Pub Date : 2021-07-06DOI: 10.1080/11956860.2021.1934299
K. Salgado, M. L. Martínez, L. Álvarez-Molina, P. Hesp, M. Equihua, I. Mariño‐Tapia
ABSTRACT In Mexico, as in other countries, coastal urbanization and landscape changes are occurring at an unprecedented scale and rate, with potential negative impacts on local biodiversity. Nevertheless, studies of the impacts that such changes have on coastal dune vegetation are relatively scarce. In this study, we examined (a) the trends of urban sprawl and landscape changes along the coast of Veracruz for more than 20 years; (b) the impact of urban sprawl on plant species richness and plant functional groups; c) how landscape changes have affected plant diversity and community structure. Our results show an increasing urbanization along the coasts of the Gulf of Mexico, occurring at different rates, and being higher in locations closest to tourist areas. Plant species richness decreased with urban expansion while the proportion of plant functional types was altered. Inland species not tolerant to the beach-dune environment became more abundant in the most urbanized locations while the abundance of psammophytes decreased. Community structure (the dominant species) was modified with landscape changes. Our results are useful for an adaptive management strategy and will help develop sustainable beach management plans that should include the conservation of native and highly specialized species, such as psammophytes. RÉSUMÉ Au Mexique, comme dans d'autres pays, l'urbanisation côtière et les changements du paysage ont lieu à une échelle et à un rythme sans précédents, avec des effets négatifs potentiels sur la biodiversité locale. Néanmoins, les études des effets de ces changements sur la végétation des dunes côtières sont relativement rares. Dans la présente étude, nous avons examiné (a) les tendances d'étalement urbain et de modification du paysage le long de la côte de Veracruz pendant plus de 20 ans; (b) les effets de l'étalement urbain sur la richesse spécifique végétale et sur les groupes fonctionnels de plantes; (c) comment les changements du paysage ont affecté la diversité végétale et la structure des communautés. Nos résultats montrent une augmentation de l'urbanisation le long des côtes du Golfe du Mexique, dont le rythme est variable et plus élevé dans les lieux les plus près des sites touristiques. La richesse spécifique végétale diminue avec l'urbanisation, alors que la proportion de types fonctionnels est altérée. Les espèces continentales intolérantes aux environnements dunaires ou de plages deviennent plus abondantes dans les lieux plus urbanisés, alors que l'abondance des psammophytes diminue. La structure des communautés (les espèces dominantes) est modifiée par les changements du paysage. Nos résultats seront utiles à une stratégie d'aménagement adaptatif et aideront à développer des plans d'aménagement durable des plages qui devraient inclure la conservation d'espèces indigènes hautement spécialisées telles que les psammophytes.
{"title":"Impact of Urbanization and Landscape Changes on the Vegetation of Coastal Dunes along the Gulf of Mexico","authors":"K. Salgado, M. L. Martínez, L. Álvarez-Molina, P. Hesp, M. Equihua, I. Mariño‐Tapia","doi":"10.1080/11956860.2021.1934299","DOIUrl":"https://doi.org/10.1080/11956860.2021.1934299","url":null,"abstract":"ABSTRACT In Mexico, as in other countries, coastal urbanization and landscape changes are occurring at an unprecedented scale and rate, with potential negative impacts on local biodiversity. Nevertheless, studies of the impacts that such changes have on coastal dune vegetation are relatively scarce. In this study, we examined (a) the trends of urban sprawl and landscape changes along the coast of Veracruz for more than 20 years; (b) the impact of urban sprawl on plant species richness and plant functional groups; c) how landscape changes have affected plant diversity and community