Pub Date : 2006-04-01DOI: 10.1127/0003-9136/2006/0165-0557
F. Gherardi, B. Renai, P. Galeotti, D. Rubolini
Under the rationale that behavioral studies may contribute to the conservation of threatened species, we analyzed mating behavior of the crayfish Austropotamobius italicus in the laboratory. Our objectives were to investigate whether nonrandom mating by size occurs in this species and to explore the role exerted by mate choice and male-male competition in inducing mating. We observed 17 "quartets" (one female and three differently sized males), divided into three groups based on the female size. To understand the influence of male-male competition on mating, we compared six quartets with six "duets" (one female and one male). Our results clearly show that mating in A. italicus is nonrandom caused by the clear mating advantage of larger males. In fact, as compared to smaller size categories, large males paired more often and for a longer time, and interrupted the final phase of mating less frequently. Male size-advantage mostly derives from an active female choice for large partners, combined with dominance of big males in intrasexual competition. However, a restricted mating period and the low number of receptive females may make males relatively indiscriminate in their overt behavior towards females. Female selection of big males and male-male competition over mates, also in the form of sperm competition, should result in a skewed reproductive success among males. As a consequence, populations with few big males would be characterized by a low heterozigosity and therefore by little genetic variation upon which selection acts. Our results should warn managers to pay more attention to the size structure of crayfish populations that are used for reintroductions.
{"title":"Nonrandom mating, mate choice, and male-male competition in the crayfish Austropotamobius italicus, a threatened species","authors":"F. Gherardi, B. Renai, P. Galeotti, D. Rubolini","doi":"10.1127/0003-9136/2006/0165-0557","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0557","url":null,"abstract":"Under the rationale that behavioral studies may contribute to the conservation of threatened species, we analyzed mating behavior of the crayfish Austropotamobius italicus in the laboratory. Our objectives were to investigate whether nonrandom mating by size occurs in this species and to explore the role exerted by mate choice and male-male competition in inducing mating. We observed 17 \"quartets\" (one female and three differently sized males), divided into three groups based on the female size. To understand the influence of male-male competition on mating, we compared six quartets with six \"duets\" (one female and one male). Our results clearly show that mating in A. italicus is nonrandom caused by the clear mating advantage of larger males. In fact, as compared to smaller size categories, large males paired more often and for a longer time, and interrupted the final phase of mating less frequently. Male size-advantage mostly derives from an active female choice for large partners, combined with dominance of big males in intrasexual competition. However, a restricted mating period and the low number of receptive females may make males relatively indiscriminate in their overt behavior towards females. Female selection of big males and male-male competition over mates, also in the form of sperm competition, should result in a skewed reproductive success among males. As a consequence, populations with few big males would be characterized by a low heterozigosity and therefore by little genetic variation upon which selection acts. Our results should warn managers to pay more attention to the size structure of crayfish populations that are used for reintroductions.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87470252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-04-01DOI: 10.1127/0003-9136/2006/0165-0537
A. Magnusson, D. Williams
The importance of top-down and bottom-up mechanisms in lentic systems has largely been explored in stable systems; however, their influence is likely to change along a habitat duration gradient. Using a case study of four intermittent ponds, we test the generality of these paradigms in systems nearing the extreme short end of this gradient. Intermittent ponds fill up with water on a seasonally predictable basis, and are considered more regulated by physicochemical constraints than by biological factors. We found that natural spatial (i.e., pond-to-pond) and temporal variations (i.e., seasonal and annual) were more important than food-web manipulations (i. e., exclusion of aerial colonization, addition of top-predators [beetle larvae and odonate nymphs], and addition versus removal of allochthonous resources [leaf litter] in field enclosures) in shaping the physicochemical environment. Spatial variation included mainly depth-related variables (e. g., conductivity and pH), whereas annual variation included variables associated with hydroperiod length and productivity (e. g., weeks after flooding, pH, nutrients, and chlorophyll-a). Seasonal variation was pronounced but lower in ponds with longer hydroperiod and in mid-season. Enhanced invertebrate predation pressure increased levels of chlorophyll-a. Exclusion of aerial colonizers increased levels of chlorophyll-a and phosphorus, and affected levels of dissolved oxygen (increasing in one pond and decreasing in another). Addition of leaf litter resulted in lower concentrations of dissolved oxygen, higher phosphorus, and lower pH. Leaf litter removal led to increased levels of dissolved oxygen, changed chlorophyll-a (increasing in one pond and decreasing in another), and higher pH (in one pond). We conclude that although pond characteristics, seasonal development, and annual differences were of greater importance than biological factors for shaping the physicochemical characteristics of these intermittent ponds, bottom-up and top-down effects were also influential.
