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1.
以分布在太白山国家森林公园3个海拔高度的游击型克隆植物独叶草为研究对象,分析测定了不同分株营养器官中C、N、P、K和Mg含量.结果表明:分株年龄、海拔梯度以及分株年龄与海拔梯度的交互作用对独叶草分株各营养器官全碳含量的影响不显著(P>0.05),对全氮、全磷、K和Mg含量的影响程度各不相同,说明独叶草无性系分株通过自身的生理代谢调整了各器官中营养元素的分配.在高海拔生境中,分株年龄显著影响独叶草无性系分株各器官的K含量、根状茎和根中的全氮含量(P<0.05).除了中海拔(2 800~2 900 m) 独叶草无性系分株的K与全氮、全磷和Mg含量相关性不明显外,其他海拔各元素两两间均呈显著相关(P<0.05).这表明高海拔生境中生理可塑性对克隆植物生长的贡献可能比低海拔更大,强的生理可塑性有助于克隆植物在高山环境中有效地利用资源,实现种群扩展、开拓新的生境.这也可能是独叶草在长期演化过程中对异质生境的一种生理响应.  相似文献   

2.
Addis EA  Davis JE  Miner BE  Wingfield JC 《Oecologia》2011,167(2):369-378
Organisms frequently need to adjust physiological mechanisms to successfully breed in novel habitats. To explore how some populations physiologically acclimate to novel environmental conditions while others do not, we examine three subspecies of the white-crowned sparrow, Zonotrichia leucophrys. Of these subspecies, Z. l. pugetensis has expanded its breeding range to high altitude over the last 60 years. We investigate physiological acclimation to high altitude conditions by comparing circulating levels of glucocorticoids among Z. l. gambelii, which only breeds at high altitude, Z. l. nuttalli, which only breeds at low altitude, a population of Z. l. pugetensis that breeds at low altitude, and a Z. l. pugetensis population that now breeds at high altitude. Glucocorticoids mediate physiological and behavioral responses to environmental conditions and are constitutively secreted, but can also be released facultatively. We hypothesized that elevation of the glucocorticoid corticosterone (CORT) may facilitate breeding in high altitude environments. We tested this hypothesis by comparing baseline and stress-induced CORT levels of subspecies breeding at low altitude, Z. l. pugetensis and Z. l. nuttalli, to subspecies breeding at high altitude, Z. l. pugetensis and Z. l. gambelii. We found that populations breeding at high altitude exhibit higher baseline and stress-induced levels of CORT. Additionally, we found that Z. l. pugetensis exhibit greater variation in the stress-induced CORT response. These results suggest an importance of modulation of hormonal mechanisms in facilitating breeding in high altitude environments, and that variation in these mechanisms may be associated with facilitating altitudinal range expansion.  相似文献   

3.
High Altitude Adaptation in Mammals   总被引:1,自引:0,他引:1  
The physiological, morphological, and biochemical characteristicsof several species of mammals resident at high altitude arecompared with those of their sea level counterparts. The differencesnoted in these characteristics are in a direction that facilitatesthe acclimatization of those living at high altitude. The differencesamong species point to the fact that the mechanism of adaptationto altitude (i.e., hypoxia) is still not understood. This reviewemphasizes that the adaptive process is complex and made upof several components, that these components are inter-related,and that neither the physiological nor morphological adaptationscan fully account for the tolerance to hypoxia. Although onlysuperficially studied as yet, the biochemical adaptations appearmost important.  相似文献   

4.
High altitude acclimatization is a series of physiological responses taking places when subjects go to altitude. Many factors could influence these processes, such as altitude, ascending speed and individual characteristics. In this study, based on a repeated measurement design of three sequential measurements at baseline, acute phase and chronic phase, we evaluated the effect of BMI, smoking and drinking on a number of physiological responses in high altitude acclimatization by using mixed model and partial least square path model on a sample of 755 Han Chinese young males. We found that subjects with higher BMI responses were reluctant to hypoxia. The effect of smoking was not significant at acute phase. But at chronic phase, red blood cell volume increased less while respiratory function increased more for smoking subjects compared with nonsmokers. For drinking subjects, red blood cell volume increased less than nondrinkers at both acute and chronic phases, while blood pressures increased more than nondrinkers at acute phase and respiratory function, red blood cell volume and oxygen saturation increased more than nondrinkers at chronic phase. The heavy and long-term effect of smoking, drinking and other factors in high altitude acclimatization needed to be further studied.  相似文献   

