Optional strategies for reduced metabolism in gray mouse lemurs

Among the order of primates, torpor has been described only for the small Malagasy cheirogaleids Microcebus and Cheirogaleus. The nocturnal, gray mouse lemur, Microcebus murinus (approx. 60 g), is capable of entering into and spontaneously arousing from apparently daily torpor during the dry season in response to reduced temperatures and low food and water sources. Mark–recapture studies indicated that this primate species might also hibernate for several weeks, although physiological evidence is lacking. In the present study, we investigated patterns of body temperature in two free-ranging M. murinus during the austral winter using temperature-sensitive data loggers implanted subdermally. One lemur hibernated and remained inactive for 4 weeks. During this time, body temperature followed the ambient temperature passively with a minimum body temperature of 11.5°C, interrupted by irregular arousals to normothermic levels. Under the same conditions, the second individual displayed only short bouts of torpor in the early morning hours but maintained stable normothermic body temperatures throughout its nocturnal activity. Reduction of body temperature was less pronounced in the mouse lemur that utilized short bouts of torpor with a minimum value of 27°C. Despite the small sample size, our findings provide the first physiological confirmation that free-ranging individuals of M. murinus from the humid evergreen littoral rain forest have the option to utilize short torpor bouts or hibernation under the same conditions as two alternative energy-conserving physiological solutions to environmental constraints.     

Torpor use during gestation and lactation in a primate

Torpor is an energy-saving mechanism that allows endotherms to overcome energetic challenges. Torpor should be avoided during reproduction because of potential incompatibility with offspring growth. To test if torpor can be used during gestation and lactation to compensate for food shortage, we exposed reproductive female grey mouse lemurs (Microcebus murinus), a heterothermic primate, to different levels of food availability. Torpor use was characterised by daily skin temperature profiles, and its energetic outcome was assessed from changes in body mass. Food shortage triggered torpor during the end of the gestation period (n = 1), ranging from shallow in response to 40% food restriction to deep daily torpor in response to 80% restriction. During the early period of lactation, females fed ad libitum (n = 2) or exposed to a 40% restriction (n = 4) remained normothermic; but 80% food restricted females (n = 5) gave priority to energy saving, increasing the frequency and depth of torpor bouts. The use of torpor was insufficient to compensate for 80% energetic shortage during lactation resulting in loss of mass from the mother and delayed growth in the pups. This study provides the first evidence that a heterothermic primate can use torpor to compensate for food shortages even during reproduction. This physiological flexibility likely evolved as a response to climate-driven fluctuations in food availability in Madagascar.     

Fat and fed: frequent use of summer torpor in a subtropical bat

A widely held view is that torpor is avoided by mammals whenever possible because of potential costs associated with reduced body temperatures and slowed metabolic processes. We examined this hypothesis by quantifying use of torpor in relation to body condition of free-ranging northern long-eared bats (Nyctophilus bifax, approximately 10 g), a species known to hibernate, from a subtropical region during the austral summer when insects were abundant. Temperature-telemetry revealed that bats used torpor on 85% of observation days and on 38% of all nights. Torpor bouts ranged from 0.7 to 21.2 h, but the relationship between duration of torpor bouts and ambient temperature was not significant. However, skin temperature of torpid bats was positively correlated with ambient temperature. Against predictions, individuals with a high body condition index (i.e., good fat/energy reserves) expressed longer and deeper torpor bouts and also employed torpor more often during the activity phase at night than those with low body condition index. We provide the first evidence that use of torpor in a free-ranging subtropical mammal is positively related with high body condition index. This suggests that employment of torpor is maximised and foraging minimised not because of food shortages or low energy stores but likely to avoid predation when bats are not required to feed.     

