Response of Pinus koraiensis seedling growth to different light conditions based on the assessment of photosynthesis in current and one-year-old needles

As one of the three major five-leaved pines in the northern hemisphere, Pinus koraiensis is the most important dominant tree species in the natural mixed-broadleaved Korean pine forests. However, the regeneration of P koraiensis under the canopy of secondary forest stands is poor because of the light limitation. This study was conducted to understand how P koraiensis seedlings adapt to different light intensities and what would be the optimum light level for their establishment and growth. Three repetition plots with four light intensities （15%, 30%, 60% and 100% of the natural incident irradiances, achieved by suspending layers of black nylon net above and surrounding the plots） were set up under natural climate conditions in a montane region in eastern Liaoning Province, Northeast China. A total of 80 P koraiensis seedlings with similar height and root collar diameter were transplanted into four plots. After one year of acclimation to the specific light conditions, the seasonal variations of the photosynthetic variables and needle traits of the current and one-year-old needles, and the growth parameters were observed under four light intensities. The results indicated that： （1） The seedling at 60% treatment exhibited the greatest growth, which agreed with the response of the light-saturated photosynthetic rates （Amax） and the dark respiration rate （Rd） in the current and one-year-old needles, i.e., Rd at 60% treatment was significantly lower than that at 100% treatment, but Amax did not differ between the seedlings at 100% and 60% treatments. （2） The P. koraiensis seedlings have a certain photosynthetic plasticity to adapt the light conditions by adjusting their needle traits and regulating the physiological processes, because Amax, Rd, light saturation point and compensation point, the needle mass area, needle nitrogen and chlorophyll contents were significantly （p〈0.05） correlated with the light intensities. Especially, Am,x at 100% and 60% treatments was significantly higher （p〈0.05） than that at 30% and 15% treatments for both current and one-year-old needles. （3） The needles of different ages played a commutative role during the growing season, i.e., the one-year-old needles played a major role for the photosynthesis in the early growing season; the current year needles did in the later growing season. This ensured the effective photosynthesis throughout the growing season. These findings suggest that P. koraiensis is the in-between heliophilous and shade-tolerant tree species at least for the seedlings up to 8 years.     

奶牛患病的注射疗法

1皮下及皮内注射皮下注射是将药液经皮肤注入皮下疏松组织内的给药方法,适用于药量少、刺激性不大的药液。注射部位以皮肤较薄、皮下组织疏松处为宜。奶牛一般在颈侧,如药液量过多时,可分数处将药液注入皮下,部位还可选在肘及肩后皮肤较薄处。皮下注射一般使用16号针头。具体是在注射部位剪毛消毒(用     

浅谈常见猪病的临床注射方法

在实际临床中,对猪病的治疗需要注射不同的部位,笔者根据多年的临床经验,作如下的介绍。1注射前的准备（1）按猪的大小、肥瘦、注射种类、药量,选择适宜的注射器及针头,以及消毒药和所需用品。（2）检查注射器是否有破损,金属注射器橡皮垫是否密封,松紧度调节是否合适,针头是否堵塞、锐利、与针管的结合是否严密。     

一起山羊附红细胞体病的诊治报告

附红细胞体病是由附红细胞体寄生于动物红细胞和血浆中而引起的一种传染病,主要引起动物高热、贫血、黄疸和全身发红,腹部皮下和四肢末梢发紫,且多为隐性感染。猪、绵羊、牛、马、犬、猫和其它动物易感并有较多报道,山羊感染此病的报道不多。该病主要由吸血昆虫(如蚊、跳蚤、虱     

高压树干注射关键技术研究

树干注射是一种通过向树干注射药剂防治病虫害、矫治缺素症和调节树木生长的技术。树干注射技术涉及注射和传导机理、药剂和制剂、残留和伤害等诸多问题。在对国内外3种类型树木注射施药技术特点分析的基础上,对注射压力、内吸剂药液的筛选、注射针头、药剂传导、密封以及伤口等高压树干注射关键技术进行了研究,探讨树干注射理论、药剂研发和机具研究的发展方向。     

最美国家电网人——记文登市电业总公司“三八红旗手”吕明玉

她,一名普通的电网女工。她,一名从来不敢看注射针头的女人,却在8年前开始参加无偿献血。她,一名5岁女儿的母亲,用爱心为一个33岁的陌生生命奏响了生命续曲。她就是山东省文登市电业总公司的职工吕明玉,1991年进入文登市电业总公司,20年来受公司企业文化的熏陶,养成了她工作积极、心地善良、无私奉献的品格。亲人们对她的     

美国Pulse无针头注射系统

近年来无名高热病、蓝耳病等传染性疾病的流行给猪场主沉重的打击,所以加强免疫普及是很重要的。一头猪按照标准免疫程序一生至少要注射25次疫苗,每一次注射需一次性注射器及一次性针头一套,有的小规模的猪场使用后直接随地扔掉,随     

牛耳静脉输液方法初探

牛是主要的经济家畜和役用家畜。牛病治疗在生产实际中是必不可少的,静脉输液是治疗牛病最主要的且经常使用的治疗方法。当前对牛静脉输液都是采用颈静脉输液的方法,这种输液方法笔者在多年的兽医临床实践中发现存在有许多弊端:首先牛颈部皮较厚,术者需用较大的力,这样对牛刺激大,牛易躁动,进针困难,且对人、畜都不安全。在进针后针头不易固定,稍一动,针头就会移出血管外,使输液无法进行。在牛颈静脉处扎针时,术者需弯腰或下蹲,十分不便。     

治疗猪病巧用水

<正>治疗僵猪。猪耳根后部偏下方凹陷处,左右侧各有1个穴。根据实际情况选择生理盐水、注射用水、维生素B注射液、5%~25%葡萄糖注射液等。方法是选兽用12号注射针头,取上述药物5~15 mL,注入左右侧穴位,1次/d,一般12~24 h即可见效。治疗肩胛、腰、颈、四肢等部位僵硬。猪患部肌肉肿胀、发硬者,可采用热敷疗法,用热水加少许盐和醋,热敷猪患部。准备酒、醋各1 kg,把适量棉花放于患部,再把醋烧热,放于酒中,然后倒在棉花上热敷,1次/d。也可用醋炒酒糟,炒到烫手时装入麻袋,     

家禽打针七注意

一、腿部打针不要打内侧因为家禽腿上的主要血管神经都在内侧,在这个部位打针易造成血管、神经的损伤,出现针眼出血、瘸腿、瘫痪等症状。二、皮下注射不要用粗针头用粗针头皮下注射因深度浅、针眼大,注入药液后易流出,易引起发炎流血。皮下注射特别是给仔禽注射要用细针