structure. Our results show an increasing urbanization along the coasts of the Gulf of Mexico, occurring at different rates, and being higher in locations closest to tourist areas. Plant species richness decreased with urban expansion while the proportion of plant functional types was altered. Inland species not tolerant to the beach-dune environment became more abundant in the most urbanized locations while the abundance of psammophytes decreased. Community structure (the dominant species) was modified with landscape changes. Our results are useful for an adaptive management strategy and will help develop sustainable beach management plans that should include the conservation of native and highly specialized species, such as psammophytes. RÉSUMÉ Au Mexique, comme dans d'autres pays, l'urbanisation côtière et les changements du paysage ont lieu à une échelle et à un rythme sans précédents, avec des effets négatifs potentiels sur la biodiversité locale. Néanmoins, les études des effets de ces changements sur la végétation des dunes côtières sont relativement rares. Dans la présente étude, nous avons examiné (a) les tendances d'étalement urbain et de modification du paysage le long de la côte de Veracruz pendant plus de 20 ans; (b) les effets de l'étalement urbain sur la richesse spécifique végétale et sur les groupes fonctionnels de plantes; (c) comment les changements du paysage ont affecté la diversité végétale et la structure des communautés. Nos résultats montrent une augmentation de l'urbanisation le long des côtes du Golfe du Mexique, dont le rythme est variable et plus élevé dans les lieux les plus près des sites touristiques. La richesse spécifique végétale diminue avec l'urbanisation, alors que la proportion de types fonctionnels est altérée. Les espèces continentales intolérantes aux environnements dunaires ou de plages deviennent plus abondantes dans les lieux plus urbanisés, alors que l'abondance des psammophytes diminue. La structure des communautés (les espèces dominantes) est modifiée par les changements du paysage. Nos résultats seront utiles à une stratégie d'aménagement adaptatif et aideront à développer des plans d'aménagement durable des plages qui devraient inclure la conservation d'espèces indigènes hautement spécialisées telles que les psammophytes.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1934299","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46174162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.1080/11956860.2021.1916215
E. J. Moran, N. Lecomte, P. Leighton, A. Hurford
ABSTRACT Arctic fox (Vulpes lagopus) and its tundra habitat are a unique system for the study of rabies virus epidemics. Contrary to theoretical calculations reporting a critical density (KT) of approximately 1 fox/km2 for rabies endemicity, arctic rabies persists at densities below this. The calculation of KT = 1 fox/km2 assumes uniform fox density across the landscape and unrestricted mixing between susceptible and infected foxes. We hypothesize that spatial heterogeneity arising from resource distribution or social structure may result in regions where rabies is endemic, even though average fox densities at the regional or landscape-level are below KT. To expand upon the limited body of research surrounding arctic rabies persistence, we examine arctic rabies via a two-patch structure. We find that arctic rabies can persist in heterogeneous landscapes where the mean carrying capacity is below the threshold carrying capacity required for endemicity in homogeneous landscapes. Rabies endemicity in low-carrying capacity regions within heterogeneous landscapes is further facilitated by high transmission rates, potentially due to non-breeding foxes (i.e. floaters), and when between-patch movement is restricted to latent and infected foxes. Our results suggest that rabies may persist in heterogeneous landscapes when the mean carrying capacity is as low as 0.25 foxes/km2.