Regional,seasonal and interspecific variation in <Superscript>15</Superscript>N and <Superscript>13</Superscript>C in sympatric mouse lemurs

Madagascar provides some of the rare examples where two or more primate species of the same genus and with seemingly identical niche requirements occur in sympatry. If congeneric primate species co-occur in other parts of the world, they differ in size in a way that is consistent with Hutchinson’s rule for coexisting species, or they occupy different ecological niches. In some areas of Madagascar, mouse lemurs do not follow these “rules” and thus seem to violate one of the principles of community ecology. In order to understand the mechanisms that allow coexistence of sympatric congeneric species without obvious niche differentiation, we studied food composition of two identical sized omnivorous mouse lemur species, Microcebus griseorufus and M. murinus with the help of stable isotope analyses (δ ¹⁵N and δ ¹³C). The two species are closely related sister species. During the rich season, when food seems abundant, the two species do not differ in their nitrogen isotope composition, indicating that the two species occupy the same trophic level. But they differ in their δ ¹³C values, indicating that M. griseorufus feeds more on C₄ and CAM (Crassulacean-acid-metabolism) plants than M. murinus. During the lean season, M. murinus has lower δ ¹⁵N values, indicating that the two species feed at different trophic levels during times of food shortage. Hybrids between the two species showed intermediate food composition. The results reflect subtle differences in foraging or metabolic adaptations that are difficult to quantify by traditional observations but that represent possibilities to allow coexistence of species.     

The key to winter survival: daily torpor in a small arid-zone marsupial

Mammalian hibernation, which lasts on average for about 6 months, can reduce energy expenditure by >90% in comparison to active individuals. In contrast, the widely held view is that daily torpor reduces energy expenditure usually by about 30%, is employed for a few hours every few days, and often occurs only under acute energetic stress. This interpretation is largely based on laboratory studies, whereas knowledge on daily torpor in the field is scant. We used temperature telemetry to quantify thermal biology and activity patterns of a small arid-zone marsupial, the stripe-faced dunnart Sminthopsis macroura (16.9 g), in the wild and to test the hypothesis that daily torpor is a crucial survival strategy of this species in winter. All individuals entered torpor daily with the exception of a single male that remained normothermic for a single day (torpor on 212 of 213 observation days, 99.5%). Torpor was employed at air temperatures (T _a) ranging from approximately −1°C to 36°C. Dunnarts usually entered torpor during the night and aroused at midday with the daily increase of T _a. Torpor was on average about twice as long (mean 11.0 ± 4.7 h, n = 8) than in captivity. Animals employed sun basking during rewarming, reduced foraging time significantly, and occasionally omitted activity for several days in sequence. Consequently, we estimate that daily torpor in this species can reduce daily energy expenditure by up to 90%. Our study shows that for wild stripe-faced dunnarts daily torpor is an essential mechanism for overcoming energetic challenges during winter and that torpor data obtained in the laboratory can substantially underestimate the ecological significance of daily torpor in the wild.     

To use or not to use torpor? Activity and body temperature as predictors

When food is limited and/or environmental conditions are unfavourable, many mammals reduce activity and use torpor to save energy. Nevertheless, reliable predictors for torpor occurrence, especially in the wild, are currently not available. Interrelations between torpor use and other energy conserving strategies are also poorly understood. We tested the hypothesis that reductions in normothermic body temperature (T _b) and the period of activity before torpor events could be used as predictors for torpor occurrence in sugar gliders, Petaurus breviceps (body mass, ∼125 g), known to display daily torpor in the wild. Occurrence of torpor was preceded by significant (∼10–25%) reductions of the duration of the activity phase. Moreover, the normothermic resting T _b fell by an average of 1.2°C over 3 days before a torpor event, relative to individuals that did not display torpor. Our new findings suggest that before entering torpor, sugar gliders, which appear to use torpor as an emergency measure rather than a routine energy saving strategy, systematically reduce activity times and normothermic resting T _bs to lower energy expenditure and perhaps to avoid employing torpor. Thus, reduced activity and normothermic T _b may provide a predictive tool for the occurrence of daily torpor in the wild.     

