台灣三種草蜥之溫度生理及海拔分布之關係

dc.contributor杜銘章zh_TW
dc.contributorMing-Chung Tuen_US
dc.contributor.author黃淑萍zh_TW
dc.contributor.authorShu-Ping Huangen_US
dc.date.accessioned2019-09-05T06:16:01Z
dc.date.available2009-1-1
dc.date.available2019-09-05T06:16:01Z
dc.date.issued2008
dc.description.abstract生物的地理分布範圍可能受到其地理屏障、生物性交互作用 (例如:競爭、寄生、疾病等) 以及非生物環境適合性 (environmental suitability) (例如溫度、溼度、光線因子等) 的共同影響。雖然環境因子是影響生物地理分布的重要因素,其和生物性因子的相對影響程度卻不容易釐清。深入了解那些環境因子影響野生動物的地理分布範圍以及其影響的機制不僅是生態學及演化生物學的重要議題,在我們未來評估環境變遷對其地理分布的衝擊以及對其經營管理也有重要參考價值。 本研究以三種分布在台灣不同海拔範圍的草蜥屬蜥蜴為題,探討環境因子對其海拔區隔分布所扮演的角色。牠們分別是雪山草蜥 (T. hsuehshanensis,海拔分布 > 1800m) 、台灣草蜥 (T. formosanus,海拔分布< 1500m) (後改名為翠斑草蜥,T. viridipunctatus) 以及蓬萊草蜥 (T. stejnegeri,海拔分布 < 1000m) 。本研究分成兩部分 : 在第一部分,我推測環境溫度可能是造成這些草蜥海拔區隔分布的重要因子。我測量這三種草蜥的高溫耐受度、低溫耐受度及衝刺速度等與生存相關的重要生理特徵,以了解牠們對溫度的耐受範圍以及其具備優良運動表現時的體溫範圍。經由比較物種間生理特徵的差異性以及對照高、低海拔地區野外環境的溫度範圍,我進一步推測環境溫度對這些草蜥的海拔分布範圍的影響程度,這部分研究將分別於第一章至第三章介紹。在第二部分,我針對雪山草蜥進行移地圈養實驗,將其圈養在低海拔地區野外環境下,觀察其生存及生長情形,以推測環境因子對其海拔分布的影響程度,這將於第四章介紹。 在第一章,我研究雪山草蜥對高溫的耐受能力是否是造成其無法分布於低海拔環境的主要生理限制因子。我測量牠的臨界高溫值 (critical thermal maximum) 以及其在三種溫度處理下三個月的存活率。台灣草蜥及蓬萊草蜥則為作為對照組。這三種處理分別為為極高溫組、高溫組及低溫組。其中,極高溫處理及高溫處理是分別將其每日最高溫度設定為低海拔地區夏季時的歷史極高溫以及每日高溫的平均值,日夜溫度變動範圍則設為7-10oC,而低溫處理則設定為相當於高海拔地區的夏季氣溫。結果顯示: (一) 雪山草蜥的臨界高溫值高於低海拔地區的歷史高溫,並且與另兩種草蜥的臨界高溫值沒有顯著差異,(二) 雪山草蜥能在極高溫處理及高溫處理下存活,且其存活率與另兩種草蜥的存活率沒有顯著差異。因此,雪山草蜥不但能短暫忍受低海拔地區所出現的夏季高溫,也能至少存活3個月。我由此推論雪山草蜥對高溫的耐受能力應該不是限制其分布於高海拔地區的生理特徵。 在第二章,我研究台灣草蜥及蓬萊草蜥對低溫的耐受能力是否為造成其無法分布於高海拔地區的主要原因。我測量牠們的臨界低溫值 (critical thermal minimum)以及其在四種恆定低溫 (2 oC、5 oC、10 oC及 15oC) 處理下三個月的存活率。雪山草蜥則作為對照組。結果顯示: (一) 這三種草蜥的臨界低溫值與牠們海拔分布上界呈現正相關,(二) 台灣草蜥及蓬萊草蜥在5oC 處理下仍能有合理的存活率,而5oC相當於高海拔地區冬季時地底50公分深度的溫度。我由上述結果推論台灣草蜥及蓬萊草蜥對低溫的耐受能力應該不是影響牠們現有海拔分布範圍的生理特徵。 在第三章,我測量雪山草蜥的運動表現對溫度的敏感度 (thermal sensitivity) ,以研究其運動表現能力是否在低海拔的氣溫下會受到抑制,進而不利於生存在低海拔地區。我測量其衝刺速度以評估其運動表現能力,實驗蜥蜴分別先以兩種溫度馴養兩週後,再測量其於九種體溫下的衝刺速度。台灣草蜥則作為對照組。結果顯示: (一) 雪山草蜥在低海拔地區的溫度範圍下仍能維持優良的衝刺速度,(二) 當這兩種蜥蜴的體溫落在低海拔地區的氣溫範圍內時,台灣草蜥的衝刺速度顯著大於雪山草蜥的衝刺速度,(三) 這兩種蜥蜴的衝刺速度對溫度的敏感度沒有顯著差異,所以生存在不同海拔的溫度環境下並未驅使牠們的溫度生理產生分化;以及 (四) 馴化溫度處理對這兩種蜥蜴衝刺速度的表現沒有顯著影響。基於上述結果,我認為雪山草蜥的衝刺速度也不是限制其分布在高海拔地區的主要因素。 在第四章,我將雪山草蜥自高海拔地區移至台北市立動物園,並圈養在戶外的圈養場內為期一年。在實驗期間,我供給其足夠飲水、食物及遮蔽物,並隔絕或移除其潛在的天敵。我每週測量及記錄其生存率、體重變化及健康情形。台灣草蜥則作為對照組。結果顯示: (一) 雪山草蜥在6個月內能維持合理的存活率,並且其與台灣草蜥的存活率沒有顯著差異,(二)雪山草蜥在第9個月及第12個月時的存活率分別僅剩下 41.9% 及19.3%,其值顯著低於台灣草蜥同時期的存活率 (80.6 %),(三) 雪山草蜥在夏季的生長狀況良好,體重有增加現象。然而,其在冬季時無法成功蛻皮,並且有些個體有腳趾潰爛及眼疾等現象。相較之下,台灣草蜥則在冬季未顯現蛻皮跡象,具有上述不健康狀況的個體數量顯著較少。基於上述這些結果,我認為低海拔地區應該對雪山草蜥的生存不利,並且其冬季的環境因子極可能扮演重要角色。但由於這個實驗僅維持一年,仍需做更深入一歩的研究才能證實這項推測。 综言之,低溫耐受度及高溫耐受度應該不是限制三種草蜥海拔區隔的主要因素。對雪山草蜥而言,低海拔環境溫度對其運動表現並未產生抑制效應,所以溫度因子並未透過這幾項生理特徵影響牠們的海拔分布,未來若能檢測其他重要的生理特徵將更能釐清溫度因子對這三種草蜥海拔分布的影響程度。雪山草蜥在低海拔地區野外圈養場的存活狀況不佳,這可能與低海拔地區的氣候因素及微生物因素有關,這項推測仍需進一步研究證實。zh_TW
dc.description.abstractUnderstanding the factors that determine a species’ range is a central objective in ecology and evolutionary biology. It also provides important information in predicting species distributions in response to environmental changes and future conservation. This thesis examined the effect of environmental factor, mainly on abiotic factors, on three Takydromus lizards living at different altitudinal ranges in Taiwan. These three Takydromus lizards are the high mountainous T. hsuehshanensis (> 1800m in altitude), T. formosanus (recently revised as T. viridipunctatus,< 1500m in altitude) and lowland T. stejnegeri (< 500m). This