Larissa Faria, F. A. Frehse, T. V. Occhi, B. Carvalho, Daniel Vicente Pupo, S. T. Disaró, J. Vitule
Abstract: Aim This paper aims to concatenate and update the records of non-native species in a subtropical River, in Southern Brazil, warning about their possible impacts in this and other water bodies. Methods Monitoring was carried out in the Guaraguaçu River, the largest River of the Paraná coastal plain, located in the Atlantic Rainforest biome. Fishes were sampled in two periods: from 2002 to 2007 (monthly) and from 2016 to 2018 (semiannually), and the other organisms were collected in isolated samplings. Results The monitoring recorded the presence of six non-native species of animals in this River – four species of fish (Clarias gariepinus, Ictalurus punctatus, Oreochromis niloticus and Salminus brasiliensis), one invertebrate (Macrobrachium rosenbergii) and one foraminifera (Ammoglobigerina globigeriniformis) introduced by escapes from aquaculture, sport fishing and ballast water. These introductions are problematic because they have the potential to impact upon the endangered native species in the River through predation, competition or novel diseases. Conclusions In Guaraguaçu River the increasing number of introductions is worrying because these species have in common a set of traits that turns them into potential invaders. It is of great importance to keep monitoring their populations in order to detect and minimize their negative impacts on native biota, once there is a conservation unit in the region (Guaraguaçu Ecological Station), with the aim to protect the environment in its pristine condition.
{"title":"Occurrence of non-native species in a subtropical coastal River, in Southern Brazil","authors":"Larissa Faria, F. A. Frehse, T. V. Occhi, B. Carvalho, Daniel Vicente Pupo, S. T. Disaró, J. Vitule","doi":"10.1590/s2179-975x2320","DOIUrl":"https://doi.org/10.1590/s2179-975x2320","url":null,"abstract":"Abstract: Aim This paper aims to concatenate and update the records of non-native species in a subtropical River, in Southern Brazil, warning about their possible impacts in this and other water bodies. Methods Monitoring was carried out in the Guaraguaçu River, the largest River of the Paraná coastal plain, located in the Atlantic Rainforest biome. Fishes were sampled in two periods: from 2002 to 2007 (monthly) and from 2016 to 2018 (semiannually), and the other organisms were collected in isolated samplings. Results The monitoring recorded the presence of six non-native species of animals in this River – four species of fish (Clarias gariepinus, Ictalurus punctatus, Oreochromis niloticus and Salminus brasiliensis), one invertebrate (Macrobrachium rosenbergii) and one foraminifera (Ammoglobigerina globigeriniformis) introduced by escapes from aquaculture, sport fishing and ballast water. These introductions are problematic because they have the potential to impact upon the endangered native species in the River through predation, competition or novel diseases. Conclusions In Guaraguaçu River the increasing number of introductions is worrying because these species have in common a set of traits that turns them into potential invaders. It is of great importance to keep monitoring their populations in order to detect and minimize their negative impacts on native biota, once there is a conservation unit in the region (Guaraguaçu Ecological Station), with the aim to protect the environment in its pristine condition.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67852132","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}
Abstract: Aim Reservoirs are an increasingly common type of aquatic ecosystem in countries where hydropower is a dominant energy source. Understanding the functioning of these systems is essential to establish monitoring strategies or priorities for their use. The main goal of this study was to test for the presence of longitudinal gradients in reservoirs. Methods We gathered data along the main axes of 17 tropical reservoirs to test the relationship between different ecological indicators (e.g., turbidity, nutrient concentrations, and phytoplankton abundance) and distance to the dam. After, we tested whether the strengths of longitudinal gradients were related to a set of explanatory variables (occurrence in a reservoir cascade, presence of tributaries near the dam, land-use, morphology and reservoir age). Results We did not find significant relationships between our set of ecological indicators and distance to the dam and the strengths of these relationships were not consistently predicted by the explanatory variables. However, different indicators suggested patterns consistent with expectations. Conclusion The distance to the dam is not a consistent predictor of the spatial variation of different limnological variables in tropical reservoirs, highlighting a high degree of context-dependency.