{"title":"The roles of natural temporal and spatial variation versus biotic influences in shaping the physicochemical environment of intermittent ponds : a case study","authors":"A. Magnusson, D. Williams","doi":"10.1127/0003-9136/2006/0165-0537","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0537","url":null,"abstract":"The importance of top-down and bottom-up mechanisms in lentic systems has largely been explored in stable systems; however, their influence is likely to change along a habitat duration gradient. Using a case study of four intermittent ponds, we test the generality of these paradigms in systems nearing the extreme short end of this gradient. Intermittent ponds fill up with water on a seasonally predictable basis, and are considered more regulated by physicochemical constraints than by biological factors. We found that natural spatial (i.e., pond-to-pond) and temporal variations (i.e., seasonal and annual) were more important than food-web manipulations (i. e., exclusion of aerial colonization, addition of top-predators [beetle larvae and odonate nymphs], and addition versus removal of allochthonous resources [leaf litter] in field enclosures) in shaping the physicochemical environment. Spatial variation included mainly depth-related variables (e. g., conductivity and pH), whereas annual variation included variables associated with hydroperiod length and productivity (e. g., weeks after flooding, pH, nutrients, and chlorophyll-a). Seasonal variation was pronounced but lower in ponds with longer hydroperiod and in mid-season. Enhanced invertebrate predation pressure increased levels of chlorophyll-a. Exclusion of aerial colonizers increased levels of chlorophyll-a and phosphorus, and affected levels of dissolved oxygen (increasing in one pond and decreasing in another). Addition of leaf litter resulted in lower concentrations of dissolved oxygen, higher phosphorus, and lower pH. Leaf litter removal led to increased levels of dissolved oxygen, changed chlorophyll-a (increasing in one pond and decreasing in another), and higher pH (in one pond). We conclude that although pond characteristics, seasonal development, and annual differences were of greater importance than biological factors for shaping the physicochemical characteristics of these intermittent ponds, bottom-up and top-down effects were also influential.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78137592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-04-01DOI: 10.1127/0003-9136/2006/0165-0515
Bernd Spänhoff, C. Reuter, E. Meyer
Epixylic biofilm and invertebrate assemblages on pine branches (Pinus syl- vestris) experimentally submerged in October 2000 were investigated, after an initial colonization period of 3 months, by two-monthly sampling intervals for 13 months in a nutrient-rich sandy lowland stream subjected to flow disturbances caused by infre- quent impoundment openings. After 12 weeks of exposure an epixylic biofilm with 0.58 ± 0.25 µg/cm 2 chlorophyll-a (mean ± 1 SE) and 0.23 ± 0.04 µg/cm 2 ATP, as well as an abundant invertebrate community (14326 ± 2532 Ind/m 2 ; biomass: 974.6 ± 360.1 mg/m 2 ) became established on the branch surfaces. During the subsequent sam- pling dates invertebrate numbers decreased significantly during periods of high dis- charge and simultaneously chlorophyll-a values of epixylic biofilms increased, likely due to reduced feeding by invertebrate grazers. During periods with low discharge fluctuations and mainly low flow conditions, the epixylic biofilm, especially algal growth, was negatively correlated with invertebrate grazer and shredder numbers. After the initial growth period of 12 weeks, ATP values of the epixylic biofilm showed a strongly negative response to sand deposited on the wood surfaces. The present study displays the influence of seasonal discharge fluctuations and sand deposition on the wood surfaces on epixylic biofilms and invertebrate assembla- ges on experimentally submerged pine branches, but also indicate interactions between food sources (algae and fine particulate organic matter) and invertebrates (grazers and collector/gatherers).
