蚯蚓对不同阔叶落叶的摄食作用

采取室内试验,研究蚯蚓对红松阔叶混交林中几种不同阔叶的摄食量及影响因素、蚯蚓在不同阔叶中的生长状况和对有机碳和全氮的影响,探讨蚯蚓在东北红松阔叶混交林阔叶分解中的作用。蚯蚓喜食枫桦、紫椴和色木槭分解落叶,不喜食水曲柳分解落叶。试验表明,温度、凋落叶种类和凋落叶的分解时间等因素影响蚯蚓摄食量的大小。蚯蚓对3种喜食分解落叶摄食量平均值为:枫桦>色木槭>紫椴。不同温度条件下蚯蚓摄食量平均值为:20℃>25℃>15℃。凋落叶分解时间越长,蚯蚓越喜食,其摄食量也越大。分解落叶的C/N比新鲜凋落叶低。蚯蚓在3种凋落叶中的日增重倍数和日排粪量随着温度的升高而增加。不同温度下蚯蚓日增重倍数的平均值为25℃>20℃>15℃。蚯蚓在紫椴凋落叶中日增重倍数高于枫桦和色木槭分解落叶,在色木槭分解落叶的摄食过程中日排粪平均值高于紫椴和枫桦凋落叶。微生物对落叶中有机碳分解40d的作用小于蚯蚓对落叶摄食20d。蚯蚓摄食20d对增加凋落叶中的全氮含量的作用大于微生物单独分解40d。在凉水国家级自然保护区,蚯蚓对阔叶凋落叶的分解占年平均凋落叶量的10.3%左右。蚯蚓在红松阔叶混交林中阔叶分解中的作用不可忽视。     

真(鱼岁)(Phoxinus phoxinus(L.))的能量收支各组分与摄食量、体重及温度的关系

在不同的摄食水平(饥饿—最大量)及温度(5—15℃)下,对1—5g的真(鱼岁)的摄食量、排粪量、排泄量、代谢量,生长量及生化组成作了测定。真(鱼岁)的最大摄食量随体重及温度增加而增加。食物能量平均有6.5％损失于粪便中,5.1％损失于排泄物中。摄食代谢随摄食量增加而增加。在同一温度下,特定生长率与摄食量的关系是一减速增长曲线。当摄食不受限制时,生长率随温度增加而增加;当摄食受限制时,生长率随温度增加而下降。鱼体的干物质含量及能量含量随摄食量增加而增加。     

陆地生态系统中马陆的生态功能

马陆是陆地生态系统中物种多样性极高的大型土壤无脊椎动物类群。作为营腐生动物, 马陆在陆地生态系统中具有不可替代的重要功能。通过大量取食及随后的肠道过程, 马陆在很大程度上决定着陆地生态系统凋落物的破碎、转化和分解过程, 从而驱动碳和关键养分元素的循环周转。然而, 目前对马陆生态功能的研究还非常有限, 远远落后于其他土壤动物类群(如蚯蚓等)。本文初步总结了马陆的生态功能: (1)通过破碎、取食凋落物来加速凋落物的分解。马陆偏好取食半分解的凋落物, 其同化效率受到凋落物来源、温度和凋落物中微生物含量的影响。(2)主要通过取食和排泄等活动影响养分循环。但对于马陆如何影响土壤碳循环, 存在两种不同的观点: 一是马陆粪球的分解速率比凋落物更快, 加速了碳的循环; 二是马陆粪球更难分解, 有助于碳的固存和稳定。马陆破碎凋落物后, 凋落物释放氮素进入土壤。此外, 马陆的活动也影响土壤磷的循环, 提高土壤中有效磷的含量。(3)调控微生物特性, 与蚯蚓也有互作关系。通过以上三个方面的总结, 展望了未来马陆的主要研究方向, 以期引起更多思考和研究。     

森林凋落物与大型土壤动物相关关系的研究

以针阔混交林及落叶阔叶林为例,探讨了森林凋落物与大型土壤动物的相关关系。研究表明,森林凋落物中大型土壤动物的个体数依林型、凋落物厚度、凋落物量不同而异,凋落物的分解程度影响大型土壤动物的种类、数量分布,凋落物中矿质元素含量与大型土壤动物体内矿质元素含量相关较好,凋落物中微量元素含量与大型土壤动物体内微量元素含量明显不相关。本研究为揭示大型土壤动物在凋落物分解中的作用,进而为森林的经营和保护提供科学依据。     