study had two main objectives: one was to investigate the difference in thermal physiology and its role on altitudinal distributions of these three species, another was focusing on the mountainous T. hsuehshanensis to investigate whether it was able to live well under the lowland environment. To achieve the first objective I analyzed three thermal physiological traits of these three species: the heat thermal tolerance, the cold thermal tolerance, and the sprint speed. To achieve the second objective I conducted a transplant experiment on the mountainous T. hsuehshanensis. I moved it to the semi-natural outdoor enclosures in lowland areas and recorded its growth and survival rates during one year period. In chapter 1, I investigated whether heat tolerance was a crucial factor for the altitudinal distributions of T. hsuehshanensis. T. formosanus and T. stejnegeri were served as comparative groups. I measured and compared their critical thermal maximum (CTMax) and survival rates under 3 fluctuating daily temperature treatments over a 3 month period. Two of the 3 temperature treatments, the extremely high temperature (EH treatment) and the average temperature (H treatment), were set to approximate lowland summer temperatures. The third one was set to approximate the cool temperatures in mountain areas (C treatment). The results showed that (1) CTMax of T. hsuehshanensis was higher than the summer temperature in the lowland areas, but was not significantly lower than those of the other two lowland species, (2) T. hsuehshanensis survived the H and EH treatments for over a 3 month period and its survival rate was not significantly lower than that of the other two lowland species. Therefore, T. hsuehshanensis was not only able to tolerate high temperatures mimicking lowland areas for a short period of time, but also for a much longer period of time. I concluded that the heat tolerance of T. hsuehshanensis is not a crucial factor limiting its current altitudinal distribution. In chapter 2, I investigated whether cold tolerance was an important limiting factor for the current altitudinal distributions of two Takydromus lizards, T. formosanus and the lowland-dwelling T. stejnegeri in Taiwan. I measured their critical thermal minimum (CTMin) and 3-month survival rates in 4 cold treatments, and compared these with T. hsuehshanensis. The results indicated that (1) both the CTMin and prolonged cold tolerance were correlated with their upper limit of altitudinal distributions as predicted and (2) T. formosanus and T. stejnegeri had reasonable survival rates at temperatures that were lower than the underground temperature of high altitudinal areas. I concluded that although cold tolerance was correlated with altitudinal distribution, it is not a crucial factor limiting T. formosanus and T. stejnegeri in higher altitudes. In chapter 3, I investigated the impact of environmental temperature on altitudinal distributions of T. hsuehshanensis by examining its thermal sensitivity of locomotor performance. Its sprint speed was measured at nine body temperatures after two weeks acclimation at two different temperatures. The same measurement was performed on T. formosanus. The results indicated that (1) T. hsuehshanensis was capable of maintaining normal locomotor performance within a body