{"title":"Understanding Rabies Persistence in Low-Density Fox Populations","authors":"E. J. Moran, N. Lecomte, P. Leighton, A. Hurford","doi":"10.1080/11956860.2021.1916215","DOIUrl":"https://doi.org/10.1080/11956860.2021.1916215","url":null,"abstract":"ABSTRACT Arctic fox (Vulpes lagopus) and its tundra habitat are a unique system for the study of rabies virus epidemics. Contrary to theoretical calculations reporting a critical density (KT) of approximately 1 fox/km2 for rabies endemicity, arctic rabies persists at densities below this. The calculation of KT = 1 fox/km2 assumes uniform fox density across the landscape and unrestricted mixing between susceptible and infected foxes. We hypothesize that spatial heterogeneity arising from resource distribution or social structure may result in regions where rabies is endemic, even though average fox densities at the regional or landscape-level are below KT. To expand upon the limited body of research surrounding arctic rabies persistence, we examine arctic rabies via a two-patch structure. We find that arctic rabies can persist in heterogeneous landscapes where the mean carrying capacity is below the threshold carrying capacity required for endemicity in homogeneous landscapes. Rabies endemicity in low-carrying capacity regions within heterogeneous landscapes is further facilitated by high transmission rates, potentially due to non-breeding foxes (i.e. floaters), and when between-patch movement is restricted to latent and infected foxes. Our results suggest that rabies may persist in heterogeneous landscapes when the mean carrying capacity is as low as 0.25 foxes/km2.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1916215","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42777623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-10DOI: 10.1080/11956860.2021.1932294
N. Roy, J. Woollett, N. Bhiry, Isabel Lemus-Lauzon, A. Delwaide, D. Marguerie
ABSTRACT Several recent dendrochronological, macrofossil and palynological studies have surveyed modern spruce forests at multiple locations in the Nain region of coastal Nunatsiavut (north-central Labrador) in order to reconstruct past forest composition, growth rates, species diversity and harvesting patterns. The present paper synthesizes original and previously collected data to evaluate the extent to which the dynamics of the region's spruce forests over the past five centuries have been related to anthropogenic impacts. In three key case studies, Picea growth release events demonstrate multiple isolated forest disturbances prior to the late 19th century. In general, these events correspond to the local human settlement history rather than to regional climatic trends, suggesting that ongoing human impacts on the forest extend as far back as the 17th century. Disturbance regimes accelerated by ca 1875 and afterward in all of the study sites. This increase in forest disturbance corresponds to increased demands for wood triggered by socioeconomic changes experienced by the region's Inuit and Settler communities. Ongoing surveys demonstrate the presence of markers of human exploitation of forests throughout the study region, and especially in coastal locations, suggesting that anthropogenic impacts are in fact generalised and not limited to specific areas of recent settlement.
{"title":"Anthropogenic and Climate Impacts on Subarctic Forests in the Nain Region, Nunatsiavut: Dendroecological and Historical Approaches","authors":"N. Roy, J. Woollett, N. Bhiry, Isabel Lemus-Lauzon, A. Delwaide, D. Marguerie","doi":"10.1080/11956860.2021.1932294","DOIUrl":"https://doi.org/10.1080/11956860.2021.1932294","url":null,"abstract":"ABSTRACT Several recent dendrochronological, macrofossil and palynological studies have surveyed modern spruce forests at multiple locations in the Nain region of coastal Nunatsiavut (north-central Labrador) in order to reconstruct past forest composition, growth rates, species diversity and harvesting patterns. The present paper synthesizes original and previously collected data to evaluate the extent to which the dynamics of the region's spruce forests over the past five centuries have been related to anthropogenic impacts. In three key case studies, Picea growth release events demonstrate multiple isolated forest disturbances prior to the late 19th century. In general, these events correspond to the local human settlement history rather than to regional climatic trends, suggesting that ongoing human impacts on the forest extend as far back as the 17th century. Disturbance regimes accelerated by ca 1875 and afterward in all of the study sites. This increase in forest disturbance corresponds to increased demands for wood triggered by socioeconomic changes experienced by the region's Inuit and Settler communities. Ongoing surveys demonstrate the presence of markers of human exploitation of forests throughout the study region, and especially in coastal locations, suggesting that anthropogenic impacts are in fact generalised and not limited to specific areas of recent settlement.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1932294","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48997706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-09DOI: 10.1080/11956860.2021.1916214
Z. Rahmad, Mohamad Syafiq Johari, P. Addo‐Fordjour
ABSTRACT Knowledge of the drivers of liana community structure is fundamental to understand the processes driving community assembly. We investigated variation in liana community structure (diversity, composition, abundance, basal area, distribution) among different elevations, and assessed the environmental factors structuring composition and distribution. We randomly established thirty 20 × 20 m plots across three elevations (lower = 200 m a.s.l.; middle = 500 m a.s.l.; upper = 850 m a. s.l.) in the Mount Jerai Forest Reserve, Malaysia. We used Canonical Correspondence Analysis to assess the relationships between liana species distribution and composition, and environmental factors. Liana diversity differed significantly among elevations, being highest and lowest in the middle and upper elevations, respectively. Liana abundance and basal area were higher at lower elevations. Species abundance varied significantly across elevations. The environmental factors showed significant variation among the elevations. Liana species composition and distribution patterns were explained by elevation, soil moisture, Ca, P, pH and N. The different environmental factors affected species composition and distribution in different ways. These findings increase our understanding of the drivers of liana community structure and may be useful in liana management and conservation.
