organic fertilizer significantly decreased species richness of Hemiptera insects.N and NPK applications significantly increased effective diversity of Homoptera insects.However,all 4 fertilizers showed no effect on other diversity indices within orders.Applications of organic fertilizer and PK significantly decreased the number of individuals for all animals.NPK significantly increased total animal biomass.But,the effects of N and NPK on number of all animals and those of organic fertilizer,and PK and N on total animal biomass were not significant.Organic fertilizer significantly decreased numbers of herbivores,predators and omnivores,as well as detritivore biomass.NPK significantly increased herbivore biomass,and decreased numbers of predators and detritivores.PK significantly decreased number of predators and detritivores.However,all 4 fertilizers showed no effect on other abundance indices for trophic groups.The results showed that organic fertilizer or PK benefited the control of animal pests(esp. Homoptera pests);number of predators decreased as the numbers of herbivores and detritivores decreased;and,moderate N fertilization did not significantly increase the number of animal pests. Responses of individual animals to fertilization varied according to the application.Fertilizer application had different and significant effects on 10 of the 18 abundant animals(i.e.,8 most abundant herbivores,8 most abundant predators and 2 most abundant detritivores).Organic fertilizer and PK significantly increased animal community evenness.But,the effects of NPK and N were not significant.Organic fertilizer application significantly increased herbivore evenness.Organic fertilizer,PK and N significantly increased the evenness of Lepidoptera insects. However,the effects of different fertilizers on other trophic groups and orders were not significant. Organic fertilizer and PK increased animal community stability through increasing S/N,but not NPK or N. Fertilizer-induced changes in animal species richness in tea plantations depended on the integrated actions of plant productivity,and the contents of total sugars and polyphenols of tea plants.But the changes in number of animals depended on the integrated actions of plant productivity,and the contents of amino acids and total sugars of tea plants.Responses of species richness and abundance of trophic groups,as well as the abundance of 18 abundant animals,to fertilization varied with fertilizer-induced changes in plant productivity and chemical quality tea plants,through different mechanisms,which also often depended on the integrated actions of the productivity and chemicals of tea plants.This study demonstrated that short-term fertilizer application affected the entire food chain in the tea plantation ecosystem.6.Effects of N application on animal communities and underlying ecological mechanismsN application reduced species distribution evenness among orders for animal communities, predators and detritivores,while increasing it for herbivores.Different N application rates had different effects on species evenness distribution among families for the 8 most abundant orders. N slightly reduced species abundance evenness for the animal community.It had the greatest effect on species abundance evenness for detritivores.The effects for parasitoid and predators were greater than herbivores.Species richness of all animals and detritivores,as well as predator species richness and effective diversity,significantly correlated in quadratic functons with N application rate.Effective animal diversity showed a cubic relationship with the application rate.However,there was variation in trophic responses to N,species richness of herbivores and effective diversity of parasitoids increased as N increased,while effective diversity of herbivores decreased.But,the species richness of parasitoids and omnivores,as well as effective diversity of detritivores and omnivores,showed no responses to the N application.For the 8 most abundant orders,only N had a complicated and different effect on the species richness of Hemiptera,Lepidoptera and Araneida groups,as well as the effective diversity of Hemiptera and Coleoptera groups.Number of all animals and the abundance(i.e.,number of individuals,biomass) of herbivores, predators and detritivores were significantly and positively related to the rate of N application. Biomass of all animals and omnivores significantly correlated with N application rate in quadratic equations.But,parasitoid abundance(i.e.,number of individuals,biomass) and number of omnivores showed no responses to the application.For the 8 most abundant orders,N had a complicated and different effect on the abundance(i.e.,number of individuals,biomass) of Hemiptera and Homoptera insects,as well as biomass of Lepidoptera insect and number of Coleoptera,Orthoptera and Araneida arthropods.Responses of individual animals to the fertilization varied with N gradient.N had different and significant effects on 8 of the 18 abundant animals. Animal community evenness showed a cubic correlation with N application.Herbivore evenness increased as N increased;predator evenness showed a quadratic relationship with the N application,excessive N reduced the evenness;parasitoid evenness slightly increased with N increasing;and,evenness of detritivores and omnivores were not affected.Responses of the 8 most abundant orders to N fertilization varied with N gradient.It only affected the evenness of Hemiptera and Homoptera insects.Animal community stability index,S/N,decreased as N was increased,Sn/Sp(ratio of natural enemy species richness to animal pest species richness) and Sn/Sp’(ratio of natural enemy species richness to prey species richness) showed quadratic relationships,and Nn/Np(ratio of natural enemy number to animal pest number) and Nn/Np’(ratio of natural enemy number to prey number) showed cubic relationships with the rate of N application.This suggested that the effect of N on animal community stability was very complicated,and that N overuse could reduce it.N-induced changes in animal species richness in tea plantations depended on the integrated actions of plant productivity,the contents of tissue N,amino acids,caffeine,total sugars and polyphenols,and C/N ratio and polyphenol/amino acid ratio of tea plants.But the changes in effective animal diversity depended on the integrated actions of plant productivity,the contents of tissue N,caffeine and polyphenols,and C/N ratio of tea plants.N-induced changes in the number of all animals depended on the integrated actions of plant productivity,and amino acids and caffeine concentrations.But the changes in total animal biomass depended on the integrated actions of plant productivity,the contents of tissue N,amino acids,caffeine and polyphenols,and C/N ratio of tea plants.Responses of trophic group diversity(i.e.,species richness and effective diversity),as well as the abundance of trophic groups and 18 abundant animals,to N application varied with N-induced changes in plant productivity and chemical quality through different mechanisms,which also often depended on the integrated actions of the productivity and chemicals of tea plants.This study demonstrated that short-term N application affected the entire food chain in the tea plantation ecosystem.Better understanding of the interactions of varieties,nutrients,pests,yield and production costs involving the tea plantation will allow an improved integration of the pest and nutrient management to maximize benefits for the farmers and producers.A mathematic model for calculating tea production profit and N application was established as follows: Y=132,797+482.9079x-0.3177x2,where Y= profit in RMB·ha-1·y-1,and x= N in kg·ha-1·y-1.It suggests that the optimum rate of nitrogen application would be 760.01 kg·ha-1·y-1 for Wuyishan Rougui oolong tea plantations.

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