The Sumampa River in Mampong-Ashanti in Ghana is a very important river that supplies water to the water processing company for treatment for the whole community and its environs. In spite of its importance, the buffe...The Sumampa River in Mampong-Ashanti in Ghana is a very important river that supplies water to the water processing company for treatment for the whole community and its environs. In spite of its importance, the buffer area of the river has been encroached by settlers. Residential houses sited along the river have channeled their waste water into the river and several anthropogenic activities go on along the river. Therefore, this study was conducted to assess the effects of anthropogenic activities on the quality of the river. Water samples were collected from various parts of the river including the source and outflow for physico-chemical and microbial analyses. The results showed that, the water was highly turbid with high total dissolved solids at some points because of intense anthropogenic activities. High turbidity and total dissolved solids greatly influence the microbial load of the water. We therefore recommend that measures are put in place to protect the Sumampa River through the creation of a buffer zone by planting trees along the banks of the river. The trees could help detoxify the run-off water that flows into the river.展开更多
It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk...It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk of intraguild predation exists. Here, we show how the smaller carnivore Egyptian mongoose (Herpestes ichneumon) may coexist on a local scale with its intraguild pre- dator, the Iberian lynx (Lynx pardinus), by using places with different microhabitat character- istics. We expect that mongooses living within lynx home ranges will use denser and more protective habitats when active in order to di- minish their risk of being killed by lynx com- pared to those living in areas similar in vege- tation and prey availability but where lynx are absent. The scrubland cover of points used by mongooses outside lynx areas, and that of points located within lynx areas but not used by mongooses, were significantly lower than, or similar to, cover of points used by mongooses within lynx areas. The probability of finding mon- goose tracks was constant across levels of scrubland cover when lynx were absent, but more mongoose tracks were likely to be found in thicker scrubland within lynx areas, especially if these areas were intensively used by lynx. This result agrees with the hypothesis on shifts in microhabitat use of subordinate carnivores to prevent fatal or risky encounters with dominant ones.展开更多
Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity.The...Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity.The dice snake Natrix tessellata,widely distributed in the Western Palearctic is one such species.We aimed to resolve a detailed phylogeography of N.tessellata with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages,trace their origin,and correlate the environmental changes that affected their distribution through time.The expected time of divergence of both clades began at 3.7 Mya in the Pliocene,reaching lineage differentiation approximately 1 million years later.The genetic diversity in both clades is rich,suggesting different ancestral areas,glacial refugia,demographic changes,and colonization routes.The Caspian lineage is the most widespread lineage in Central Asia,distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan,and Eastern European lowlands in the west.Its distribution is limited by deserts,moun-tains,and cold steppe environments.Similarly,Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia,with ranges delimited by the large Kyzylkum and Karakum deserts.On the western side,there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western Asia.The distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes,mostly through aridification.展开更多
Certain traits of recipient environments,such as the availability of limiting resources,strongly determine the establishment success and spread of non-native species.These limitations may be overcome through behaviora...Certain traits of recipient environments,such as the availability of limiting resources,strongly determine the establishment success and spread of non-native species.These limitations may be overcome through behavioral plasticity,allowing them to exploit alternative resources.Here,we show how a secondary cavity nester bird,the rose-ringed parakeet Psittacula krameri,innovates its nesting behavior as a response to the shortage of tree cavities for nesting in its invasive range in Tenerife(Canary Islands).We observed that some breeding pairs excavated their own nest cavities in palms,thus becoming primary cavity nester,whereas others occupied nests built with wood sticks by another invasive species,the monk parakeet Myiopsitta monachus.The use of these novel nesting strategies increased the number of breeding pairs by up to 52%over 6 years,contributing to a 128.8%increase of the whole population.Innovative nests were located at greater heights above ground and were more aggregated around conspecifics but did not result in greater breeding success than natural cavities.Occupation of monk parakeet colonies by rose-ringed parakeets also benefited the former species through a protective-nesting association against nest predators.Our results show how an invasive species innovate nesting behaviors and increase nest-site availability in the recipient environment,thus facilitating its population growth and invasion process.Potential behavioral innovations in other invasive rose-ringed parakeet populations may be overlooked,and should be considered for effective management plans.展开更多