了解藤本群落结构的驱动因素是理解群落组装过程的基础。我们调查了不同海拔地区藤本植物群落结构（多样性、组成、丰度、基底面积、分布）的变化，并评估了构成组成和分布的环境因素。我们在马来西亚杰莱山森林保护区的三个海拔高度（低=200 m a.s.l.；中=500 m a.s.l..；高=850 m a.s.l.）随机建立了30个20×20 m的地块。我们使用典型对应分析来评估藤本植物的物种分布和组成与环境因素之间的关系。不同海拔高度的藤本植物多样性差异显著，中海拔和高海拔分别最高和最低。低海拔地区藤本植物的丰富度和基底面积较高。不同海拔地区的物种丰度差异很大。不同海拔高度的环境因子差异显著。海拔、土壤水分、Ca、P、pH和N解释了莲属植物的组成和分布模式。不同的环境因素对莲属植物组成和分布有不同的影响。这些发现增加了我们对藤本植物群落结构驱动因素的理解，可能对藤本动物的管理和保护有用。
{"title":"Local Environmental Factors Shape Liana Community Structure along an Elevation Gradient in a Tropical Rainforest","authors":"Z. Rahmad, Mohamad Syafiq Johari, P. Addo‐Fordjour","doi":"10.1080/11956860.2021.1916214","DOIUrl":"https://doi.org/10.1080/11956860.2021.1916214","url":null,"abstract":"ABSTRACT Knowledge of the drivers of liana community structure is fundamental to understand the processes driving community assembly. We investigated variation in liana community structure (diversity, composition, abundance, basal area, distribution) among different elevations, and assessed the environmental factors structuring composition and distribution. We randomly established thirty 20 × 20 m plots across three elevations (lower = 200 m a.s.l.; middle = 500 m a.s.l.; upper = 850 m a. s.l.) in the Mount Jerai Forest Reserve, Malaysia. We used Canonical Correspondence Analysis to assess the relationships between liana species distribution and composition, and environmental factors. Liana diversity differed significantly among elevations, being highest and lowest in the middle and upper elevations, respectively. Liana abundance and basal area were higher at lower elevations. Species abundance varied significantly across elevations. The environmental factors showed significant variation among the elevations. Liana species composition and distribution patterns were explained by elevation, soil moisture, Ca, P, pH and N. The different environmental factors affected species composition and distribution in different ways. These findings increase our understanding of the drivers of liana community structure and may be useful in liana management and conservation.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1916214","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48817590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-08DOI: 10.1080/11956860.2021.1932293
I. MacGregor‐Fors, M. Gómez-Martínez, L. Vázquez, M. L. Martínez
ABSTRACT Caribbean islands are important hotspots for endemic species, concentrating high biodiversity on exceptionally small areas. Cozumel Island is not an exception, yet little published information exists on its bird diversity. In this study, we assessed the contribution of each major ecosystem of Cozumel Island (i.e., tropical forest, mangrove, palm thicket, and urban setting) to the island's avian diversity. Avian richness was highest in tropical forests, followed by mangroves, palm thickets, and urban setting. Bird densities were highest in urban settings, followed by tropical forests, mangroves, and palm thickets. Species composition similarity among ecosystems was low, with the most dissimilar ecosystem being the urban setting. Interestingly, we recorded the highest number of unique species in mangroves, followed by tropical forests, urban settings, and palm thickets. Tropical forests and mangroves of Cozumel Island are the main ecosystems harboring high avian diversity, with tropical forests housing high avian densities and endemics and mangroves including the most unique species. As expected, the contribution of urban settings to the avian diversity of Cozumel Island is limited and includes some highly abundant invasive species, of which the Eurasian Collared-Dove could represent a major ecological threat.