{"title":"Epixylic biofilm and invertebrate colonization on submerged pine branches in a regulated lowland stream","authors":"Bernd Spänhoff, C. Reuter, E. Meyer","doi":"10.1127/0003-9136/2006/0165-0515","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0515","url":null,"abstract":"Epixylic biofilm and invertebrate assemblages on pine branches (Pinus syl- vestris) experimentally submerged in October 2000 were investigated, after an initial colonization period of 3 months, by two-monthly sampling intervals for 13 months in a nutrient-rich sandy lowland stream subjected to flow disturbances caused by infre- quent impoundment openings. After 12 weeks of exposure an epixylic biofilm with 0.58 ± 0.25 µg/cm 2 chlorophyll-a (mean ± 1 SE) and 0.23 ± 0.04 µg/cm 2 ATP, as well as an abundant invertebrate community (14326 ± 2532 Ind/m 2 ; biomass: 974.6 ± 360.1 mg/m 2 ) became established on the branch surfaces. During the subsequent sam- pling dates invertebrate numbers decreased significantly during periods of high dis- charge and simultaneously chlorophyll-a values of epixylic biofilms increased, likely due to reduced feeding by invertebrate grazers. During periods with low discharge fluctuations and mainly low flow conditions, the epixylic biofilm, especially algal growth, was negatively correlated with invertebrate grazer and shredder numbers. After the initial growth period of 12 weeks, ATP values of the epixylic biofilm showed a strongly negative response to sand deposited on the wood surfaces. The present study displays the influence of seasonal discharge fluctuations and sand deposition on the wood surfaces on epixylic biofilms and invertebrate assembla- ges on experimentally submerged pine branches, but also indicate interactions between food sources (algae and fine particulate organic matter) and invertebrates (grazers and collector/gatherers).","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76997629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0401
F. Gherardi, L. Lazzara
To understand the relationship between the density of an introduced crayfish species (P. clarkii) and the abundance and composition of pelagic and surface microalgae (hereafter referred to as phytoplankton and phytoneuston, respectively) we ran an in situ experiment in a Mediterranean wetland. In May 2004, we delimited six 10 x 7m areas along a channel in the "Padule di Fucecchio" (Italy). Each area was randomly chosen to host crayfish populations at either low (1 crayfish/m 2 ) or high densities (14 crayfish/m 2 ). Phytoplankton and phytoneuston samplings were conducted in August and in September 2004, corresponding to the periods in which the highest and the lowest numbers of free-moving crayfish were found, respectively, during the lentic phase of the water regime. Results showed that (1) phytoneuston biomass, composed of cyanobacteria and, to a lesser extent, of euglenoids, was strongly affected by the presence of dense populations of P. clarkii in August; (2) crayfish seemed to modify the composition of microalgal communities; (3) these effects were not accompanied by significant differences between experimental areas in water chemistry and temperature; (4) physico-chemical measures highly varied with sampling periods along with a change in phytoplankton and phytoneuston abundance; and (5) high crayfish densities did not to exert any measurable effect on phytoplankton abundance. The decrease of phytoneuston may be the result of top-down effects of crayfish removing invertebrate grazers or, most likely, of direct grazing of crayfish. Indeed, crayfish were often observed climbing on macrophytes and feeding on the floating film.
为了了解引进的克氏螯虾(P. clarkii)的密度与上层微藻和表层微藻(以下分别称为浮游植物和浮游生物)的丰度和组成之间的关系，我们在地中海湿地进行了原位实验。2004年5月，我们在“Padule di Fucecchio”(意大利)的一条水道上划定了6个10 x 7米的区域。每个区域随机选择小龙虾种群，以低密度(1只小龙虾/平方米)或高密度(14只小龙虾/平方米)进行饲养。在2004年8月和9月分别进行了浮游植物和浮游生物取样，对应于在水体状态的最后阶段发现自由移动的小龙虾数量最多和最少的时期。结果表明:(1)8月克拉氏假单胞菌密集种群的存在，对以蓝藻为主、以类绿藻为主的植藻生物量影响较大;(2)小龙虾似乎改变了微藻群落的组成;(3)各试验区的水化学和温度差异不显著;(4)物理化学指标随采样周期的变化以及浮游植物和浮游生物丰度的变化变化很大;(5)小龙虾的高密度对浮游植物的丰度没有显著影响。浮游生物数量的减少可能是小龙虾清除无脊椎食草动物的自上而下效应的结果，也可能是小龙虾直接放牧的结果。事实上，人们经常观察到小龙虾爬上大型植物并以浮膜为食。