{"title":"Revisiting the concept of longitudinal gradients in reservoirs","authors":"F. M. Carneiro, L. M. Bini","doi":"10.1590/s2179-975x1319","DOIUrl":"https://doi.org/10.1590/s2179-975x1319","url":null,"abstract":"Abstract: Aim Reservoirs are an increasingly common type of aquatic ecosystem in countries where hydropower is a dominant energy source. Understanding the functioning of these systems is essential to establish monitoring strategies or priorities for their use. The main goal of this study was to test for the presence of longitudinal gradients in reservoirs. Methods We gathered data along the main axes of 17 tropical reservoirs to test the relationship between different ecological indicators (e.g., turbidity, nutrient concentrations, and phytoplankton abundance) and distance to the dam. After, we tested whether the strengths of longitudinal gradients were related to a set of explanatory variables (occurrence in a reservoir cascade, presence of tributaries near the dam, land-use, morphology and reservoir age). Results We did not find significant relationships between our set of ecological indicators and distance to the dam and the strengths of these relationships were not consistently predicted by the explanatory variables. However, different indicators suggested patterns consistent with expectations. Conclusion The distance to the dam is not a consistent predictor of the spatial variation of different limnological variables in tropical reservoirs, highlighting a high degree of context-dependency.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67826106","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}
L. Virgilio, Cleyton Holanda de Brito, M. S. Suçuarana, L. Vieira
Aims: To evaluate the effects of replacing riparian vegetation with pasture in the diet of Apistogramma agassizii and Aequidens tetramerus. Methods: The study was carried out in the municipality of Senador Guiomar, Acre. We sampled three streams divided into three stretches each (100 m), bordered by forest, pasture, and both forest and pasture (edge). Quarterly collections using fishnets were performed between January and October 2008. Results: The species A. agassizii had a diet based on the consumption of adult insects in stretches of forest, different from the pasture environment, in which the consumption of insect larvae was higher. In the diet of A. tetramerus, the most important item was insect larvae in all environments, mainly in the pasture. We found low amplitude of trophic niche for A. agassizii in the forest environment, due to the consumption of adult insects, and for A. tetramerus in the pasture, due to the consumption of insect larvae. In the pasture areas, we found no difference between the items consumed by the species, which showed a high trophic niche overlap, influenced by the consumption of Diptera larvae. Conclusion: Thus, we show that allochthonous items, such as adult insects, are food resources indicative of riparian vegetation conservation and are important for both species, mainly A. agassizii. However, this item has been replaced by autochthonous items, such as Diptera larvae, in the A. agassizii diet and become predominant in the A. tetramerus diet as the riparian vegetation deteriorates.
{"title":"Forest fragmentation influences the diet of cichlids Apistogramma agassizii (Steindachner, 1875) and Aequidens tetramerus (Heckel, 1840) (Actinopterygii: Cichliformes) in streams of the Western Amazon","authors":"L. Virgilio, Cleyton Holanda de Brito, M. S. Suçuarana, L. Vieira","doi":"10.1590/s2179-975x2618","DOIUrl":"https://doi.org/10.1590/s2179-975x2618","url":null,"abstract":"Aims: To evaluate the effects of replacing riparian vegetation with pasture in the diet of Apistogramma agassizii and Aequidens tetramerus. Methods: The study was carried out in the municipality of Senador Guiomar, Acre. We sampled three streams divided into three stretches each (100 m), bordered by forest, pasture, and both forest and pasture (edge). Quarterly collections using fishnets were performed between January and October 2008. Results: The species A. agassizii had a diet based on the consumption of adult insects in stretches of forest, different from the pasture environment, in which the consumption of insect larvae was higher. In the diet of A. tetramerus, the most important item was insect larvae in all environments, mainly in the pasture. We found low amplitude of trophic niche for A. agassizii in the forest environment, due to the consumption of adult insects, and for A. tetramerus in the pasture, due to the consumption of insect larvae. In the pasture areas, we found no difference between the items consumed by the species, which showed a high trophic niche overlap, influenced by the consumption of Diptera larvae. Conclusion: Thus, we show that allochthonous items, such as adult insects, are food resources indicative of riparian vegetation conservation and are important for both species, mainly A. agassizii. However, this item has been replaced by autochthonous items, such as Diptera larvae, in the A. agassizii diet and become predominant in the A. tetramerus diet as the riparian vegetation deteriorates.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67853449","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}
W. Lázaro, E. S. Oliveira-Júnior, C. J. Silva, Solange Kimie Ikeda Castrillon, C. C. Muniz
Abstract: The dynamics of Pantanal is totally influenced by the flood pulse, which is, in part, a consequence of rainfall regime from the Amazon in the direction to the headlands and the lowlands where the water is retained, and the flood plain is formed. The impacts of climate change have not yet been measured for the Northern Pantanal (Pantanal of Cáceres), where it is the gateway to most Pantanal waters. Here, we have used rainfall, hydrology, and satellite imagery data to ascertain the possible rainfall patterns, water retention, and level of the Paraguay River over the past decades. Although a well-defined water pulse is found in the Northern Pantanal, over a 42-year historical series the number of days without precipitation has greatly increased, as well the loss of water mass in the landscape over the last 10 years specifically in during the drought season. Overall, nowadays the Northern Pantanal has 13% more days without rain than in the 60’s, and the water mass is 16% less during the drought season considering the last 10 years. These results show that nowadays the Pantanal is losing water and experiencing a more severe drought season than in the past. Regarding the physicochemical and biological cycles of the ecosystem, these changes can result in the loss of biodiversity, as well as the loss of ecosystem services, intrinsically linked to the flood pulse. Given that these losses have been aggravated by anthropogenic pressures (e.g. deforestation, erosion, hydroelectric power stations), the drafting of strategic plans for safeguarding wildlife and human populations, as well as agriculture, cattle raising, fisheries and the preservation of the people’s lifestyle in the Pantanal must be urgently implemented.