内蒙古东部天然白桦林的凋落物性质和储量及其随温度和降水梯度的变化格局

作为碳素和养分循环的重要组分, 地表凋落物如何响应全球气候变化日益受到重视。中国北方半干旱地区森林草原过渡带斑块状分布的森林对气候变化引起的水热变化的响应较为敏感, 但是对这些森林地表处于不同分解阶段的凋落物的化学性质和储量的格局及其如何响应温度、降水变化的报道较少。该研究分析了内蒙古东部地区处于年平均气温和年降水量梯度上的12个天然白桦(Betula platyphylla)林不同凋落物层次(最上层的初步分解层L1, 中间的半分解层L2, 最下层的腐殖质层L3)的化学性质及现存量后发现: 1)随着分解的进行(即从L1到L3层), 氮、磷浓度显著增加, 可提取物浓度基本不变, 酸溶性组分(acid soluble fraction, AS)浓度下降, 酸不溶性组分(acid insoluble fraction, AIF)浓度增加。2)各元素现存量均在L3层最高, 表明凋落物分解缓慢, 养分积累。3)年平均气温和年降水量对凋落物有机组分(AS组分和AIF组分)的性质无显著影响, 但L3层元素储量随年平均气温升高而增加, 可能由于年平均气温较高的地点森林生产力更高, 从而导致叶凋落物量增加, 但由于受水分限制(尤其是在夏天), 这些地点的凋落物分解速率不变或更低, 使凋落物积累更为明显。上述结果表明: 腐殖质层是这些白桦林的一个重要的碳及养分库, 未来在降水没有明显变化的情况下, 这一区域的升温可能会增加白桦林地表凋落物储量。     

赤子爱胜蚓对森林凋落物的分解效率

蚯蚓是帽儿山林区的主要土壤动物类群。饲养实验表明,赤子爱胜蚓(Eiseniafoetida)对不同种类、不同腐解程度的木本植物叶片的摄食量不同,对未分解叶的食性偏好依次为:白桦(Betulaplatyphylla)>杨(Populusdavidiana)>红松(Pinuskoraiensis)>蒙古栎(Quercusmongolica),对半分解叶的食性偏好依次为:杨>红松>蒙古栎>白桦,对同种叶片半分解叶的消耗能力大于未分解叶。这表明叶片种类和叶子腐化程度是影响蚯蚓摄食偏好的两个主要因素,混交林比纯林更有利于蚯蚓对难腐化叶片种类的分解。研究还表明,赤子爱胜蚓生物量在盛夏、春末以增重为主,夏初、秋初以失重为主,对落叶的消耗能力随种群生物量增大而增大,摄食量随温度的升高而增大,说明影响蚯蚓分解能力的另两个重要因素是种群生物量和温度。比较研究表明,从不适宜条件到适宜条件,蚯蚓消耗能力的理论范围约为6.378~27mg/(d·g)。能流研究表明,不同生境下,蚯蚓的各种生态效率变辐较大,即,毛增长效率:2.34%~9.92%,组织增长效率:28.95%~90.86%,同化效率:8.10%~34.27%,粪便率:65.73%~91.90%。赤子爱胜蚓的毛增长效率与同化效率约为该林区另一类主要土壤动物马陆的两倍,是帽儿山森林生态系统的重要分解者。因此,通过林木种类优化配置、温湿度条件的改变,可提高蚯蚓种群生物量及其分解能力,加快寒区厚积凋落物层的分解,加速林分更新。     

花椒（Zanthoxylum bungeanum）凋落物分解过程中酚酸的释放及其浸提液对土壤化学性质的影响

应用分解网袋法研究了花椒凋落物分解过程中（0、10、30d和60d）酚酸的释放动态及凋落物浸提液对花椒林地土壤化学性质的影响。结果表明：花椒凋落物在分解过程中呈现出明显的毒性动态。凋落物分解的60d中,凋落物残留量在前30d内变化最大,30d后无显著变化;凋落物中酚酸含量随分解时间的延长,呈显著降低的趋势,且在分解10d时,酚酸释放量最大。4个分解动念的凋落物浸提液显著地改变了土壤好气性自生固氮菌、氨化细菌、好气性纤维素分解菌的数量和土壤pH值、酚酸含量、铵态氮、有效磷等化学性质。不同分解时间的凋落物浸提液均造成了土壤pH值的显著升高;分解10d的凋落物浸提液对土壤铵态氮的含量具有显著的降低作用,对土壤好气性自生固氮菌和氨化细菌的生长均具有显著的促进作用,而对好气性纤维素分解菌的生长具有抑制作用;分解60d的凋落物浸提液显著地降低了土壤酚酸含量,对土壤有效磷含量具有显著的升高作用,对好气性自生固氮菌的生长具有抑制作用,而对好气性纤维素分解菌的生长具有促进作用。     