Torpor and basking in a small arid zone marsupial

The high energetic cost associated with endothermic rewarming from torpor is widely seen as a major disadvantage of torpor. We tested the hypothesis that small arid zone marsupials, which have limited access to energy in the form of food but ample access to solar radiation, employ basking to facilitate arousal from torpor and reduce the costs of rewarming. We investigated torpor patterns and basking behaviour in free-ranging fat-tailed dunnarts Sminthopsis crassicaudata (10 g) in autumn and winter using small, internal temperature-sensitive transmitters. Torpid animals emerged from their resting sites in cracking soil at ∼1000 h with body temperatures as low as 14.6°C and positioned themselves in the sun throughout the rewarming process. On average, torpor duration in autumn was shorter, and basking was less pronounced in autumn than in winter. These are the first observations of basking during rewarming in S. crassicaudata and only the second direct evidence of basking in a torpid mammal for the reduction of energetic costs during arousal from torpor and normothermia. Our findings suggest that although overlooked in the past, basking may be widely distributed amongst heterothermic mammals. Therefore, the energetic benefits from torpor use in wild animals may currently be underestimated.     

Hibernation in Malagasy mouse lemurs as a strategy to counter environmental challenge

The spiny forest of southwestern Madagascar is the driest and most unpredictable region of the island. It is characterized by a pronounced seasonality with high fluctuations in ambient temperature, low availability of food, and a lack of water during the cool dry season and, additionally, by changes in environmental conditions between years. One of the few mammalian species that manages to inhabit this challenging habitat is the reddish-gray mouse lemur (Microcebus griseorufus). The aim of our study was to determine whether this small primate uses continuous hibernation as an energy saving strategy, and if so, to characterize its physiological properties. We measured skin temperature of 16 free-ranging individuals continuously over 3 months during the cool dry season using collar temperature data loggers. Prolonged hibernation was found in three mouse lemurs and was not sex dependent (one male, two females). Skin temperature of hibernating individuals tracked ambient temperature passively with a minimum skin temperature of 6.5°C and fluctuated strongly each day (up to 20°C), depending on the insulation capacity of the hibernacula. Individuals remained in continuous hibernation even at an ambient temperature of 37°C. The animals hibernated continuously during the dry season, and hibernation bouts were only interrupted by short spontaneous arousals. The study emphasizes that hibernation is an important measure to counter environmental challenge for more tropical species than previously thought, including primates. It furthermore provides evidence that tropical hibernation is functionally similar among tropical species.     

不同植被下森林地表系统水相硫的分布与迁移

为了阐明酸雨对森林生态系统水相硫动态分布的影响,在1997~1999年以庐山植物园的针叶林和阔叶林为研究对象,对降雨、透冠水、干流水、渗漏水、径流水及硫通量进行了监测分析。结果表明,降水中SO2-4含量最高值出现在冬季,最低值在夏季;针叶林和阔叶林的透冠水、干流水和渗漏水中的SO2-4含量均高于降水,且透冠水和干流水均表现为春夏季较低、秋冬季较高,径流水变化与之相反;渗漏水针叶林冬季最高,阔叶林春季最高,其他三个季节差异不大;森林生态系统水相硫年际变化呈递增趋势,即1997年1998年1999年,1999年SO2-4浓度与1998和1997年之间差异达显著或极显著水平,而1997年和1998年差异不显著;针叶林的透冠水、干流水、渗漏水中的SO2-4含量均比阔叶林高,而径流水则比阔叶林低,其pH值变化与之相反。针叶林和阔叶林都能够较好的吸收大气沉降中的S,其固定量均高于降水中S的通量,故庐山森林生态系统目前仍是大气S沉降的汇,对酸沉降仍有缓冲作用,但针叶林由于高输入低输出,因此对S的固定能力更强。     