{"title":"Effects of the density of an invasive crayfish (Procambarus clarkii) on pelagic and surface microalgae in a Mediterranean wetland","authors":"F. Gherardi, L. Lazzara","doi":"10.1127/0003-9136/2006/0165-0401","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0401","url":null,"abstract":"To understand the relationship between the density of an introduced crayfish species (P. clarkii) and the abundance and composition of pelagic and surface microalgae (hereafter referred to as phytoplankton and phytoneuston, respectively) we ran an in situ experiment in a Mediterranean wetland. In May 2004, we delimited six 10 x 7m areas along a channel in the \"Padule di Fucecchio\" (Italy). Each area was randomly chosen to host crayfish populations at either low (1 crayfish/m 2 ) or high densities (14 crayfish/m 2 ). Phytoplankton and phytoneuston samplings were conducted in August and in September 2004, corresponding to the periods in which the highest and the lowest numbers of free-moving crayfish were found, respectively, during the lentic phase of the water regime. Results showed that (1) phytoneuston biomass, composed of cyanobacteria and, to a lesser extent, of euglenoids, was strongly affected by the presence of dense populations of P. clarkii in August; (2) crayfish seemed to modify the composition of microalgal communities; (3) these effects were not accompanied by significant differences between experimental areas in water chemistry and temperature; (4) physico-chemical measures highly varied with sampling periods along with a change in phytoplankton and phytoneuston abundance; and (5) high crayfish densities did not to exert any measurable effect on phytoplankton abundance. The decrease of phytoneuston may be the result of top-down effects of crayfish removing invertebrate grazers or, most likely, of direct grazing of crayfish. Indeed, crayfish were often observed climbing on macrophytes and feeding on the floating film.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80993115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0415
M. Jocqué, K. Martens, B. Riddoch, L. Brendonck
Abstract: Rock pools on granite outcrops occur worldwide and are poorly studied,despite their intrinsic biological interest. In semi-arid Botswana, such habitats occurmainly on the granite outcrops in the southwestern Hardveld zone. To date, studies onthese systems have focused mainly on individual species or particular interactions. Bymeans of frequent sampling (every other day) during an entire wet phase (hydrocycle),we attempted to get a time integrated overview of invertebrate species composition ina set of 18 rock pools from two clusters (meta-communities).A faunal list is presentedand described. Rock pool species were separated in permanent and ephemeral inhabi-tants, based on their strategy to survive or escape the frequent dry phases of their habi-tat, respectively. A new chydorid species, four new turbellarian taxa and two new ost-racod species were discovered. All new taxa were permanent inhabitants, illustratingthe need for more intense and time-integrated studies of these ephemeral systems andespecially the permanent residents with specific adaptations to the vagaries of theirvariable habitat. The best sampling strategy to assess species richness in these rockpool systems is to randomly sample three to four pools in a cluster, each in the finalphase of their hydrocycle.Key words: rock pool, ephemeral, fauna, sampling.
{"title":"Faunistics of ephemeral rock pools in southeastern Botswana","authors":"M. Jocqué, K. Martens, B. Riddoch, L. Brendonck","doi":"10.1127/0003-9136/2006/0165-0415","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0415","url":null,"abstract":"Abstract: Rock pools on granite outcrops occur worldwide and are poorly studied,despite their intrinsic biological interest. In semi-arid Botswana, such habitats occurmainly on the granite outcrops in the southwestern Hardveld zone. To date, studies onthese systems have focused mainly on individual species or particular interactions. Bymeans of frequent sampling (every other day) during an entire wet phase (hydrocycle),we attempted to get a time integrated overview of invertebrate species composition ina set of 18 rock pools from two clusters (meta-communities).A faunal list is presentedand described. Rock pool species were separated in permanent and ephemeral inhabi-tants, based on their strategy to survive or escape the frequent dry phases of their habi-tat, respectively. A new chydorid species, four new turbellarian taxa and two new ost-racod species were discovered. All new taxa were permanent inhabitants, illustratingthe need for more intense and time-integrated studies of these ephemeral systems andespecially the permanent residents with specific adaptations to the vagaries of theirvariable habitat. The best sampling strategy to assess species richness in these rockpool systems is to randomly sample three to four pools in a cluster, each in the finalphase of their hydrocycle.Key words: rock pool, ephemeral, fauna, sampling.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82926151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0365
K. Lívanský, J. Doucha, Hongjun Hu, Yeguang Li