两种陆栖等足类的种群及其分解落叶的作用

采用固定路线进行种群数量调查,并用落叶饲养,测定食性、食量,以探讨潮虫、鼠妇在广东小良人工阔叶混交林中分解落叶的作用。结果:(1)潮虫Philoscia sp.喜湿,主要分布于低湿、荫蔽处;鼠妇Armadillo sp.耐干旱,主要分布在较高爽处。(2)两种虫的种群数量高峰均在6月份。潮虫繁殖期延长到雨季之后,鼠妇则在雨季高峰前结束。(3)对未经沤化过的落叶多选食薄且质软的。鼠妇在25℃时摄食量最大,为117.1±12.4毫克/克体重·天;潮虫在20℃时食量最大,为251.2±7.3毫克/克体重·天。 通过种群年生物量变化及不同温度下的摄食量等因素来推算林中等足类的年分解落叶量:在荫蔽潮湿的林下,其分解量最大,占凋落物的自然消耗量的11.4％。     

我国中东部不同气候带成熟林凋落物生产和分解及其与环境因子的关系

在大尺度气候梯度上研究森林凋落物生产分解与气候因子的关系,对于了解森林生态系统碳循环有着重要的作用.在寒温带的黑龙江呼中、温带的吉林长白山、暖温带的北京东灵山、北亚热带的湖北神农架、中亚热带的四川都江堰和浙江古田山,选择典型地带性成熟林,设置72个样地.观测和研究各地点森林凋落物的产量、凋落动态和分解速率,分析三者与环境因子之间的关系,结果表明:不同气候带森林生态系统凋落物年产量为亚热带森林＞暖温带森林＞温带森林＞寒温带森林.随纬度的增加,凋落物产量逐渐减少,凋落物产量与森林类型极显著相关,与年均温显著相关,而与年均降水关系不显著.凋落物生产动态表现为亚热带地区3个类型森林生态系统为双峰型,暖温带、温带、寒温带3个类型森林生态系统为单峰型.凋落物分解速率k表现出了与凋落物产量相似的变化趋势,即随着纬度的增加,分解速率k值逐渐降低,分解速率与年均温极显著相关,与年均降水显著相关.     

凋落物层对东北羊草草原微环境的影响

采用模拟方法,建立不同量凋落物层,凋落物量范围为0～1000g.m-2,梯度为100g.m-2,探讨凋落物层对草原微环境影响。研究结果表明,土壤水分总的趋势随着凋落物量的增加,土壤含水量逐渐提高,当凋落物量达到一定时趋于平稳状态;地表温度和地下温度(5cm)变化趋势在各月份基本相似,均随凋落物层厚度增加而降低,至一定厚度达到稳定;土壤pH值和电导率与凋落物量均呈显著负相关;有凋落物层土壤中有机质、N、P、K的含量均高于无凋落物层的含量,其含量随凋落物量而逐渐升高。凋落物平均每增加100g.m-2,有机质提高17.9%,N提高7.6%,P提高26.4%,K提高3.8%。当凋落物量达600g.m-2时,有机质含量比无凋落物层提高了近1.8倍,N提高81.5%,P提高1.8倍,K提高24.6%。     

羊草草原枯枝落叶分解的研究——枯枝落叶分解与生态环境的关系

枯枝落叶的分解受生态环境的影响,枯枝落叶置于不同的生态环境下,其分解速率不同。例如,羊草(Leymus chinensis)在6种不同生境中的分解存在着明显差异。枯枝落叶位于地表和地下,其分解速率则不同,埋入地下的分解比位于地表的迅速。分解速率与土壤水分、地表温度和土壤pH呈指数正相关,与相对湿度呈线性正相关,它们对分解有积极的促进作用。通过生态因子对分解影响的综合分析表明,在羊草草原上,诸生态因子对枯枝落叶分解的重要性依次为:土壤水分、土壤pH、地表温度、相对湿度。     