temperature range approximating summer temperatures of lowland areas; (2) T. formosanus was able to run significantly faster than T. hsuehshanensis in body temperatures range of 20oC to 40 oC; (3) these two species did not differ in thermal sensitivity of locomotor performance; and (4) temperature acclimation did not affect the locomotor performance of these two species. I concluded that locomotor performance was not a factor limiting the distribution of T. hsuehshanensis to lowland areas. In chapter 4, I checked the survivorship and growth rate of T. hsuehshanensis in semi-natural enclosures in a lowland area during one year period. I provided them with plenty of water, food, and shelters, and removed/isolated the potential predators. The results indicated that (1) T. hsuehshanensis could maintain a reasonable survival rate at least within the first 6 months, (2) at the 9th and 12th month, the survivorship of T. hsuehshanensis declined to 41.9% and 19.3% respectively, which was significantly lower than those of the T. formosanus (80.6% at both the 9th and 12th month), and (3) in the summer T. hsuehshanensis was able to survive well and to increase their body weights; while in the winter it remained active but was not able to perform a normal shedding and was detected to have fester toes and eye disease. Compared to T. hsuehshanensis, T. formosanus did not shed their skin in the winter and had significantly less individuals having fester toes and eye diseases. According to these results, I concluded that the lowland area was not a suitable environment for T. hsuehshanensis to establish population in its recent state. I also inferred that the environment in winter had a negative effect on year-round successful survival of T. hsuehshanensis in lowland areas. However, since this experiment lasted for only one year, further investigations are needed to confirm this conclusion. In summery, I have demonstrated that thermal tolerances were not crucial physiological factors that limited the altitudinal distributions of these 3 species. The locomotion capacity of T. hsuehshanensis was not reduced in the temperatures approximating lowland temperatures. Further examination on other important traits will help to clarify the temperature effect on the altitudinal distributions of these three species. T. hsuehshanensis was not able to survive well in the outdoor enclosures in lowland areas, which may be due to the effects of climate or infective micro-organism in lowland area. Further investigations are needed to support my interpretation.en_US
dc.description.sponsorship生命科學系zh_TW
dc.identifierGN0891430012
dc.identifier.urihttp://etds.lib.ntnu.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=id=%22GN0891430012%22.&%22.id.&amp;
dc.identifier.urihttp://rportal.lib.ntnu.edu.tw:80/handle/20.500.12235/104420
dc.language英文
dc.subject溫度zh_TW
dc.subject海拔zh_TW
dc.subject蜥蜴zh_TW
dc.subject爬蟲類zh_TW
dc.subject地理分布zh_TW
dc.subject移地圈養zh_TW
dc.subjecttemperatureen_US
dc.subjectaltitudeen_US
dc.subjectlizarden_US
dc.subjectreptileen_US
dc.subjectgeographic distributionen_US
dc.subjecttransplant studyen_US
dc.title台灣三種草蜥之溫度生理及海拔分布之關係zh_TW
dc.titleThe thermal physiology and altitudinal distribution of three Takydromus lizards in Taiwanen_US

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