模拟酸雨对毛竹入侵阔叶林缓冲区土壤细菌群落多样性的影响

为了分析酸雨对毛竹入侵阔叶林缓冲区土壤细菌群落多样性的影响,以浙江省天目山国家级自然保护区毛竹扩张形成的竹阔混交林为研究对象,选取T₁（pH=4.0）、T₂（pH=2.5）两个模拟酸雨梯度,并以pH=5.5为对照（CK）,应用Illumina MiSeq高通量测试技术分析不同强度酸雨胁迫下土壤细菌群落组成和多样性变化及其关键影响因素.结果表明:①随着酸雨强度增加,竹阔混交林土壤w（TN）（TN为总氮）、w（OC）（OC为有机碳）、C/N和w（AN）（AN为碱解氮）显著升高,而pH、w（DOC）（DOC为可溶性有机碳）、w（MBC）（MBC微生物量碳）和w（MBN）（MBN为微生物量氮）显著下降（P < 0.05）.②与CK相比,模拟酸雨处理（T₁、T₂）显著降低了细菌群落的OTUs数量、Chao1指数和Ace指数（P < 0.05）.③竹阔混交林土壤细菌包括34门96纲247目401科698属,其中变形菌门、酸杆菌门、绿弯菌门、放线菌门为3种处理下共有的优势菌门（相对丰度>1%）.变形菌门和放线菌门相对丰度在CK处理下最高,酸杆菌门和绿弯菌门相对丰度在T₂处理下最高.与CK相比,Arthrobacter属和Elsterales属相对丰度变化显著,可作为酸雨胁迫下土壤细菌群落结构变化的指示种.主坐标（PCoA）分析和相似性检验结果显示,模拟酸雨改变了土壤细菌群落结构.④冗余分析（RDA）和相关性分析表明,不同酸雨处理的竹阔混交林土壤细菌多样性与土壤pH、w（TN）密切相关（P < 0.05）.研究显示,不同模拟酸雨处理下土壤细菌群落结构和多样性有明显差异,主要可能受到土壤pH、w（TN）的影响.      

Torpor in free-ranging antechinus: does it increase fitness?

Antechinus are small, insectivorous, heterothermic marsupial mammals that use torpor from late summer to early winter and reproduce once a year in late winter/early spring. Males die after mating, most females produce only a single litter, but some survive a second winter and produce another litter. As it is not known how these females manage to survive the second winter after the energetically demanding reproductive period and then reproduce a second time, we aimed to provide the first data on thermal biology of free-ranging antechinus by using temperature telemetry. Male Antechinus stuartii and Antechinus flavipes rarely entered torpor in autumn/early winter in the wild, expressing only shallow bouts of <2 h. Female A. stuartii used torpor extensively, employing bouts up to 16.7 h with body temperatures as low as 17.8 °C. Interestingly, although first and second year females used similar torpor patterns, torpor occurrence was almost twofold in second year (93 % of days) than first year females (49 %), and the proportion of the overall monitoring period animals spent torpid was 3.2-fold longer in the former with a corresponding shorter activity period. Our study suggests that intensive use of torpor is crucial for second year females for autumn and winter survival and production of a second litter. We provide the first evidence of an age-related pattern in daily torpor expression in free-ranging mammals and show that torpor use is a complex process that is affected not only by the current energy availability and thermal conditions but also by the reproductive history and age of individuals.     