5.
Age as a cause of chronic mountain sickness (Monge's disease)   总被引:3,自引:0,他引:3  
Chronic mountain sickness (CMS) or Monge's disease is a clinical entity observed among residents at altitude characterized by polycythaemia increased above the physiological level due to altitude adaptation. From correlation studies of haematocrit with ventilation rate of healthy and diseased native high altitude residents (4,540 m) it was found that CMS is a clinical manifestation of aging. The higher the altitude the sooner the symptoms of excessive polycythaemia will become evident.  相似文献   

6.
高原地区动物面临一系列严峻的生存考验,随着海拔的变化,动物栖息地的食物资源等差异大,温度、氧分压等环境因子都将发生变化.环境差异可能会影响动物种群的生活史对策.在生理功能适应中,动物的能量代谢适应扮演着重要的角色.为探究高原鼠兔(Ochotona curzoniae)在不同海拔地区的能量代谢适应与热中性区范围,分别选取...  相似文献   

7.
Pilots' physiological measurement in conditions of alternating plus and minus Gz (gravitational acceleration) has been done during real flights. The comparison of physiological responses during flights at the safe altitude of 7000 ft and low level flights at the altitude of 900 ft over ground bears on the evaluation of changes of the continuous blood pressure and the heart rate. High level of pilots' plus-minus Gz tolerance is essential requirement to cope with low level flights in agile aircraft. It was proved that the sinusoidal profile during real flights is possible to use for pilots' tolerance to plus and minus Gz load evaluation. A system for the physiological signal acquisition in a cockpit of combat aircraft was developed for this purpose.  相似文献   

8.
To understand the morphological and physiological variations among the temporary and permanent residents of high altitude, this study was undertaken at Leh, Ladakh. It is situated at 3500 m (11500 feet) above sea level, the mean barometric pressure was 500 tors and air temperature varied from 2 degrees C to 20 degrees C. The highland Tibetans showed broadest chest and most developed musculature closely followed by Ladakhi Bods. These high altude natives also displayed significantly higher value of vital capacity, forced vital capacity, and inspiratory capacity. The better respiratory efficiency observed among high altitude residents indicates higher degree of adaptation to high altitude hypoxia. Temporary residents were observed to be tallest and fattest with lower trunk fat predominance of all the four groups and showed narrowest chest and lower respiratory efficiency as compared to high altitude natives. The duration of stay at high altitude has clearly brought about a perceptible difference in body dimensions and respiratory functions of various groups of adult males studied at same altitude.  相似文献   

9.
研究了纳帕海高原湿地4种常见的多年生水生植物经移栽至不同海拔后,在生长过程中的生长状况、叶绿素、可溶性糖、游离脯氨酸(Pro)含量、过氧化物酶(POD)活性的变化及其生理特性。结果表明,水葱(Scirpusvalidus)、荸荠(Heleocharis dulcis)、黑三棱(Sparganium stoloniferum)和茭草(Zizania latifolia)的生长状况随着海拔的降低均有所改善,其中,4种湿地植物的株高随海拔的降低均有所升高,水葱和荸荠的茎粗随海拔的降低均呈现增粗的趋势,黑三棱和茭草的叶片宽度也随海拔的降低有所增加;4种湿地植物的叶绿素(a+b)含量随着海拔的降低均呈现不断下降的趋势;4种植物的可溶性糖和游离脯氨酸(Pro)含量随海拔的降低均有所下降;荸荠、黑三棱和茭草的过氧化物酶(POD)活性随海拔的降低均呈下降趋势,而水葱的过氧化物酶(POD)活性随着海拔的降低无显著变化,黑三棱和茭草的过氧化物酶(POD)活性显著高于其它两种植物。可见,4种湿地植物的形态、生理特征对不同海拔生境的适应方式可能是通过多种途径实现的,如形态特征、光合作用、抗寒物质代谢、抗氧化酶系统等随海拔梯度的变化而变化。这些不同的适应方式在不同的植物间既有共同规律,又有着各自的特性。  相似文献   

10.
High-altitude areas are important socio-economical habitats with ruminants serving as a major source of food and commodities for humans. Living at high altitude, however, is extremely challenging, predominantly due to the exposure to hypoxic conditions, but also because of cold temperatures and limited feed for livestock. To survive in high-altitude environments over the long term, ruminants have evolved adaptation strategies, e.g. physiological and morphological modifications, which allow them to cope with these harsh conditions. Identification of such selection signatures in ruminants may contribute to more informed breeding decisions, and thus improved productivity. Moreover, studying the genetic background of altitude adaptation in ruminants provides insights into a common molecular basis across species and thus a better understanding of the physiological basis of this adaptation. In this paper, we review the major effects of high altitude on the mammalian body and highlight some of the most important short-term (coping) and genetically evolved (adaptation) physiological modifications. We then discuss the genetic architecture of altitude adaptation and target genes that show evidence of being under selection based on recent studies in various species, with a focus on ruminants. The yak is presented as an interesting native species that has adapted to the high-altitude regions of Tibet. Finally, we conclude with implications and challenges of selection signature studies on altitude adaptation in general. We found that the number of studies on genetic mechanisms that enable altitude adaptation in ruminants is growing, with a strong focus on identifying selection signatures, and hypothesise that the investigation of genetic data from multiple species and regions will contribute greatly to the understanding of the genetic basis of altitude adaptation.  相似文献   