Shea(Vitellaria paradoxa C.F.Gaertn.)is a multipurpose tree species indigenous to the Sudano Sahelian zone of Africa and occurs as the most abundant economic tree species in northern Ghana.The edible oil(shea butter)e...Shea(Vitellaria paradoxa C.F.Gaertn.)is a multipurpose tree species indigenous to the Sudano Sahelian zone of Africa and occurs as the most abundant economic tree species in northern Ghana.The edible oil(shea butter)extracted from shea kernel is ranked as the most economic product of the species.Although fruit set and yield of shea are known to be influenced by insect pollination,the actual contribution of insect pollinators to its reproductive success has rarely been studied.This study estimated the percentage insect pollinator dependence and monetary value of insect pollination per bag of shea kernel(85 kg)in the Guinea savanna zone.Open pollination and insect exclusion treatments were applied to the flowers of 18 randomly selected matured shea trees and observed from the onset of flowering to fruit maturity.Proportion of total production value attributed to insect pollination approach was used in estimating the monetary value of pollination per bag of shea kernel with the average market price as proxy.The study revealed an insect pollinator dependence of 77%and 73%for fruit set and dry kernel yield,respectively.Mean number of fruit set per inflorescence varied significantly between insectexcluded and open-pollinated inflorescences(p<0.05).The monetary value of insect pollination was estimated at GH₵73.21(US$18.67)per bag of kernel as of August 2016.Shea is a high insect pollinator–dependent species and the conservation of insect pollinators would be critical to the sustainability of yield.展开更多
Background:Changes of land cover modify the characteristics of habitat,host-vector interaction and consequently infection rates of disease causing agents.In this paper,we report variations in tsetse distribution patte...Background:Changes of land cover modify the characteristics of habitat,host-vector interaction and consequently infection rates of disease causing agents.In this paper,we report variations in tsetse distribution patterns,abundance and infection rates in relation to habitat types and age in the Maasai Steppe of northern Tanzania.In Africa,Tsetse-transmitted trypanosomiasis negatively impacted human life where about 40 million people are at risk of contracting the disease with dramatic socio-economical consequences,for instance,loss of livestock,animal productivity,and manpower.Methods:We trapped tsetse flies in dry and wet seasons between October 2014 and May 2015 in selected habitats across four villages:Emboreet,Loiborsireet,Kimotorok and Oltukai adjacent to protected areas.Data collected include number and species of tsetse flies caught in baited traps,PCR identification of trypanosome species and extraction of monitored Normalized Difference Vegetation Index(NDVI)data from Moderate Resolution Imaging Spectrometer(MODIS).Results:Our findings demonstrate the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance.Results have shown higher tsetse fly abundance in Acacia-swampy ecotone and riverine habitats for Emboreet and other villages,respectively.Tsetse abundance was inconsistent among habitats in different villages.Emboreet was highly infested with Glossina swynnertoni(68%)in ecotone and swampy habitats followed by G.morsitans(28%)and G.pallidipes(4%)in riverine habitat.In the remaining villages,the dominant tsetse fly species by 95%was G.pallidipes in all habitats.Trypanosoma vivax was the most prevalent species in all infected flies(95%)with few observations of co-infections(with T.congolense or T.brucei).Conclusions:The findings of this study provide a framework to mapping hotspots of tsetse infestation and trypanosomiasis infection and enhance the communities to plan for effective control of trypanosomiasis.展开更多
Correction to:Ecol Process https://doi.org/10.1186/s13717-019-0202-8 In the original publication of this article(Nasare et al.2019),the‘₵’in Ghanaian currency symbol(GH₵)was omitted in below content in the pdf versi...Correction to:Ecol Process https://doi.org/10.1186/s13717-019-0202-8 In the original publication of this article(Nasare et al.2019),the‘₵’in Ghanaian currency symbol(GH₵)was omitted in below content in the pdf version of the article.It should be‘GH₵'1.“The monetary value of insect pollination was estimated at GH 73.21(US$18.67)per bag of kernel as of August 2016”.展开更多
Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic ...Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive responses.For this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish species.Enzyme activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species specific.The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish.Bioaccumulation factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna sp.Bioconcentration factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish species.An integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate.In general,the multiple indices exhibited variations and A.testudineus was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of ALT.The order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for A.testudineus,LPO>AChE>AST>Protease>CAT>Amylase>Lipase>GST>ALP>ALT for H.fossilis and AChE>CAT>LPO>AST>Amylase>GST>Protease>ALP>Lipase>ALT for O.niloticus.Finally,IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.展开更多
文摘The Sumampa River in Mampong-Ashanti in Ghana is a very important river that supplies water to the water processing company for treatment for the whole community and its environs. In spite of its importance, the buffer area of the river has been encroached by settlers. Residential houses sited along the river have channeled their waste water into the river and several anthropogenic activities go on along the river. Therefore, this study was conducted to assess the effects of anthropogenic activities on the quality of the river. Water samples were collected from various parts of the river including the source and outflow for physico-chemical and microbial analyses. The results showed that, the water was highly turbid with high total dissolved solids at some points because of intense anthropogenic activities. High turbidity and total dissolved solids greatly influence the microbial load of the water. We therefore recommend that measures are put in place to protect the Sumampa River through the creation of a buffer zone by planting trees along the banks of the river. The trees could help detoxify the run-off water that flows into the river.