Vertebrate diet decreases winter torpor use in a desert marsupial

One of the energetic benefits of daily torpor over prolonged hibernation is that it enables animals to regularly forage and, therefore, replenish food reserves between bouts of torpor. However, little is known about the diet of predators undergoing torpor or whether differences in prey composition among individuals influence torpor characteristics. Here, we test the hypothesis that prey composition affects winter torpor use and patterns of a population of carnivorous marsupial, the brush-tailed mulgara (Dasycercus blythi), in the Great Sandy Desert, Australia. Mulgaras in the study population captured a wide range of prey including vertebrates (mammals, reptiles, birds), seven insect orders, spiders and centipedes. The proportion of vertebrates in the diet was negatively correlated with both frequency of torpor use and maximum bout duration. This variation in torpor use with diet can be explained by the higher energetic content of vertebrates as well as their larger size. Even assuming uniform intake of prey biomass among individuals, those that subsisted on an invertebrate-dominated diet during winter apparently suffered energetic shortages as a result of the scarcity of invertebrate taxa with high energy content (such as insect larvae). Our study is the first to demonstrate a link between diet composition and daily torpor use in a free-ranging mammal.     

Communally breeding bats use physiological and behavioural adjustments to optimise daily energy expenditure

Small endotherms must change roosting and thermoregulatory behaviour in response to changes in ambient conditions if they are to achieve positive energy balance. In social species, for example many bats, energy expenditure is influenced by environmental conditions, such as ambient temperature, and also by social thermoregulation. Direct measurements of daily fluctuations in metabolic rates in response to ambient and behavioural variables in the field have not been technologically feasible until recently. During different reproductive periods, we investigated the relationships between ambient temperature, group size and energy expenditure in wild maternity colonies of Bechstein’s bats (Myotis bechsteinii). Bats used behavioural and physiological adjustments to regulate energy expenditure. Whether bats maintained normothermia or used torpor, the number of bats in the roosts as well changed with reproductive status and ambient temperature. During pregnancy and lactation, bats remained mostly normothermic and daily group sizes were relatively large, presumably to participate in the energetic benefits of social thermoregulation. In contrast, smaller groups were formed on days when bats used torpor, which occurred mostly during the post-lactation period. Thus, we were able to demonstrate on wild animals under natural conditions the significance of behavioural and physiological flexibility for optimal thermoregulatory behaviour in small endotherms.     

Roost type influences torpor use by Australian owlet-nightjars

Australian owlet-nightjars (Aegotheles cristatus; ～50?g) are one of only a few avian species that roost in cavities year-round and regularly enter torpor. Cavity roosts act as thermal buffers, and roost type likely affects energy expenditure of small birds. We used radiotelemetry to locate diurnal winter roost sites of owlet-nightjars in central Australia and to measure body (T (b)) and skin (T (skin)) temperature. We also recorded ambient temperature inside (T (IN)) and outside roosts. Individual owlet-nightjars used one to seven different roosts (tracking time 3-10?weeks), selecting either rock crevices (four birds) or tree hollows (four birds), or switching between the two roost types (seven birds). Rock crevices (T (IN) +9°C to +33°C) were warmer and thermally more stable than tree hollows (T (IN) -4.0°C to +37°C). Torpor, often expressed by a reduction of T (skin)/T (b) by >10°C for 3-4?h at dawn, was influenced by roost selection; torpor use in tree hollows was almost twice that in rock crevices. Despite the potential energy savings accrued from roosting in well-insulated cavities, owlet-nightjars roosted in tree hollows more often (65% bird days, n?=?398) than in rock crevices (35% bird days, n?=?211). Lower costs of arousal from torpor via passive rewarming and basking and decreased risk of predation are two possible explanations for the preference to roost in tree hollows. We provide the first evidence for the influence of cavity roost selection on torpor use in a free-ranging bird and show that roost selection and thermal biology are strongly interrelated in determining energy expenditure.     

Torpor at high ambient temperature in a neotropical didelphid,the grey short-tailed opossum (Monodelphis domestica)

The grey short-tailed opossum, Monodelphis domestica, has been an established research animal for more than five decades, but relatively, little is known about its thermophysiology. Here we studied core body temperature (T _b) and metabolic rate (MR) of female adult M. domestica housed in the laboratory at an ambient temperature (T _a) of 26 °C. In expanding previous reports, the average recorded core T _b of M. domestica was 34.3 °C. The T _b of an individual M. domestica can drop below 30 °C (minimal T _b: 28.6 °C) accompanied by a reduction in MR of up to 52 % even while having ad libitum access to food. These findings demonstrate for the first time the presence of spontaneous torpor in M. domestica. Metabolic suppression at relatively high T _a and T _b furthermore broadens our perspective on the use of torpor as a metabolic strategy not just restricted to cold climates.     