{"title":"Birds of the Land of Swallows: Contribution of the Main Ecosystems of Cozumel Island to Its Avian Diversity","authors":"I. MacGregor‐Fors, M. Gómez-Martínez, L. Vázquez, M. L. Martínez","doi":"10.1080/11956860.2021.1932293","DOIUrl":"https://doi.org/10.1080/11956860.2021.1932293","url":null,"abstract":"ABSTRACT Caribbean islands are important hotspots for endemic species, concentrating high biodiversity on exceptionally small areas. Cozumel Island is not an exception, yet little published information exists on its bird diversity. In this study, we assessed the contribution of each major ecosystem of Cozumel Island (i.e., tropical forest, mangrove, palm thicket, and urban setting) to the island's avian diversity. Avian richness was highest in tropical forests, followed by mangroves, palm thickets, and urban setting. Bird densities were highest in urban settings, followed by tropical forests, mangroves, and palm thickets. Species composition similarity among ecosystems was low, with the most dissimilar ecosystem being the urban setting. Interestingly, we recorded the highest number of unique species in mangroves, followed by tropical forests, urban settings, and palm thickets. Tropical forests and mangroves of Cozumel Island are the main ecosystems harboring high avian diversity, with tropical forests housing high avian densities and endemics and mangroves including the most unique species. As expected, the contribution of urban settings to the avian diversity of Cozumel Island is limited and includes some highly abundant invasive species, of which the Eurasian Collared-Dove could represent a major ecological threat.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1932293","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46918237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-07DOI: 10.1080/11956860.2021.1926137
C. Nozais, W. Vincent, C. Belzile, M. Gosselin, Marie-Amélie Blais, J. Canário, P. Archambault
ABSTRACT The Great Whale River in subarctic Quebec, Canada, is one of the main freshwater inflows to Hudson Bay. This region is experiencing rapid climate change, with pronounced impacts on the cryosphere, and ongoing socio-economic development that may accelerate with future road and shipping links. This review integrates information available to date on the Great Whale River ecosystem, which we define as the river and its watershed, its source lakes and streams, and the river mouth environment and beyond the shoreline in southeastern Hudson Bay. Our aim was to define the current state of this ecosystem as a baseline for ongoing observations, with emphasis on (1) the distribution of water masses, optical characteristics, freshwater discharge, and ice cover; (2) concentrations and fluxes of carbon, nutrients, and contaminants; (3) abundance, production and diversity of the organisms associated with the sea ice ecosystem; (4) plankton abundance, biomass, production, and assemblages; (5) benthic abundance and diversity; (6) fish abundance, diversity and population dynamics; (7) marine mammal biology; and (8) global change impacts on freshwater and marine habitats. This synthesis provides a first step towards the integrated management of the Great Whale River ecosystem, and for similar freshwater-marine systems in the subarctic region.