{"title":"Climate change reflected in one of the largest wetlands in the world: an overview of the Northern Pantanal water regime","authors":"W. Lázaro, E. S. Oliveira-Júnior, C. J. Silva, Solange Kimie Ikeda Castrillon, C. C. Muniz","doi":"10.1590/s2179-975x7619","DOIUrl":"https://doi.org/10.1590/s2179-975x7619","url":null,"abstract":"Abstract: The dynamics of Pantanal is totally influenced by the flood pulse, which is, in part, a consequence of rainfall regime from the Amazon in the direction to the headlands and the lowlands where the water is retained, and the flood plain is formed. The impacts of climate change have not yet been measured for the Northern Pantanal (Pantanal of Cáceres), where it is the gateway to most Pantanal waters. Here, we have used rainfall, hydrology, and satellite imagery data to ascertain the possible rainfall patterns, water retention, and level of the Paraguay River over the past decades. Although a well-defined water pulse is found in the Northern Pantanal, over a 42-year historical series the number of days without precipitation has greatly increased, as well the loss of water mass in the landscape over the last 10 years specifically in during the drought season. Overall, nowadays the Northern Pantanal has 13% more days without rain than in the 60’s, and the water mass is 16% less during the drought season considering the last 10 years. These results show that nowadays the Pantanal is losing water and experiencing a more severe drought season than in the past. Regarding the physicochemical and biological cycles of the ecosystem, these changes can result in the loss of biodiversity, as well as the loss of ecosystem services, intrinsically linked to the flood pulse. Given that these losses have been aggravated by anthropogenic pressures (e.g. deforestation, erosion, hydroelectric power stations), the drafting of strategic plans for safeguarding wildlife and human populations, as well as agriculture, cattle raising, fisheries and the preservation of the people’s lifestyle in the Pantanal must be urgently implemented.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67871017","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 : 2020-01-01DOI: 10.1590/s2179-975x10020020
A. Amado, R. M. Almeida, S. Cardoso, J. A. Santos, A. F. Camargo
{"title":"Editorial: Freshwater sustainability and aquatic ecology in a fast-changing world","authors":"A. Amado, R. M. Almeida, S. Cardoso, J. A. Santos, A. F. Camargo","doi":"10.1590/s2179-975x10020020","DOIUrl":"https://doi.org/10.1590/s2179-975x10020020","url":null,"abstract":"","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67822892","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}
É. A. Gubiani, Renata Ruaro, Vinícius Ricardo Ribeiro, Úrsula Morgana Gomes de Santa Fé
Aim: In this paper we present a scientometric analysis aimed at to assess and quantify the contribution of Le Cren’s condition factor and the main ideas advanced by ‘Le Cren, 1951’ to studies on the health of individuals or populations in aquatic environments. Specifically, we addressed the following questions: (i) what are the temporal and spatial citation trends of ‘Le Cren, 1951’?; (ii) Which journals cited ‘Le Cren, 1951’ most frequently?; (iii) In which types of aquatic environments and organisms have Le Cren’s condition factor been most commonly applied?; (iv) Which of the main applications addressed in ‘Le Cren, 1951’ have been most frequently used by fisheries scientists?; (v) Which of the methods (i.e., Quételet’s index or body mass index, Fulton’s condition factor, Le Cren’s condition factor, relative weight, residual index and scaled mass index) used to estimate condition factor identified in the papers that cited ‘Le Cren, 1951’ have been most frequently used? In addition, the main criticisms of the use of the relative condition factor are discussed. Methods: We carried out a scientometric analysis on the papers published from 1951 to December 2015 that cited Le Cren’s article. The papers were obtained from the Thomson Reuters database (ISI Web of Knowledge, apps.isiknowledge.com) in May 2016. Results: In total, 1128 papers were assessed. The number of citations increased significantly over time. Most citations occurred in two journals (Journal of Fish Biology and Journal of Applied Ichthyology). Most of papers were carried out in marine environments. In addition, we show that Le Cren’s paper has been cited mainly in articles that estimate the condition factor or the weight-length relationship of populations. Finally, we emphasize that the relative condition factor proposed by Le Cren in 1951 is still the main method used to estimate the body condition of an individual or population. Conclusions: Le Cren’s significant contribution to animal well-being is undeniable, and we emphasize that among the methods identified in the papers that cited ‘Le Cren, 1951’ that estimated body condition, the relative condition factor proposed by Le Cren in 1951 is still the most commonly used method.