Torpor and activity in a free-ranging tropical bat: implications for the distribution and conservation of mammals?

Bats are most diverse in the tropics, but there are no quantitative data on torpor use for energy conservation by any tropical bat in the wild. We examined the thermal biology, activity patterns and torpor use of two tree-roosting long-eared bats (Nyctophilus geoffroyi, 7.8?g) in tropical northern Australia in winter using temperature telemetry. Bats commenced activity about 20?min after sunset, ended activity about 2.5?h before sunrise and entered torpor everyday in the early morning even when minimum ambient temperatures (T _a) were as high as 23°C. On average, bats remained torpid for almost 5?h, mean minimum skin temperature (T _skin) measured was 22.8?±?0.1°C and daily T _skin minima were correlated with T _a. Our study shows that even in the tropics, torpor is frequently employed by bats, suggesting that worldwide most bat species are heterothermic and use torpor for energy conservation. We propose that the ability of employing torpor and the resulting highly plastic energy requirements may partially explain why these small insectivorous bats can inhabit almost the entire Australian continent despite vastly different climatic and likely trophic conditions. Reduced energy requirements also may permit survival in degraded or modified habitats, reduce the need for foraging and reduce exposure to predators. Thus, the ability to employ torpor may be one important reason for why most Australian bats and other heterothermic mammals have not gone extinct whereas many obligatory homeothermic mammals that cannot employ torpor and have high energy and foraging requirements have suffered high rates of extinctions.     

Metal pollution in relation to mass outbreaks of Dendrolimus punctatus Walker on Pinus massoniana Lamb.in China

Insects with their ecological superpower have enormous capacity to transform small pollution damage in forests to full scale calamities. Acid rain resulting from extensive coal burning is the chief pollutant in China. Acid rain activates from soil deposits toxic metals, which are transferred to trees and further to insects eating them. We studied the levels of the toxic Cd, its antagonists Zn and Cu, and acid rain indicators Fe and Mn in the forest pest moth Dendrolimus punctatus Walker (Lepidoptera:Lasiocampidae) in variously polluted Pinus massoniana Lamb forests in China. The highest density of D. punctatus, as well as the highest Cd levels developed in the moderately polluted forests. Possibly Cd had there broken down the pest resistance of the pines. The paradoxical coexistence of high Cd level and elevated population density of the pest seems to result from the high accumulation of Cd in its ichneumonid parasitoid. In the most heavily polluted forests the Cd level in needles was low, possibly because the strong acid rain had washed away most of the Cd deposit in the soil. It existed there no D.punctatus population. Absence of pest insects from the most heavily polluted areas is a common phenomenon.     

模拟酸雨对毛竹阔叶林过渡带土壤真菌结构及其多样性的影响

为探究酸雨对毛竹扩张形成的竹阔混交林土壤真菌群落的影响程度,于2017～2018年在浙江省杭州临安天目山国家级自然保护区开展酸雨模拟实验,选取T1(pH=4.0)和T2(pH=2.5)两个模拟酸雨梯度,并以CK(pH=5.5)对照,利用Illumina MiSeq高通量测序技术,分析不同强度酸雨胁迫下,土壤真菌群落多样性变化及影响因素.结果表明与对照相比,T1处理显著提高了真菌群落的OTU数量、Chao1指数和Ace指数(P0.05).竹阔混交林土壤主要由13个门类群的菌群组成,优势菌群包括子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、被孢霉门(Mortierellomycota)和毛霉门(Mucoromycota).主坐标(PCoA)分析和相似性检验结果表明模拟酸雨改变了土壤真菌结构.Bifiguratu属、Geminibasidium属、Purpureocillium属和Oidiodendron属相对丰度变化显著,可作为酸雨胁迫下土壤真菌群落结构变化的指示种.冗余分析(RDA)和相关性分析表明,土壤pH和全氮对土壤真菌群落结构影响显著(P0.05).综上所述,酸雨提高了真菌群落多样性指数,改变土壤真菌群落结构.该研究结果有助于了解森林生态系统中的真菌群落,以及土壤真菌作为影响因子在预测环境变异中的作用.     