{"title":"The Great Whale River Ecosystem: Ecology of a Subarctic River and its Receiving Waters in Coastal Hudson Bay, Canada","authors":"C. Nozais, W. Vincent, C. Belzile, M. Gosselin, Marie-Amélie Blais, J. Canário, P. Archambault","doi":"10.1080/11956860.2021.1926137","DOIUrl":"https://doi.org/10.1080/11956860.2021.1926137","url":null,"abstract":"ABSTRACT The Great Whale River in subarctic Quebec, Canada, is one of the main freshwater inflows to Hudson Bay. This region is experiencing rapid climate change, with pronounced impacts on the cryosphere, and ongoing socio-economic development that may accelerate with future road and shipping links. This review integrates information available to date on the Great Whale River ecosystem, which we define as the river and its watershed, its source lakes and streams, and the river mouth environment and beyond the shoreline in southeastern Hudson Bay. Our aim was to define the current state of this ecosystem as a baseline for ongoing observations, with emphasis on (1) the distribution of water masses, optical characteristics, freshwater discharge, and ice cover; (2) concentrations and fluxes of carbon, nutrients, and contaminants; (3) abundance, production and diversity of the organisms associated with the sea ice ecosystem; (4) plankton abundance, biomass, production, and assemblages; (5) benthic abundance and diversity; (6) fish abundance, diversity and population dynamics; (7) marine mammal biology; and (8) global change impacts on freshwater and marine habitats. This synthesis provides a first step towards the integrated management of the Great Whale River ecosystem, and for similar freshwater-marine systems in the subarctic region.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1926137","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43930367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-03DOI: 10.1080/11956860.2021.1926642
Biljana Narancic, Émilie Saulnier‐Talbot, G. St‐Onge, R. Pienitz
ABSTRACT The Arctic has warmed significantly over the past decades. However, the evolution of Arctic climate during the Holocene remains to be clarified in more detail, and regional factors controlling aquatic ecosystem evolution need to be better defined to grasp the sensitivity of lakes to rapid environmental change. Nettilling Lake was studied for changes in sedimentary diatom assemblages over the last 5 000 years. Lake water pH was reconstructed by applying a diatom-based lake water pH inference model. We hypothesized that the changes in diatom assemblages were driven by variations in lake water transparency and attendant water turbidity associated with the input of fine suspended solids from glacial meltwaters. Reduced underwater light resulted in greater abundance of planktonic over benthic taxa from ca. 5 000 to 3 000 yrs. cal. BP, followed by less turbid conditions and proliferation of benthic taxa during regional cooling. The lake water was slightly alkaline throughout the Holocene, ranging between pH 7.1 and 7.7. Our results support the notion that hydrological processes, dependent on climate variations, have a first-order influence on the regulation of the lake water pH through glacial meltwater inputs, which will likely continue to control the lake's long-term chemical and biological evolution.
{"title":"Diatom Sedimentary Assemblages and Holocene pH Reconstruction from the Canadian Arctic Archipelago's Largest Lake","authors":"Biljana Narancic, Émilie Saulnier‐Talbot, G. St‐Onge, R. Pienitz","doi":"10.1080/11956860.2021.1926642","DOIUrl":"https://doi.org/10.1080/11956860.2021.1926642","url":null,"abstract":"ABSTRACT The Arctic has warmed significantly over the past decades. However, the evolution of Arctic climate during the Holocene remains to be clarified in more detail, and regional factors controlling aquatic ecosystem evolution need to be better defined to grasp the sensitivity of lakes to rapid environmental change. Nettilling Lake was studied for changes in sedimentary diatom assemblages over the last 5 000 years. Lake water pH was reconstructed by applying a diatom-based lake water pH inference model. We hypothesized that the changes in diatom assemblages were driven by variations in lake water transparency and attendant water turbidity associated with the input of fine suspended solids from glacial meltwaters. Reduced underwater light resulted in greater abundance of planktonic over benthic taxa from ca. 5 000 to 3 000 yrs. cal. BP, followed by less turbid conditions and proliferation of benthic taxa during regional cooling. The lake water was slightly alkaline throughout the Holocene, ranging between pH 7.1 and 7.7. Our results support the notion that hydrological processes, dependent on climate variations, have a first-order influence on the regulation of the lake water pH through glacial meltwater inputs, which will likely continue to control the lake's long-term chemical and biological evolution.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1926642","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46550102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.1080/11956860.2021.1921935
S. Covarrubias, C. Gutiérrez-Rodríguez, Octavio R. Rojas-Soto, R. Hernández-Guzmán, Clementina González
ABSTRACT The increase in anthropogenic activities that lead to fragmentation and habitat loss, could result in a reduction of connectivity among habitat patches of terrestrial species. We used ecological niche models, circuit and graph theories to evaluate functional connectivity among home-range patches and suitable habitat patches of the Mexican Leaf Frog (Agalychnis dacnicolor), in a heterogeneous landscape of tropical dry forest (TDF) in central-western Mexico. We found high connectivity among home-range patches within the Chamela-Cuixmala Biosphere Reserve (CCBR) and among those surrounding the CCBR. Similarly, suitable habitat patches along the Pacific slope (except those in the South) were well-connected. Conversely, we detected weak connectivity in the southern and eastern parts of the study area, which is in accordance with the poor habitat quality and fragmentation that characterize that zone. Suitable habitat patches with the largest areas of TDF were the most important in maintaining functional connectivity, but only one patch was within a natural protected area. Our results highlight the importance of conserving large and continuous patches of habitat in a very threatened landscape to maintain connectivity in A. dacnicolor and probably in other anurans.