目的:本文提出了一种科学计量分析方法，旨在评估和量化Le Cren条件因子对水生环境中个体或群体健康研究的贡献和Le Cren, 1951年提出的主要思想。具体来说，我们解决了以下问题:(i)《Le Cren, 1951》的时空被引趋势是什么?哪些期刊最常引用《Le crean, 1951》?勒克林条件因子最常应用于哪些类型的水生环境和生物?渔业科学家最常使用《1951年勒克伦》中提到的哪些主要应用?(v)在引用“Le Cren, 1951”的论文中，用来估计条件因子的方法(即qusametet指数或体重指数、Fulton条件因子、Le Cren条件因子、相对重量、残差指数和比例质量指数)中，最常用的是哪一种?此外，还讨论了使用相对条件因子的主要批评。方法:对1951年至2015年12月发表的引用Le Cren文章的论文进行科学计量学分析。这些论文于2016年5月从汤森路透数据库(ISI Web of Knowledge, apps.isiknowledge.com)获得。结果:共评估论文1128篇。随着时间的推移，被引用的次数显著增加。大多数引用出现在两种期刊上(Journal of Fish Biology和Journal of Applied鱼类学)。大多数论文是在海洋环境中进行的。此外，我们发现Le Cren的论文主要被引用于估计种群条件因子或权重-长度关系的文章中。最后，我们强调，Le Cren于1951年提出的相对条件因子仍然是估计个体或群体身体状况的主要方法。结论:Le Cren对动物福利的重大贡献是不可否认的，我们强调，在引用Le Cren, 1951的论文中确定的估计身体状况的方法中，Le Cren在1951年提出的相对条件因子仍然是最常用的方法。
{"title":"Relative condition factor: Le Cren's legacy for fisheries science","authors":"É. A. Gubiani, Renata Ruaro, Vinícius Ricardo Ribeiro, Úrsula Morgana Gomes de Santa Fé","doi":"10.1590/s2179-975x13017","DOIUrl":"https://doi.org/10.1590/s2179-975x13017","url":null,"abstract":"Aim: In this paper we present a scientometric analysis aimed at to assess and quantify the contribution of Le Cren’s condition factor and the main ideas advanced by ‘Le Cren, 1951’ to studies on the health of individuals or populations in aquatic environments. Specifically, we addressed the following questions: (i) what are the temporal and spatial citation trends of ‘Le Cren, 1951’?; (ii) Which journals cited ‘Le Cren, 1951’ most frequently?; (iii) In which types of aquatic environments and organisms have Le Cren’s condition factor been most commonly applied?; (iv) Which of the main applications addressed in ‘Le Cren, 1951’ have been most frequently used by fisheries scientists?; (v) Which of the methods (i.e., Quételet’s index or body mass index, Fulton’s condition factor, Le Cren’s condition factor, relative weight, residual index and scaled mass index) used to estimate condition factor identified in the papers that cited ‘Le Cren, 1951’ have been most frequently used? In addition, the main criticisms of the use of the relative condition factor are discussed. Methods: We carried out a scientometric analysis on the papers published from 1951 to December 2015 that cited Le Cren’s article. The papers were obtained from the Thomson Reuters database (ISI Web of Knowledge, apps.isiknowledge.com) in May 2016. Results: In total, 1128 papers were assessed. The number of citations increased significantly over time. Most citations occurred in two journals (Journal of Fish Biology and Journal of Applied Ichthyology). Most of papers were carried out in marine environments. In addition, we show that Le Cren’s paper has been cited mainly in articles that estimate the condition factor or the weight-length relationship of populations. Finally, we emphasize that the relative condition factor proposed by Le Cren in 1951 is still the main method used to estimate the body condition of an individual or population. Conclusions: Le Cren’s significant contribution to animal well-being is undeniable, and we emphasize that among the methods identified in the papers that cited ‘Le Cren, 1951’ that estimated body condition, the relative condition factor proposed by Le Cren in 1951 is still the most commonly used method.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67826063","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}
Abstract: In this review, we present information about the presence of trace elements on streams and the consequences related to the increase of these chemical elements on aquatic systems. Although several studies on trace elements contamination in aquatic environments are conducted on point sources, non-point sources also have a high potential to contaminate water bodies. Some trace elements are important for the development of an organism. However, even essential elements, in high concentrations, may be toxic to aquatic organisms. In some cases, trace elements may accumulate and be transferred along food webs, generating changes in the structure and functioning of terrestrial ecosystems. The phytoremediation techniques could be an important tool in reducing the problems generated by trace elements. Thus, understanding the effects generated by the increase of trace elements concentrations on aquatic ecosystems becomes important to help public managers to apply solutions for the mitigation of this chemical pollution on natural resources.