A mathematical formula was derived for pCO 2 (partial pressure of dissolved carbon dioxide) in culture medium as a function of pH. The formula was verified in laboratory experiments with desorption of CO 2 from the mediuminto air which had been bubbled through a medium commonly used (ZARROUK'S recipe) for cultivation of the microalga Arthrospira (Spirulina). Concentration of sodium bicarbonate in the medium was 9 and 16.8 g l - 1 , respectively, at temperatures of 30 and 40 °C. The overall volumetric mass transfer coefficient K L a/V for CO 2 transfer from the medium into the gas phase increased about 2 % per 1°C increase of temperature and was not influenced by bicarbonate concentration in the medium. Mass balance of CO 2 in a suspension of Spirulina flowing in a layer of 8 mm thickness down an inclined cultivation surface was formulated and investigated theoretically, taking into account CO 2 consumption by the alga and CO 2 mass transfer from the suspension into the atmosphere. Calculations suggested that dissolved free (not chemically bound) carbon dioxide and concentration of bicarbonate ions in the suspension are practically in mutual chemical equilibrium. Mass flux of carbon dioxide from the suspension into the atmosphere is enhanced at increased suspension pH as a result of CO 2 formation from bicarbonate ions.
推导出了培养液中co2(溶解二氧化碳的分压)随ph值的函数的数学公式。该公式在实验室实验中得到了验证，该实验将co2从培养基中解吸到空气中，该空气通过一种常用的培养基(ZARROUK配方)来培养节螺旋藻(螺旋藻)。在温度为30℃和40℃时，培养基中碳酸氢钠的浓度分别为9和16.8 g l - 1。温度每升高1℃，CO 2从介质转移到气相的总体体积传质系数K L a/V增加约2%，且不受介质中碳酸氢盐浓度的影响。考虑藻类消耗的co2和从悬浮液向大气的co2传质，建立了螺旋藻悬浮液中沿倾斜培养面向下流动8 mm厚度层的co2质量平衡，并对其进行了理论研究。计算表明，悬浮液中溶解的游离(未化学结合的)二氧化碳和碳酸氢盐离子的浓度实际上处于相互的化学平衡状态。当悬浮液pH值增加时，由于碳酸氢盐离子形成二氧化碳，悬浮液中二氧化碳进入大气的质量通量增加。
{"title":"CO 2 partial pressure – pH relationships in the medium and relevance to CO 2 mass balance in outdoor open thin-layer Arthrospira ( Spirulina ) cultures","authors":"K. Lívanský, J. Doucha, Hongjun Hu, Yeguang Li","doi":"10.1127/0003-9136/2006/0165-0365","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0365","url":null,"abstract":"A mathematical formula was derived for pCO 2 (partial pressure of dissolved carbon dioxide) in culture medium as a function of pH. The formula was verified in laboratory experiments with desorption of CO 2 from the mediuminto air which had been bubbled through a medium commonly used (ZARROUK'S recipe) for cultivation of the microalga Arthrospira (Spirulina). Concentration of sodium bicarbonate in the medium was 9 and 16.8 g l - 1 , respectively, at temperatures of 30 and 40 °C. The overall volumetric mass transfer coefficient K L a/V for CO 2 transfer from the medium into the gas phase increased about 2 % per 1°C increase of temperature and was not influenced by bicarbonate concentration in the medium. Mass balance of CO 2 in a suspension of Spirulina flowing in a layer of 8 mm thickness down an inclined cultivation surface was formulated and investigated theoretically, taking into account CO 2 consumption by the alga and CO 2 mass transfer from the suspension into the atmosphere. Calculations suggested that dissolved free (not chemically bound) carbon dioxide and concentration of bicarbonate ions in the suspension are practically in mutual chemical equilibrium. Mass flux of carbon dioxide from the suspension into the atmosphere is enhanced at increased suspension pH as a result of CO 2 formation from bicarbonate ions.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82395512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0339
E. Hlaváčová, M. Rulík, L. Čáp, V. Mach
Greenhouse gas emissions from a small lowland stream in the Czech Republic were quantified using three methods. Emissions from the sediments measured with the static chamber method averaged 1.0 ′ 0.1 g CO 2 m - 2 d - 1 , 6.5 ′ 1.5 mg CH 4 m - 2 d - 1 and 0.31 ′ 0.04mg N 2 O m - 2 d - 1 , while calculated fluxes of gases across the air-water interface were much higher, in average 9.1 ′ 0.7 g CO 2 m - 2 d - 1 , 39.2 ′ 3.6mg CH 4 m - 2 d - 1 and 10.4 ′ 1.6 mg N 2 O m - 2 d - 1 . In addition, emissions measured using the floating chamber method averaged 3.7 ′ 0.3 g CO 2 m - 2 d - 1 , 16.0 ′ 3.4 mg CH 4 m - 2 d - 1 and 1.7 ′ 0.2 mg N 2 O m - 2 d - 1 . No relationship between temperature and gas emissions into the atmosphere was found. Gas fluxes across the air-water interface were significantly correlated with surface water concentrations, but emissions from the sediments showed no relationship with those concentrations in either the surface or interstitial water. Regardless of the method used, our results suggest that the Sitka stream is a source of gases into the atmosphere, and losses of carbon and nitrogen such as the fluxes of these greenhouse gases out into the ecosystem can participate significantly in river self-purification.