基金funded by project CGL2004-00346/BOS of Ministry of Education and Sciencesupported by a predoctoral grant of CSIC-Spanish Council for Research,“I3P”programsupported by a FPU and a post-doctoral fellowships from the Spanish Ministry of Education.
文摘It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk of intraguild predation exists. Here, we show how the smaller carnivore Egyptian mongoose (Herpestes ichneumon) may coexist on a local scale with its intraguild pre- dator, the Iberian lynx (Lynx pardinus), by using places with different microhabitat character- istics. We expect that mongooses living within lynx home ranges will use denser and more protective habitats when active in order to di- minish their risk of being killed by lynx com- pared to those living in areas similar in vege- tation and prey availability but where lynx are absent. The scrubland cover of points used by mongooses outside lynx areas, and that of points located within lynx areas but not used by mongooses, were significantly lower than, or similar to, cover of points used by mongooses within lynx areas. The probability of finding mon- goose tracks was constant across levels of scrubland cover when lynx were absent, but more mongoose tracks were likely to be found in thicker scrubland within lynx areas, especially if these areas were intensively used by lynx. This result agrees with the hypothesis on shifts in microhabitat use of subordinate carnivores to prevent fatal or risky encounters with dominant ones.
基金supported by the Slovak Research and Development Agency under the contract APVV-19-0076 and by the grant VEGA 1/0242/21 of the Scientific Grant Agency of the Slovak RepublicSH was supported by the German Research Foundation(DFG,grant no.HO 3792/8-1)The work of OK was carried out within the framework of research topics of the state assignments nos.121032300023-7 and 122031100282-2.The research of DJ in Afghanistan has been approved by the National Environmental Protection Agency of the Islamic Emirate of Afghanistan(permits for access to genetic resources nos.12429 and 12455).
文摘Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity.The dice snake Natrix tessellata,widely distributed in the Western Palearctic is one such species.We aimed to resolve a detailed phylogeography of N.tessellata with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages,trace their origin,and correlate the environmental changes that affected their distribution through time.The expected time of divergence of both clades began at 3.7 Mya in the Pliocene,reaching lineage differentiation approximately 1 million years later.The genetic diversity in both clades is rich,suggesting different ancestral areas,glacial refugia,demographic changes,and colonization routes.The Caspian lineage is the most widespread lineage in Central Asia,distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan,and Eastern European lowlands in the west.Its distribution is limited by deserts,moun-tains,and cold steppe environments.Similarly,Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia,with ranges delimited by the large Kyzylkum and Karakum deserts.On the western side,there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western Asia.The distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes,mostly through aridification.
基金This work was supported by the Severo Ochoa Program(Grant No.SVP2014-068732)Action COST“ParrotNet”(Grant No.ES1304).
文摘Certain traits of recipient environments,such as the availability of limiting resources,strongly determine the establishment success and spread of non-native species.These limitations may be overcome through behavioral plasticity,allowing them to exploit alternative resources.Here,we show how a secondary cavity nester bird,the rose-ringed parakeet Psittacula krameri,innovates its nesting behavior as a response to the shortage of tree cavities for nesting in its invasive range in Tenerife(Canary Islands).We observed that some breeding pairs excavated their own nest cavities in palms,thus becoming primary cavity nester,whereas others occupied nests built with wood sticks by another invasive species,the monk parakeet Myiopsitta monachus.The use of these novel nesting strategies increased the number of breeding pairs by up to 52%over 6 years,contributing to a 128.8%increase of the whole population.Innovative nests were located at greater heights above ground and were more aggregated around conspecifics but did not result in greater breeding success than natural cavities.Occupation of monk parakeet colonies by rose-ringed parakeets also benefited the former species through a protective-nesting association against nest predators.Our results show how an invasive species innovate nesting behaviors and increase nest-site availability in the recipient environment,thus facilitating its population growth and invasion process.Potential behavioral innovations in other invasive rose-ringed parakeet populations may be overlooked,and should be considered for effective management plans.