{"title":"Stream contamination by trace elements: biota incorporation and phytoremediation","authors":"R. C. Loureiro, L. U. Hepp","doi":"10.1590/s2179-975x2219","DOIUrl":"https://doi.org/10.1590/s2179-975x2219","url":null,"abstract":"Abstract: In this review, we present information about the presence of trace elements on streams and the consequences related to the increase of these chemical elements on aquatic systems. Although several studies on trace elements contamination in aquatic environments are conducted on point sources, non-point sources also have a high potential to contaminate water bodies. Some trace elements are important for the development of an organism. However, even essential elements, in high concentrations, may be toxic to aquatic organisms. In some cases, trace elements may accumulate and be transferred along food webs, generating changes in the structure and functioning of terrestrial ecosystems. The phytoremediation techniques could be an important tool in reducing the problems generated by trace elements. Thus, understanding the effects generated by the increase of trace elements concentrations on aquatic ecosystems becomes important to help public managers to apply solutions for the mitigation of this chemical pollution on natural resources.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67851183","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}
L. E. Fontana, R. M. Restello, T. L. Sausen, L. U. Hepp
Abstract Aim We evaluated the effect of the presence of Hovenia dulcis Thunb. (Rhamnaceae) in riparian zones on the organic matter dynamics of small subtropical streams. Methods We conducted this study in three subtropical Atlantic Forest streams with different densities of H. dulcis in riparian vegetation located in southern Brazil. In each stream, we quantified the input of allochthonous organic matter for one year using buckets (area: 0.04 m2/bucket) suspended about 1 m from the streambed in three different sections (15 buckets/stretch = 45 buckets/stream). Monthly, the plant material retained in the buckets was collected individually, dried (40±5 °C/72 h), identified (native litter together and H. dulcis litter alone) and weighed. Results The largest input of native organic matter occurred during the winter months (~55 g.m-2), ranging from ~31 g.m-2 (summer) to ~46 g.m-2 (spring) over the year. The input of H. dulcis organic matter was concentrated in the autumn (~56 g.m-2) and summer (~28 g.m-2), being scarce in the other seasons (~3 g.m-2 in the spring and winter). Only the contribution of native organic matter was associated with precipitation. Contrary to that observed with native vegetation (input of organic matter related with rainfall), H. dulcis input was related to the phenology of the species, which is deciduous, with leaf fall strongly marked, occurring especially during the autumn. Conclusions When present at high densities (dominant), the presence of H. dulcis in riparian stream vegetation makes the supply of allochthonous plant resources scarce at some periods of the year, altering the energy availability in these ecosystems and, potentially, the functioning of subtropical streams.