使用三种方法对捷克共和国一个小的低地河流的温室气体排放进行了量化。排放的沉积物测量静态室方法平均为1.0的0.1 g CO 2 m - 2 d - 1, 6.5的1.5毫克CH 4 m - 2 d - 1和0.31的0.04毫克N 2 O m - 2 d - 1,而通量计算空气与气体的界面都高得多,平均9.1的0.7 g CO 2 m - 2 d - 1, 39.2的3.6毫克CH 4 m - 2 d - 1和10.4的1.6毫克N 2 O m - 2 d - 1。此外，使用浮动室法测量的排放量平均为3.7 ' 0.3 g CO 2 m - 2 d - 1, 16.0 ' 3.4 mg CH 4 m - 2 d - 1和1.7 ' 0.2 mg N 2o m - 2 d - 1。没有发现温度和气体排放到大气中的关系。通过空气-水界面的气体通量与地表水浓度显著相关，但沉积物的排放与地表水或间隙水的浓度没有关系。无论采用何种方法，我们的研究结果表明，锡特卡河是大气中气体的一个来源，碳和氮的损失，如这些温室气体进入生态系统的通量，可以显著参与河流的自净化。
{"title":"Greenhouse gas (CO2, CH4, N2O) emissions to the atmosphere from a small lowland stream in Czech Republic","authors":"E. Hlaváčová, M. Rulík, L. Čáp, V. Mach","doi":"10.1127/0003-9136/2006/0165-0339","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0339","url":null,"abstract":"Greenhouse gas emissions from a small lowland stream in the Czech Republic were quantified using three methods. Emissions from the sediments measured with the static chamber method averaged 1.0 ′ 0.1 g CO 2 m - 2 d - 1 , 6.5 ′ 1.5 mg CH 4 m - 2 d - 1 and 0.31 ′ 0.04mg N 2 O m - 2 d - 1 , while calculated fluxes of gases across the air-water interface were much higher, in average 9.1 ′ 0.7 g CO 2 m - 2 d - 1 , 39.2 ′ 3.6mg CH 4 m - 2 d - 1 and 10.4 ′ 1.6 mg N 2 O m - 2 d - 1 . In addition, emissions measured using the floating chamber method averaged 3.7 ′ 0.3 g CO 2 m - 2 d - 1 , 16.0 ′ 3.4 mg CH 4 m - 2 d - 1 and 1.7 ′ 0.2 mg N 2 O m - 2 d - 1 . No relationship between temperature and gas emissions into the atmosphere was found. Gas fluxes across the air-water interface were significantly correlated with surface water concentrations, but emissions from the sediments showed no relationship with those concentrations in either the surface or interstitial water. Regardless of the method used, our results suggest that the Sitka stream is a source of gases into the atmosphere, and losses of carbon and nitrogen such as the fluxes of these greenhouse gases out into the ecosystem can participate significantly in river self-purification.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83696307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0383
C. Padilla, S. Sanz-Alférez, F. F. Campo
The Santillana reservoir, a drinking-water supply in the central part of Spain, was monitored weekly from June to November of 1997 for cyanobacteria and microcystins (MCs) in plankton biomass. Several blooms appeared, some of them with a high MC content. Large changes in both phytoplankton biomass and MCs were observed in a short time period, but not in a concomitant way. We have characterised one Microcystis strain, UAM97, that seemed to dominate a bloom, and with an unusually high MC content. The results obtained strongly indicate that Microcystis UAM97 is a M. flos-aquae strain, containing 4 major MCs: MC-LR, MC-LF, MC-LW, and MC-LY. Species assignment is supported by morphology and molecular criteria. Molecular identification was based on comparison of 16S-23S rDNA internal transcribed spacer (ITS) sequences from Microcystis UAM97 and three other collection Microcystis strains. MCs were characterised by amino acid analysis and combined high performance liquid chromatography and mass spectrometry (HPLC/MS) techniques. This report is the first on a M. flos-aquae strain dominating a toxic bloom in Spanish waterbodies.