{"title":"Functional Connectivity of an Endemic Tree Frog in a Highly Threatened Tropical Dry Forest in Mexico","authors":"S. Covarrubias, C. Gutiérrez-Rodríguez, Octavio R. Rojas-Soto, R. Hernández-Guzmán, Clementina González","doi":"10.1080/11956860.2021.1921935","DOIUrl":"https://doi.org/10.1080/11956860.2021.1921935","url":null,"abstract":"ABSTRACT The increase in anthropogenic activities that lead to fragmentation and habitat loss, could result in a reduction of connectivity among habitat patches of terrestrial species. We used ecological niche models, circuit and graph theories to evaluate functional connectivity among home-range patches and suitable habitat patches of the Mexican Leaf Frog (Agalychnis dacnicolor), in a heterogeneous landscape of tropical dry forest (TDF) in central-western Mexico. We found high connectivity among home-range patches within the Chamela-Cuixmala Biosphere Reserve (CCBR) and among those surrounding the CCBR. Similarly, suitable habitat patches along the Pacific slope (except those in the South) were well-connected. Conversely, we detected weak connectivity in the southern and eastern parts of the study area, which is in accordance with the poor habitat quality and fragmentation that characterize that zone. Suitable habitat patches with the largest areas of TDF were the most important in maintaining functional connectivity, but only one patch was within a natural protected area. Our results highlight the importance of conserving large and continuous patches of habitat in a very threatened landscape to maintain connectivity in A. dacnicolor and probably in other anurans.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1921935","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49376041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-03DOI: 10.1080/11956860.2021.1907974
Émilie Desjardins, Sandra Lai, S. Payette, F. Vézina, Andrew Tam, D. Berteaux
ABSTRACT The startling warming of the Arctic is driving important environmental changes, but vegetation responses have been spatially heterogeneous and difficult to predict. In this context, establishing new ecological baselines and initiating monitoring schemes are essential. We conducted systematic plot-based surveys in the polar desert surrounding Alert (Nunavut, Canada). We aimed at (1) identifying distinct plant communities, (2) characterizing community attributes, including diversity and abundance, as well as environmental variables associated with each community, and (3) establishing a georeferenced baseline with permanent field markers allowing robust resurveying. We used hierarchical clustering to categorize cover values of vascular plant species, cryptogams, and ground substrates from 1,320 quadrats (1 m2 each) surveyed in 264 vegetation plots. Five plant communities were identified, with one community associated with each of the barren and mesic habitats, and three communities associated with wetlands. The mean biotic covers were generally higher at Alert (13–98%) compared to other polar deserts in the Canadian Arctic Archipelago. A total of 250 quadrats from 50 vegetation plots were permanently marked, and a database describing all plots is available online. This study improves our understanding of High-Arctic plant communities and establishes an important vegetation monitoring reference at the northernmost permanently inhabited settlement on Earth.