【摘要】目的评价黄毒菊的作用。(鼠李科)河岸带对亚热带小溪流有机质动态的影响。方法在巴西南部河岸植被中，对三条不同密度的热带大西洋森林溪流进行了研究。在每条河流中，我们在三个不同的区域(15个桶/段= 45个桶/条)中，使用悬挂在离河床约1米的桶(面积:0.04 m2/桶)，量化了一年的外来有机质输入。每月单独收集桶中保留的植物材料，在40±5°C/72 h下干燥，鉴定(包括原生凋落物和单独的水杨凋落物)并称重。结果全年天然有机质输入量最大的季节为冬季(~55 g m-2)，夏季为~31 g m-2，春季为~46 g m-2。水杨有机质的输入主要集中在秋季(~56 g - m-2)和夏季(~28 g - m-2)，其他季节较少(春、冬季~3 g - m-2)。只有天然有机质的贡献与降水有关。与原生植被(有机质输入与降雨有关)相反，水杨的输入与该物种的物候有关，为落叶，落叶明显，尤其发生在秋季。结论:当密度较高(优势)时，水蛭在河岸河流植被中的存在使外来植物资源在一年中的某些时期供应短缺，从而改变了这些生态系统的能量有效性，并可能改变亚热带河流的功能。
{"title":"Plant species invasion effects on litter dynamics in subtropical streams","authors":"L. E. Fontana, R. M. Restello, T. L. Sausen, L. U. Hepp","doi":"10.1590/s2179-975x8219","DOIUrl":"https://doi.org/10.1590/s2179-975x8219","url":null,"abstract":"Abstract Aim We evaluated the effect of the presence of Hovenia dulcis Thunb. (Rhamnaceae) in riparian zones on the organic matter dynamics of small subtropical streams. Methods We conducted this study in three subtropical Atlantic Forest streams with different densities of H. dulcis in riparian vegetation located in southern Brazil. In each stream, we quantified the input of allochthonous organic matter for one year using buckets (area: 0.04 m2/bucket) suspended about 1 m from the streambed in three different sections (15 buckets/stretch = 45 buckets/stream). Monthly, the plant material retained in the buckets was collected individually, dried (40±5 °C/72 h), identified (native litter together and H. dulcis litter alone) and weighed. Results The largest input of native organic matter occurred during the winter months (~55 g.m-2), ranging from ~31 g.m-2 (summer) to ~46 g.m-2 (spring) over the year. The input of H. dulcis organic matter was concentrated in the autumn (~56 g.m-2) and summer (~28 g.m-2), being scarce in the other seasons (~3 g.m-2 in the spring and winter). Only the contribution of native organic matter was associated with precipitation. Contrary to that observed with native vegetation (input of organic matter related with rainfall), H. dulcis input was related to the phenology of the species, which is deciduous, with leaf fall strongly marked, occurring especially during the autumn. Conclusions When present at high densities (dominant), the presence of H. dulcis in riparian stream vegetation makes the supply of allochthonous plant resources scarce at some periods of the year, altering the energy availability in these ecosystems and, potentially, the functioning of subtropical streams.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67871277","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}
M. R. Santos, V. Saito, P. A. Z. Pamplin, A. A. Pereira, A. Fonseca-Gessner
Aim: To test how different taxonomic and functional groups of aquatic insects from high-altitude streams respond to environmental and spatial gradients at multiple scales in Southeast of Brazil. Methods: Specimens were collected in 26 high-altitude streams distributed over a gradient of previously defined environmental quality. The taxonomic identification was made at the genus level and the functional classification was based on traits of flight capacity and pollution tolerance compiled from specific literature. We obtained local in situ data (limnological, sediments, and organic matter), as well as calculated land use at the riparian and drainage basin scale. A variation partitioning approach was used to explain species composition based on different response matrices deconstructed by both taxonomic groups and functional traits. The explanatory matrices encompassed environmental variables at three spatial scales and spatial variables extracted from Principal Components of Neighbor Matrices analysis. A linear model was applied to verify the possible correlation between spatial and environmental components. Results: The contribution of the spatial and environmental components varied strongly between taxonomic and functional groups. For taxonomic groups, the pure environmental component was more important for Odonata and Trichoptera, while spatial variables were more important for Diptera (non-Chironomidae) and Chironomidae, Coleoptera, Ephemeroptera, Plecoptera and Megaloptera. The sensitive groups with good flight capacity showed a greater environmental signature while the tolerant groups with low flight capacity had a greater spatial signature. Moreover, the important variables for explaining community variation were from different spatial scale (local, riparian and watershed) depending either on the analyzed taxonomic or on functional groups. However, a general effect of forests was found in several groups. Conclusions: It 2 Santos, M.R. et al. Acta Limnologica Brasiliensia, 2020, vol. 32, e20 to relate to both spatial and environmental factors concomitantly. In this sense, communities strongly affected by spatially structured environmental pressures would be expected to be strongly related to the spatial distance among sites as well. To disentangle the correlated effects of environmental and spatial variation on community composition, statistical techniques to partition the explained proportion of community variation were proposed (Borcard et al., 1992), becoming important tools in metacommunity studies. Moreover, the spatial scale used will be an important element to detect ecological patterns, both related to environmental and spatial factors (Leibold et al., 2004; Heino et al., 2017; Tonkin et al., 2017a). This premise is relevant mainly in continental aquatic environments in which many streams constitute networks (Frissell et al., 1986; Finn et al., 2011; Tonkin et al., 2017b) that behave like islands disconnected by the fragmented matrix