{"title":"Toxin characterisation and identification of a Microcystis flos-aquae strain from a Spanish drinking-water reservoir","authors":"C. Padilla, S. Sanz-Alférez, F. F. Campo","doi":"10.1127/0003-9136/2006/0165-0383","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0383","url":null,"abstract":"The Santillana reservoir, a drinking-water supply in the central part of Spain, was monitored weekly from June to November of 1997 for cyanobacteria and microcystins (MCs) in plankton biomass. Several blooms appeared, some of them with a high MC content. Large changes in both phytoplankton biomass and MCs were observed in a short time period, but not in a concomitant way. We have characterised one Microcystis strain, UAM97, that seemed to dominate a bloom, and with an unusually high MC content. The results obtained strongly indicate that Microcystis UAM97 is a M. flos-aquae strain, containing 4 major MCs: MC-LR, MC-LF, MC-LW, and MC-LY. Species assignment is supported by morphology and molecular criteria. Molecular identification was based on comparison of 16S-23S rDNA internal transcribed spacer (ITS) sequences from Microcystis UAM97 and three other collection Microcystis strains. MCs were characterised by amino acid analysis and combined high performance liquid chromatography and mass spectrometry (HPLC/MS) techniques. This report is the first on a M. flos-aquae strain dominating a toxic bloom in Spanish waterbodies.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91363106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0289
M. Sterken, K. Sabbe, A. Chepstow-Lusty, M. Frogley, K. Vanhoutte, E. Verleyen, A. Cundy, W. Vyverman
A quantitative diatom analysis was carried out on a sediment core from the small infilled lake basin of Marcacocha (Cuzco-region, SE Peru), in order to reconstruct environmental changes between 800 and 1850 AD. Five stratigraphical zones were distinguished by means of constrained cluster analysis. Very few diatoms were present between 790 and 1070 AD, probably reflecting dry and cool conditions, at a time when anthropogenic impact was limited around the basin. The transition at ca. 1070 AD was the most pronounced, and corresponded with a marked shift towards higher temperatures, as deduced from plant macroremains and the pollen record. This coincided with a sudden climate shift from cold and dry conditions towards warmer and even drier conditions, as recorded elsewhere in tropical South America. Between 1070 and 1650 AD diatoms (mainly the genus Epithemia Ktzing) became more abundant, together with charophyte oospores, suggesting the existence of a stable, shallow lake. The transition in diatom composition and abundances at ca. 1650 AD, with peaks centered on 1700 AD, lag behind the start of the Little Ice Age (around 1490-1530 AD), though match increased cooling at the end of the 17th and early 18th century as recorded in Peruvian ice cores. This could be caused by a threshold that was passed after the lake level had lowered sufficiently due to a cooling and drying climate, as well as infilling processes. Further transitions in the diatom community may be interpreted less in terms of climatic change, but as increasing sensitivity to local environmental changes, such as a lake level decrease and lake infilling. A hiatus in diatom abundance observed between ca. 1750 and 1810 AD, could be associated with increasing colonization of Juncaceae around the lake margin and rapid infilling, possibly linked to the construction of drainage canals clearly visible today. The final stage of infilling occurred after ca. 1845 AD, with complete colonization of the remaining lake surface by Juncaceae, with further accumulation of peats.