文摘Shea(Vitellaria paradoxa C.F.Gaertn.)is a multipurpose tree species indigenous to the Sudano Sahelian zone of Africa and occurs as the most abundant economic tree species in northern Ghana.The edible oil(shea butter)extracted from shea kernel is ranked as the most economic product of the species.Although fruit set and yield of shea are known to be influenced by insect pollination,the actual contribution of insect pollinators to its reproductive success has rarely been studied.This study estimated the percentage insect pollinator dependence and monetary value of insect pollination per bag of shea kernel(85 kg)in the Guinea savanna zone.Open pollination and insect exclusion treatments were applied to the flowers of 18 randomly selected matured shea trees and observed from the onset of flowering to fruit maturity.Proportion of total production value attributed to insect pollination approach was used in estimating the monetary value of pollination per bag of shea kernel with the average market price as proxy.The study revealed an insect pollinator dependence of 77%and 73%for fruit set and dry kernel yield,respectively.Mean number of fruit set per inflorescence varied significantly between insectexcluded and open-pollinated inflorescences(p<0.05).The monetary value of insect pollination was estimated at GH₵73.21(US$18.67)per bag of kernel as of August 2016.Shea is a high insect pollinator–dependent species and the conservation of insect pollinators would be critical to the sustainability of yield.
基金This research received financial support from the project“Predicting vulnerability and improving resilience of the Maasai communities to vector borne infections:An Eco-health approach in Maasai steppe ecosystem,based at Nelson Mandela African Institute of Science and Technology(NM-AIST)”.
文摘Background:Changes of land cover modify the characteristics of habitat,host-vector interaction and consequently infection rates of disease causing agents.In this paper,we report variations in tsetse distribution patterns,abundance and infection rates in relation to habitat types and age in the Maasai Steppe of northern Tanzania.In Africa,Tsetse-transmitted trypanosomiasis negatively impacted human life where about 40 million people are at risk of contracting the disease with dramatic socio-economical consequences,for instance,loss of livestock,animal productivity,and manpower.Methods:We trapped tsetse flies in dry and wet seasons between October 2014 and May 2015 in selected habitats across four villages:Emboreet,Loiborsireet,Kimotorok and Oltukai adjacent to protected areas.Data collected include number and species of tsetse flies caught in baited traps,PCR identification of trypanosome species and extraction of monitored Normalized Difference Vegetation Index(NDVI)data from Moderate Resolution Imaging Spectrometer(MODIS).Results:Our findings demonstrate the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance.Results have shown higher tsetse fly abundance in Acacia-swampy ecotone and riverine habitats for Emboreet and other villages,respectively.Tsetse abundance was inconsistent among habitats in different villages.Emboreet was highly infested with Glossina swynnertoni(68%)in ecotone and swampy habitats followed by G.morsitans(28%)and G.pallidipes(4%)in riverine habitat.In the remaining villages,the dominant tsetse fly species by 95%was G.pallidipes in all habitats.Trypanosoma vivax was the most prevalent species in all infected flies(95%)with few observations of co-infections(with T.congolense or T.brucei).Conclusions:The findings of this study provide a framework to mapping hotspots of tsetse infestation and trypanosomiasis infection and enhance the communities to plan for effective control of trypanosomiasis.
文摘Correction to:Ecol Process https://doi.org/10.1186/s13717-019-0202-8 In the original publication of this article(Nasare et al.2019),the‘₵’in Ghanaian currency symbol(GH₵)was omitted in below content in the pdf version of the article.It should be‘GH₵'1.“The monetary value of insect pollination was estimated at GH 73.21(US$18.67)per bag of kernel as of August 2016”.
基金The authors like to thank the Head,Department of Environmental Science,The University of Burdwan,Burdwan,West Bengal,India for providing the laboratory facilities and library facilities during the course of research.We also like to thank the INSPIRE Program Division,Department of Science&Technology,Govt.of India(DST/INSPIRE Fellowship/2011/164,Dt.29.09.2011)for the financial assistance.We are also thankful to the respective reviewers for improving our manuscript.
文摘Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive responses.For this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish species.Enzyme activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species specific.The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish.Bioaccumulation factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna sp.Bioconcentration factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish species.An integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate.In general,the multiple indices exhibited variations and A.testudineus was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of ALT.The order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for A.testudineus,LPO>AChE>AST>Protease>CAT>Amylase>Lipase>GST>ALP>ALT for H.fossilis and AChE>CAT>LPO>AST>Amylase>GST>Protease>ALP>Lipase>ALT for O.niloticus.Finally,IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.