目的:研究巴西东南部高海拔溪流中不同分类和功能类群对环境和空间梯度的响应。方法:在26条高海拔河流中采集标本，这些河流分布在先前定义的环境质量梯度上。分类鉴定在属水平上进行，功能分类依据文献编制的飞行能力和污染耐受性状进行。我们获得了当地的原位数据(湖泊、沉积物和有机质)，并计算了河岸和流域尺度的土地利用。采用变异划分方法，通过分类类群和功能性状解构不同的响应矩阵来解释物种组成。解释矩阵包括三个空间尺度上的环境变量和从邻域矩阵主成分分析中提取的空间变量。采用线性模型验证了空间和环境成分之间可能存在的相关性。结果:不同功能类群对空间和环境成分的贡献差异较大。在分类类群上，翅目和毛翅目的纯环境因子更为重要，双翅目(非手翅目)和手翅目、鞘翅目、蜉蝣目、翼翅目和大翅目的空间因子更为重要。飞行能力强的敏感组表现出更大的环境特征，而飞行能力弱的容忍组表现出更大的空间特征。此外，解释群落变化的重要变量来自不同的空间尺度(局部、河岸和流域)，取决于所分析的分类或功能群。然而，在几个群体中发现了森林的普遍影响。结论:2 Santos, M.R.等。《巴西湖沼学报》，2020,vol. 32, e20。从这个意义上说，受空间结构环境压力强烈影响的社区也与站点之间的空间距离密切相关。为了弄清环境和空间变化对群落组成的相关影响，提出了划分群落变化解释比例的统计技术(Borcard et al.， 1992)，成为元群落研究的重要工具。此外，所使用的空间尺度将是检测与环境和空间因素相关的生态模式的重要因素(Leibold et al.， 2004;Heino et al.， 2017;Tonkin et al.， 2017)。这一前提主要适用于大陆水生环境，其中许多溪流构成网络(Frissell et al.， 1986;Finn et al.， 2011;Tonkin等人，2017b)，它们的行为就像被碎片化矩阵断开的岛屿(Bilton等人，2001;Alemu et al.， 2017;Tonkin et al.， 2017)。水生昆虫的成功定植和持久性
{"title":"Pollution tolerance, flight capacity and natural history explain metacommunity structure in high-altitude stream insects","authors":"M. R. Santos, V. Saito, P. A. Z. Pamplin, A. A. Pereira, A. Fonseca-Gessner","doi":"10.1590/s2179-975x1019","DOIUrl":"https://doi.org/10.1590/s2179-975x1019","url":null,"abstract":"Aim: To test how different taxonomic and functional groups of aquatic insects from high-altitude streams respond to environmental and spatial gradients at multiple scales in Southeast of Brazil. Methods: Specimens were collected in 26 high-altitude streams distributed over a gradient of previously defined environmental quality. The taxonomic identification was made at the genus level and the functional classification was based on traits of flight capacity and pollution tolerance compiled from specific literature. We obtained local in situ data (limnological, sediments, and organic matter), as well as calculated land use at the riparian and drainage basin scale. A variation partitioning approach was used to explain species composition based on different response matrices deconstructed by both taxonomic groups and functional traits. The explanatory matrices encompassed environmental variables at three spatial scales and spatial variables extracted from Principal Components of Neighbor Matrices analysis. A linear model was applied to verify the possible correlation between spatial and environmental components. Results: The contribution of the spatial and environmental components varied strongly between taxonomic and functional groups. For taxonomic groups, the pure environmental component was more important for Odonata and Trichoptera, while spatial variables were more important for Diptera (non-Chironomidae) and Chironomidae, Coleoptera, Ephemeroptera, Plecoptera and Megaloptera. The sensitive groups with good flight capacity showed a greater environmental signature while the tolerant groups with low flight capacity had a greater spatial signature. Moreover, the important variables for explaining community variation were from different spatial scale (local, riparian and watershed) depending either on the analyzed taxonomic or on functional groups. However, a general effect of forests was found in several groups. Conclusions: It 2 Santos, M.R. et al. Acta Limnologica Brasiliensia, 2020, vol. 32, e20 to relate to both spatial and environmental factors concomitantly. In this sense, communities strongly affected by spatially structured environmental pressures would be expected to be strongly related to the spatial distance among sites as well. To disentangle the correlated effects of environmental and spatial variation on community composition, statistical techniques to partition the explained proportion of community variation were proposed (Borcard et al., 1992), becoming important tools in metacommunity studies. Moreover, the spatial scale used will be an important element to detect ecological patterns, both related to environmental and spatial factors (Leibold et al., 2004; Heino et al., 2017; Tonkin et al., 2017a). This premise is relevant mainly in continental aquatic environments in which many streams constitute networks (Frissell et al., 1986; Finn et al., 2011; Tonkin et al., 2017b) that behave like islands disconnected by the fragmented matrix","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67824180","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}