{"title":"Hydrological and land-use changes in the Cuzco region (Cordillera Oriental, South East Peru) during the last 1200 years: a diatom-based reconstruction","authors":"M. Sterken, K. Sabbe, A. Chepstow-Lusty, M. Frogley, K. Vanhoutte, E. Verleyen, A. Cundy, W. Vyverman","doi":"10.1127/0003-9136/2006/0165-0289","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0289","url":null,"abstract":"A quantitative diatom analysis was carried out on a sediment core from the small infilled lake basin of Marcacocha (Cuzco-region, SE Peru), in order to reconstruct environmental changes between 800 and 1850 AD. Five stratigraphical zones were distinguished by means of constrained cluster analysis. Very few diatoms were present between 790 and 1070 AD, probably reflecting dry and cool conditions, at a time when anthropogenic impact was limited around the basin. The transition at ca. 1070 AD was the most pronounced, and corresponded with a marked shift towards higher temperatures, as deduced from plant macroremains and the pollen record. This coincided with a sudden climate shift from cold and dry conditions towards warmer and even drier conditions, as recorded elsewhere in tropical South America. Between 1070 and 1650 AD diatoms (mainly the genus Epithemia Ktzing) became more abundant, together with charophyte oospores, suggesting the existence of a stable, shallow lake. The transition in diatom composition and abundances at ca. 1650 AD, with peaks centered on 1700 AD, lag behind the start of the Little Ice Age (around 1490-1530 AD), though match increased cooling at the end of the 17th and early 18th century as recorded in Peruvian ice cores. This could be caused by a threshold that was passed after the lake level had lowered sufficiently due to a cooling and drying climate, as well as infilling processes. Further transitions in the diatom community may be interpreted less in terms of climatic change, but as increasing sensitivity to local environmental changes, such as a lake level decrease and lake infilling. A hiatus in diatom abundance observed between ca. 1750 and 1810 AD, could be associated with increasing colonization of Juncaceae around the lake margin and rapid infilling, possibly linked to the construction of drainage canals clearly visible today. The final stage of infilling occurred after ca. 1845 AD, with complete colonization of the remaining lake surface by Juncaceae, with further accumulation of peats.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79159779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-03-01DOI: 10.1127/0003-9136/2006/0165-0355
N. Kamjunke, Chris Bohn, J. Grey
We compared growth rates and efficiencies of pelagic bacteria from an extremely acidic mining lake (pH 2.6, mean depth 4.6 m) supplied with different sources of carbon: (1) excreted by phytoplankton, (2) derived from benthic algae, (3) entering the lake via ground water, and (4) leached from leaf litter. Bacteria exhibited high growth rate and efficiency on exudates of pelagic and benthic algae. In contrast, they showed a lower growth rate and efficiency with organic carbon from ground water, and grew at a very high rate but a very low efficiency on leaf leachate. Results from stable isotope analyses indicate a greater importance of benthic exudates and leaf leachate for bacteria in the epilimnion, and a higher impact of ground water sources in the hypolimnion. Given the magnitude of differential source inputs into the lake, we suggest that benthic primary production was the most important carbon source for pelagic bacteria. The benthic-pelagic coupling seems to be more relevant in this shallow acidic lake with low pelagic carbon dioxide concentrations than in neutral lakes.
{"title":"Utilisation of dissolved organic carbon from different sources by pelagic bacteria in an acidic mining lake","authors":"N. Kamjunke, Chris Bohn, J. Grey","doi":"10.1127/0003-9136/2006/0165-0355","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0165-0355","url":null,"abstract":"We compared growth rates and efficiencies of pelagic bacteria from an extremely acidic mining lake (pH 2.6, mean depth 4.6 m) supplied with different sources of carbon: (1) excreted by phytoplankton, (2) derived from benthic algae, (3) entering the lake via ground water, and (4) leached from leaf litter. Bacteria exhibited high growth rate and efficiency on exudates of pelagic and benthic algae. In contrast, they showed a lower growth rate and efficiency with organic carbon from ground water, and grew at a very high rate but a very low efficiency on leaf leachate. Results from stable isotope analyses indicate a greater importance of benthic exudates and leaf leachate for bacteria in the epilimnion, and a higher impact of ground water sources in the hypolimnion. Given the magnitude of differential source inputs into the lake, we suggest that benthic primary production was the most important carbon source for pelagic bacteria. The benthic-pelagic coupling seems to be more relevant in this shallow acidic lake with low pelagic carbon dioxide concentrations than in neutral lakes.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90553195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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