Invertebrate prey and predatory behaviour of the omnivorous African tortoise Kinixys spekii

Invertebrates form an important part of the diet in the omnivorous African tortoises of the genus Kinixys. Millipede prey of Kinixys spekii in Zimbabwe had a mean volume of 0.9 ml, and made up 64.7% of invertebrate food by volume; beetles made up most of the remainder and had a mean volume of 1.4 ml. The mean mass of invertebrate prey was 0.19% of tortoise mass, a similar value of relative prey mass to many insectivorous lizards. Tortoises preferentially attacked moving millipedes at or just behind the head, but predatory behaviour was otherwise unspecialized, with tortoises killing millipedes by ingesting them in pieces. Handling times of millipede prey varied significantly with relative prey mass, defensive behaviour, and direction of ingestion. The profitability (mass intake/handling time) of millipedes was maximal at a relative prey mass of 0.2%; the basis on which prey are selected is discussed.     

Seasonal abundance and activity of pill millipedes (Arthrosphaera magna) in mixed plantation and semi-evergreen forest of southern India

Seasonal occurrence and activity of endemic pill millipedes (Arthrosphaera magna) were examined in organically managed mixed plantation and semi-evergreen forest reserve in southwest India between November 1996 and September 1998. Abundance and biomass of millipedes were highest in both habitats during monsoon season. Soil moisture, conductivity, organic carbon, phosphate, potassium, calcium and magnesium were higher in plantation than in forest. Millipede abundance and biomass were about 12 and 7 times higher in plantation than in forest, respectively (P < 0.001). Their biomass increased during post-monsoon, summer and monsoon in the plantation (P < 0.001), but not in forest (P > 0.05). Millipede abundance and biomass were positively correlated with rainfall (P = 0.01). Besides rainfall, millipedes in plantation were positively correlated with soil moisture as well as temperature (P = 0.001). Among the associated fauna with pill millipedes, earthworms rank first followed by soil bugs in both habitats. Since pill millipedes are sensitive to narrow ecological changes, the organic farming strategies followed in mixed plantation and commonly practiced in South India seem not deleterious for the endangered pill millipedes Arthrosphaera and reduce the risk of local extinctions.     

Role of Aerobic Microbial Populations in Cellulose Digestion by Desert Millipedes

I examined the role of aerobic microbial populations in cellulose digestion by two sympatric species of desert millipedes, Orthoporus ornatus and Comanchelus sp. High numbers of bacteria able to grow on media containing cellulose, carboxymethyl cellulose, or cellobiose as the substrate were found in the alimentary tracts of the millipedes. Enzyme assays indicated that most cellulose and hemicellulose degradation occurred in the midgut, whereas the hindgut was an important site for pectin degradation. Hemicellulase and β-glucosidase in both species and possibly C_x-cellulase and pectinase in O. ornatus were of possible microbial origin. Degradation of [¹⁴C]cellulose by millipedes whose gut floras were reduced by antibiotic treatment and starvation demonstrated a reduction in ¹⁴CO₂ release and ¹⁴C assimilation and an increase in ¹⁴C excretion over values for controls. It appears that the millipede-bacterium association is mutualistic and makes available to millipedes an otherwise mostly unutilizable substrate. Such an association may be an important pathway for decomposition in desert ecosystems.     

AGGREGATION BEHAVIOUR IN JUVENILE MILLIPEDES FROM THE UPPER CARBONIFEROUS OF MAZON CREEK, ILLINOIS

Abstract:  Two ironstone nodules are described from the Braidwood Biota of the Upper Carboniferous Mazon Creek Lagerstätte, Illinois, each preserving numerous juvenile millipedes referred to Euphoberia sp. The millipedes belong to different stadia, as evidenced by segment number, but are similar in size so probably nearly the same age. These juvenile euphoberiids differ from adults in having shorter pleurotergal spines, a reduced number of ocelli and a series of reduced, apodous trunk rings posteriorly. These nodules provide the first evidence of aggregation behaviour in Palaeozoic millipedes. Aggregation in juvenile euphoberiids is hypothesized to serve as a defence mechanism, compensating for the reduced length of their pleurotergal spines relative to adults, possibly through a collective chemical defence.     