11.
Adult male toads were exposed to simulated high altitude of 24,000 feet for 96 hrs of continuous exposure in a decompression chamber. The animals were sacrificed immediately after the exposure period. Significant increase of the weight of the ventricle and spleen is observed in altitude exposed animals. Red blood cell, hemoglobin concentration, hematocrit ratio and red cell mass are significantly increased in high altitude exposed animals in comparison to control. MCV (mean corpuscular volume) and MCH (mean corpuscular hemoglobin) are decreased in altitude exposed group. Plasma volume, blood volume, extracellular fluid volume, intracellular fluid volume and total body water are decreased significantly after altitude exposure for 96 hrs. These physiological changes are thought to be due to dehydration of this animal at simulated high altitude and it is highly affected after 96 hrs of exposure as evidenced by the significant reduction of total body water and intracellular fluid volume.  相似文献   

12.
Aerobic physiology at high altitudes has been studied in many animals. Prior work on laboratory-bred deer mice (a species with a wide altitudinal range) showed depression of aerobic capacity at high altitude, even after acclimation. However, wild deer mice show no reduction in thermogenic performance at high altitude, and performance limits seem to be due to physiological and anatomical adjustments to environmental temperature and not to oxygen availability. We asked whether across-altitude performance differences exist in deer mice after accounting for temperature acclimation (approximately 5 degrees and 20 degrees -25 degrees C) and prenatal and neonatal development altitude (340 vs. 3,800 m). We measured maximal thermogenic oxygen consumption (VO2sum) in cold exposure and ran mice on a treadmill to elicit maximal exercise oxygen consumption (VO2max). We found a 10% reduction in VO2max at 3,800 m compared with that at 340 m; thus, the mice were able to compensate for most of the 37% reduction in oxygen availability at the higher altitude. Development altitude did not affect VO2max. There was no effect of test altitude or development altitude on VO2sum in warm-acclimated animals, but both test and development altitude strongly affected VO2sum in cold-acclimated mice, and compensation for hypoxia at 3,800 m was considerably less than that for exercise.  相似文献   

13.
Resveratrol, as a natural polyphenolic compound, has a wide range of beneficial effects, which includes anti-tumor, cardiovascular protection, anti-oxidant and estrogen-like effects, and so on. Its various physiological properties are closely related to the therapeutic principle for prevention and treatment of high altitude hypoxia injury. Resveratrol may play an important role in relieving or curing high altitude diseases, especially high altitude polycythemia(HAPC). However, the literature about study and application of resveratrol in plateau medicine field is rarely reported up to now. In this review, we summarized the physiological effects of resveratrol, discussed the possible main principle of resveratrol for HAPC therapy, and looked forward to resveratrol's perspective or potential application in high altitude medicine.  相似文献   

14.
以云南高黎贡山百花岭不同海拔梯度(1500~3100 m)的短肋羽藓(Thuidium kanedae)为材料,通过测定其叶绿素含量和实际光合量子产量,研究其光合特性随海拔梯度变化的规律。结果表明,短肋羽藓的实际光合量子产量Y(Ⅱ)与叶绿素总量、叶绿素a、叶绿素b含量及叶绿素a/b比值之间都呈负相关关系。随着海拔升高,其叶绿素总含量、叶绿素a及叶绿素b含量都呈先升高而后下降的“单峰”分布模式,但随着海拔进一步升高,叶绿素总含量及叶绿素a含量变化不明显,而叶绿素b含量呈现明显上升趋势。叶绿素a/b比值随着海拔升高先呈现“单峰”分布模式,然后随着海拔继续升高呈现缓慢下降的趋势。实际光合量子产量Y(Ⅱ)整体表现出随海拔升高而增加的趋势,并在高海拔处出现急剧上升的趋势。本研究为揭示苔藓植物在不同海拔梯度下适应生态环境的生理机制提供参考。  相似文献   