U. L. Fernandes, Grasiela Casas, T. M. Lopes, Leandra Palheta, L. Rodrigues, Bárbara Dunck
Abstract: Aim We evaluated the predation interactions between Moenkhausia sanctaefilomenae and periphytic algae, in the presence or absence of an intermediate consumer (zooplankton). We tested the following hypotheses using a microcosms experiment: 1) fish consume zooplankton when available, therefore reducing algae consumption and increasing algal biomass; 2) fish consume the same algal species in the presence or absence of zooplankton; 3) species from the low-profile of the periphytic algal matrix are less consumed; 4) there is no difference in the nestedness of the networks between treatments, but the network in the treatment with zooplankton is modular; 5) the treatment with zooplankton shows higher interaction diversity, evenness and specialization degree. Methods The microcosms were separated in three treatments, control (no herbivores), T1 with periphytic algae and fish, and T2 with periphytic algae, fish and zooplankton. After seven days of experiment, the stomach contents were analyzed and quantified according to the algal profiles of the periphytic matrix. We also used the individual-resource network to investigate the differences in the individuals’ diet preferences between treatments. Results The fish diet did not differ between food webs with zooplankton presence or absence. They fed more on the algal medium profile, which also predominated in the control. The main food items were the diatoms Ulnaria ulna and Achnanthidium minutissimum. The interaction network results showed that the two treatments presented network modularity, and T2 (with zooplankton) presented nested network, in addition to showing greater interaction diversity and evenness, and less specialization of interactions. Conclusions Moenkhausia sanctaefilomenae can take advantage of a more abundant resource, and the presence or not of zooplankton did not alter the herbivory interaction. Considering the individual-resource network patterns, individuals of fish showed differences in how they share resources between treatments, with presence of opportunistic and selective individuals, and distinct distribution and diversity of interactions in the presence of zooplankton.
{"title":"Eating at the edges: the feeding mode and the individual-resource networks of a characid fish in the periphyton","authors":"U. L. Fernandes, Grasiela Casas, T. M. Lopes, Leandra Palheta, L. Rodrigues, Bárbara Dunck","doi":"10.1590/s2179-975x8720","DOIUrl":"https://doi.org/10.1590/s2179-975x8720","url":null,"abstract":"Abstract: Aim We evaluated the predation interactions between Moenkhausia sanctaefilomenae and periphytic algae, in the presence or absence of an intermediate consumer (zooplankton). We tested the following hypotheses using a microcosms experiment: 1) fish consume zooplankton when available, therefore reducing algae consumption and increasing algal biomass; 2) fish consume the same algal species in the presence or absence of zooplankton; 3) species from the low-profile of the periphytic algal matrix are less consumed; 4) there is no difference in the nestedness of the networks between treatments, but the network in the treatment with zooplankton is modular; 5) the treatment with zooplankton shows higher interaction diversity, evenness and specialization degree. Methods The microcosms were separated in three treatments, control (no herbivores), T1 with periphytic algae and fish, and T2 with periphytic algae, fish and zooplankton. After seven days of experiment, the stomach contents were analyzed and quantified according to the algal profiles of the periphytic matrix. We also used the individual-resource network to investigate the differences in the individuals’ diet preferences between treatments. Results The fish diet did not differ between food webs with zooplankton presence or absence. They fed more on the algal medium profile, which also predominated in the control. The main food items were the diatoms Ulnaria ulna and Achnanthidium minutissimum. The interaction network results showed that the two treatments presented network modularity, and T2 (with zooplankton) presented nested network, in addition to showing greater interaction diversity and evenness, and less specialization of interactions. Conclusions Moenkhausia sanctaefilomenae can take advantage of a more abundant resource, and the presence or not of zooplankton did not alter the herbivory interaction. Considering the individual-resource network patterns, individuals of fish showed differences in how they share resources between treatments, with presence of opportunistic and selective individuals, and distinct distribution and diversity of interactions in the presence of zooplankton.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67872245","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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