Presence of circadian rhythms in the locomotor activity of a cave-dwelling millipede Glyphiulus cavernicolus sulu (Cambalidae, Spirostreptida)

The locomotor activity of the millipede Glyphiulus cavernicolus (Spirostreptida), which occupies the deeper recesses of a cave, was monitored in light-dark (LD) cycles (12h light and 12h darkness), constant darkness (DD), and constant light (LL) conditions. These millipedes live inside the cave and are apparently never exposed to any periodic factors of the environment such as light-dark, temperature, and humidity cycles. The activity of a considerable fraction of these millipedes was found to show circadian rhythm, which entrained to a 12:12 LD cycle with maximum activity during the dark phase of the LD cycle. Under constant darkness (DD), 56.5% of the millipedes (n = 23) showed circadian rhythms, with average free-running period of 25.7h ± 3.3h (mean ± SD, range 22.3h to 35.0h). The remaining 43.5% of the millipedes, however, did not show any clear-cut rhythm. Under DD conditions following an exposure to LD cycles, 66.7% (n = 9) showed faint circadian rhythm, with average free-running period of 24.0h ± 0.8h (mean ± SD, range 22.9h to 25.2h). Under constant light (LL) conditions, only 2 millipedes of 11 showed free-running rhythms, with average period length of 33.3h ± 1.3h. The results suggest that these cave-dwelling millipedes still possess the capacity to measure time and respond to light and dark situations. (Chronobiology International, 17(6), 757-765, 2000)     

Diversity and function of fungi associated with the fungivorous millipede,Brachycybe lecontii

Fungivorous millipedes (subterclass Colobognatha) likely represent some of the earliest known mycophagous terrestrial arthropods, yet their fungal associates remain elusive. Here we describe relationships between fungi and the fungivorous millipede, Brachycybe lecontii. Their fungal community is surprisingly diverse, including 176 genera, 39 orders, four phyla, and several undescribed species. Of particular interest are twelve genera conserved across wood substrates and millipede clades that comprise the core fungal community of B. lecontii. Wood decay fungi, long speculated to serve as the primary food source for Brachycybe species, were absent from this core assemblage and proved lethal to millipedes in pathogenicity assays while entomopathogenic Hypocreales were more common in the core but had little effect on millipede health. This study represents the first survey of fungal communities associated with any colobognath millipede, and these results offer a glimpse into the complexity of millipede fungal communities.     

Essential and alternative prey in a ponerine ant: variations according to the colony life cycle

We studied the prey specialization of Plectroctena minor, a ponerine ant known to capture mostly millipedes. We compared the prey spectrum of the hunting workers from large colonies with that of the founding queens. The hunting workers captured all kinds of tested prey, but hunted mostly millipedes. Founding queens, which avoided relatively large prey, including the millipedes tested, captured mostly isopods under experimental conditions. We also verified that the presence of millipedes in the diet of the larvae of large colonies was necessary for the production of winged females and strongly enhanced the production of workers, permitting us to assert that P. minor is a predatory species specialized in the capture of millipedes. In contrast, the presence of millipedes had no impact on the production of males. We thus assert that millipedes constitute the 'essential prey' of P. minor, while other arthropod taxa are therefore 'alternative prey'.     

Summer quiescent behaviour of the millipede Ommatoiulus moreleti (Julida: Julidae)

The millipede Ommatoiulus moreleti (Lucas), (Julidae) originates in the south-west Iberian Peninsula, and has successfully invaded parts of southern Australia with hot, dry summers. The species is inactive in the field during summer but is active in autumn, particularly following rains, and in spring. There is some activity in winter. In this paper, the temperature and humidity determinants of seasonal behaviour are analysed, in particular the conditions causing summer quiescence.
Experiments using a millipede treadmill apparatus at different temperatures at 95% RH showed an almost linear response of locomotor activity with temperature between 3 and 21°C, but when the temperature was increased to 28°C, the millipedes became quiescent. Activity could he restored by reducing the temperature.
When the millipedes were exposed to 45% RH there was comparatively little activity at any temperature. Field evidence indicates ii rapid breaking of quiescence with surface moisture
The success of O. moreleti in invading the surface-litter habitat in South Australia can he explained by its ability to avoid desiccation; its adaptations include its quiescent behaviour during summer and its ability to moult from a winter (reproductive) to B summer (non-reproductive) form.