两种沉水植物对风浪及持续高水位胁迫的适应性研究

以两种沉水植物马来眼子菜(Potamogeton malainus)和狐尾藻(Myriophyllum spicatum)为研究对象,通过原位模拟试验,比较在相同水位变化幅度下不同高水位持续胁迫水平(分别以T0、T1、T2、T3表示恒静止、持续4 d、持续8 d和持续12 d)对沉水植物的生物量、植株伸长、具体形态指标和光合荧光特性的影响,并同步分析滆湖大洪港内两处风浪差异区(湖岸区M1和湖心区M2)两种沉水植物相应的适应性和形态变化的特征.结果表明,马来眼子菜和狐尾藻都表现出了较好的环境适应性,T0时任意两处的两种植物生物量和株高均最大;在风浪扰动较小区域(M2),持续高水位减弱了两种植物的伸长和生长(p0.01),并显著限制其在地上生物量的投资和茎干横向的分支(p0.05).在风浪扰动较大区域(M1),持续高水位对两种沉水植物产生了相同的形态变化,并显著降低各梯度下其Fv/Fm和快速光响应曲线(p0.05),但M1处两种沉水植物的光合能力均显著大于M2处.狐尾藻对风浪扰动和长时间水位胁迫能表现出更强抗弱光性和光合作用能力.因此,持续高水位胁迫下(小于8 d)两种沉水植物对一定程度水动力仍有较好的形态和生长适应性,对特定水文波动特征进行合理应对以保持沉水植物活力和维持湖泊生态系统具有指导作用.     

喀斯特常绿落叶阔叶混交林旱季CO2通量特征及其影响因子

对广西木论国家级自然保护区喀斯特常绿落叶阔叶混交林旱季生态系统CO₂净交换（NEE）的变化特征及其与环境因子的关系进行初步分析，计算研究期间碳汇大小，与其他相似气候条件下的不同生态系统进行对比，以期为准确估算该生态系统的年碳汇量提供基础。利用涡度相关法对该地区旱季（2018年10月1日~2019年3月31日）CO₂通量进行连续观测，同时开展降水量（P）、光合有效辐射（PAR）、空气温度（T_air）、土壤温度（T_soil）以及土壤含水量（SWC）等环境因子监测。观测期内该生态系统CO₂通量及浓度具有明显的"单谷"状日变化特征，白天表现为明显的碳汇，夜间则表现为明显的碳源，NEE在12：00最强，为-0.309±0.330 mg CO₂/（m²·s），18：30最弱，为0.074±0.061 mg CO₂/（m²·s）；观测期内NEE、生态系统呼吸（Re）、生态系统总生产力（GEP）分别为-121.4、209.2、330.6 g C/m²，该生态系统在2019年2月的碳吸收能力最强，Re、GEP在2018年10月达到最强；光合有效辐射是白天生态系统CO₂净交换（NEE_d）变化的主要控制因素（R²=0.40，p<0.01），空气温度与夜间生态系统CO₂净交换（NEE_n）存在指数关系（R²=0.1267，p<0.01）；观测期内的降雨抑制了该生态系统的碳汇能力，即降水对NEE产生了抑制作用。旱季该生态系统整体表现出明显的碳汇，碳汇值为1.214 t C/ha，明显低于相似气候条件下的其他生态系统。