15.
在海拔2300m选择健康成年男性5人,急进抵海拔4660m,用多导监测仪分别在两地连续7h监测夜间睡眠、呼吸状态和血氧饱和度变化,进行自身对比。结果发现:(1)急进高海拔后,总睡眠时间、有效睡眠指数、Ⅲ~Ⅳ期深睡眠均较中度高原减少(p<0.01);总觉醒时间、Ⅰ~Ⅱ期浅睡眠高海拔较中度高原增多(p<0.05):(2)急进高海拔后,有3名健康人出现周期性呼吸,其中1名健康者出现周期性呼吸119次,伴有中枢性睡眠呼吸暂停,最低Sao_2为78%;(3)同海拔高度夜间睡眠时与清醒时Sao_2相比较,中度高原下降4.2%,高海拔下降11.2%(p<0.01);高海拔与中度高原夜间清醒时Sao_2相比较下降7.4%,睡眠时下降14.4%(p<0.001)。结果提示:(1)睡眠加重了高原人原有的低氧血症;(2)低氧血症导致睡眠结构的紊乱和睡眠质量的降低;(3)睡眠中出现的周期性呼吸,应视为机体的一种自我保护机制;(4)频发的周期性呼吸或睡眠呼吸暂停将影响大脑机能。  相似文献   

16.
通过分析庞泉沟国家级自然保护区不同海拔(1 600~2 800 m)梯度华北落叶松针叶中3种抗氧化酶及光合色素含量的变化,探讨了高山林木适应环境的生理机制.结果表明,华北落叶松针叶中超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性随海拔梯度的变化规律相一致,即中海拔区(1 900~2 400 m)的3种抗氧化酶活性相对较低,而低海拔区(1 600~1 800 m)和高海拔区(2 500~2 800 m)活性相对较高.低海拔区3种酶活性分别比中海拔区提高62.79%、42.13% 和 7.87%,高海拔区分别提高75.20%、14.49% 和 63.38%,但临近森林垂直分布上限活性降低.膜脂过氧化产物丙二醛含量在低海拔区和高海拔区分别达9.27和14.06 μmol·g-1 FM,而在中海拔区平均含量为5.58 μmol·g-1 FM.叶绿素和类胡萝卜素含量随海拔梯度升高而降低,相关系数分别为-0.969和-0.986;但叶绿素a/b比值及Car的相对含量(Car/Chl)随海拔梯度升高而增加,相关系数分别为0.962和0.877.  相似文献   

17.
18.
Evidence is presented that Strophingia ericae , a small homopteran feeding on Calluna has two physiological races. One of these occurs from sea level up to about 200 m altitude, and the other above this altitude.  相似文献   

19.
The purpose of this study was to examine the resting and exercise response patterns of plasma Peptide F immunoreactivity (ir) to altitude exposure (4300 m) and caffeine ingestion (4 mg.kg b.w.-1). Nine healthy male subjects performed exercise tests to exhaustion (80-85% VO2max) at sea level (50 m), during an acute altitude exposure (1 hr, hypobaric chamber, 4300 m) and after a chronic (17-day sojourn, 4300 m) altitude exposure. Using a randomized, double-blind/placebo experimental design, a placebo or caffeine drink was ingested 1 hour prior to exercise. Exercise (without caffeine) significantly (p less than 0.05) increased plasma Peptide F ir values during exercise at chronic altitude only. Caffeine ingestion significantly increased plasma Peptide F ir concentrations during exercise and in the postexercise period at sea level. Conversely caffeine ingestion at altitude resulted in significant reductions in the postexercise plasma Peptide F ir values. The results of this study demonstrate that the exercise and recovery response patterns of plasma Peptide F ir may be significantly altered by altitude exposure and caffeine ingestion. These data support further study examining relationships between Peptide F (and other enkephalin-containing polypeptides) and epinephrine release in response to these types of physiological stresses.  相似文献   

20.
长白山暗针叶林苔藓植物生物量的研究   总被引:9,自引:0,他引:9  
在长白山北坡暗针叶林对地面和树附生苔藓植物的生物量进行了测定.地面生苔藓采取样带调查取样法测定,树附生苔藓应用McCune方法对树干和树枝的附生苔藓生物量都做了细致的测定.结果表明,长白山暗针叶林中的苔藓植物分布很不均匀,随海拔变化差异很大,海拔1100m最低,仅为543kg·hm^-2;海拔1250m最高,达5097kg·hm^-2.苔藓植物生物量的变化对生境有很好的指示作用,特别是塔藓和拟垂枝藓的生物量随海拔的变化与森林系统的群落学特点有一定的相关性:在海拔1100~1700m,塔藓的生物量与臭冷杉的重要值变化趋势相近,随海拔升高而减少;拟垂枝藓的生物量与鱼鳞云杉重要值的变化趋势相似,随海拔升高而增加.此外,生物量随海拔的变化表明了不同苔藓植物对环境条件要求的差异,拟垂枝藓比塔藓水分条件要求更高.因此,生物量的研究在植物生理上也有一定的指示作用.  相似文献   

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