{"title":"Vascular Plant Communities in the Polar Desert of Alert (Ellesmere Island, Canada): Establishment of a Baseline Reference for the 21st Century","authors":"Émilie Desjardins, Sandra Lai, S. Payette, F. Vézina, Andrew Tam, D. Berteaux","doi":"10.1080/11956860.2021.1907974","DOIUrl":"https://doi.org/10.1080/11956860.2021.1907974","url":null,"abstract":"ABSTRACT The startling warming of the Arctic is driving important environmental changes, but vegetation responses have been spatially heterogeneous and difficult to predict. In this context, establishing new ecological baselines and initiating monitoring schemes are essential. We conducted systematic plot-based surveys in the polar desert surrounding Alert (Nunavut, Canada). We aimed at (1) identifying distinct plant communities, (2) characterizing community attributes, including diversity and abundance, as well as environmental variables associated with each community, and (3) establishing a georeferenced baseline with permanent field markers allowing robust resurveying. We used hierarchical clustering to categorize cover values of vascular plant species, cryptogams, and ground substrates from 1,320 quadrats (1 m2 each) surveyed in 264 vegetation plots. Five plant communities were identified, with one community associated with each of the barren and mesic habitats, and three communities associated with wetlands. The mean biotic covers were generally higher at Alert (13–98%) compared to other polar deserts in the Canadian Arctic Archipelago. A total of 250 quadrats from 50 vegetation plots were permanently marked, and a database describing all plots is available online. This study improves our understanding of High-Arctic plant communities and establishes an important vegetation monitoring reference at the northernmost permanently inhabited settlement on Earth.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1907974","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42254320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.1080/11956860.2021.1917859
Evelyne Lemay, S. Côté, J. Tremblay
ABSTRACT Increased snow cover and attenuation of light due to shrub expansion can lead to changes in the quantity and nutritional quality of food resources for migratory caribou (Rangifer tarandus). To determine how vegetation is affected by snow accumulation and shade, we conducted an experiment that simulated the light and snow conditions created by increased shrub cover at Deception Bay (Nunavik, Canada), within the summer range of the Rivière-aux-Feuilles caribou herd. We estimated the foliar biomass of two major components of the caribou diet (Betula glandulosa and Carex spp.). We also harvested foliar tissue to conduct chemical composition analyses (nitrogen, fibre, total phenolics). Experimental light attenuation was found to increase the nitrogen concentrations in B. glandulosa and Carex spp. throughout the growing season. Phenolic concentration in B. glandulosa decreased in early summer but was otherwise consistent in response to light attenuation and increased snow cover. Increased snow cover combined with ambient light had a positive effect on the foliar biomass of B. glandulosa. Increased snow cover and shade caused by shrub densification may therefore increase forage quantity and quality for caribou. We suggest investigating the effects of shrub expansion on other components of the caribou diet, such as lichens and forbs.
{"title":"How will Snow Retention and Shading from Arctic Shrub Expansion Affect Caribou Food Resources?","authors":"Evelyne Lemay, S. Côté, J. Tremblay","doi":"10.1080/11956860.2021.1917859","DOIUrl":"https://doi.org/10.1080/11956860.2021.1917859","url":null,"abstract":"ABSTRACT Increased snow cover and attenuation of light due to shrub expansion can lead to changes in the quantity and nutritional quality of food resources for migratory caribou (Rangifer tarandus). To determine how vegetation is affected by snow accumulation and shade, we conducted an experiment that simulated the light and snow conditions created by increased shrub cover at Deception Bay (Nunavik, Canada), within the summer range of the Rivière-aux-Feuilles caribou herd. We estimated the foliar biomass of two major components of the caribou diet (Betula glandulosa and Carex spp.). We also harvested foliar tissue to conduct chemical composition analyses (nitrogen, fibre, total phenolics). Experimental light attenuation was found to increase the nitrogen concentrations in B. glandulosa and Carex spp. throughout the growing season. Phenolic concentration in B. glandulosa decreased in early summer but was otherwise consistent in response to light attenuation and increased snow cover. Increased snow cover combined with ambient light had a positive effect on the foliar biomass of B. glandulosa. Increased snow cover and shade caused by shrub densification may therefore increase forage quantity and quality for caribou. We suggest investigating the effects of shrub expansion on other components of the caribou diet, such as lichens and forbs.","PeriodicalId":51030,"journal":{"name":"Ecoscience","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/11956860.2021.1917859","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44618568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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