scholarly journals Spatial and Temporal Distribution of Bacterioplankton Molecular Ecological Networks in the Yuan River under Different Human Activity Intensity

2021 ◽  
Vol 9 (7) ◽  
pp. 1532
Author(s):  
Bobo Wu ◽  
Peng Wang ◽  
Adam T. Devlin ◽  
Lu Chen ◽  
Yang Xia ◽  
...  
Keyword(s):  
Human Activity ◽  
Crucial Role ◽  
Keystone Species ◽  
Ecological Networks ◽  
Ecological Network ◽  
Activity Intensity ◽  
Dry Seasons ◽  
Intensity Stress ◽  
Molecular Ecological Network ◽  
Wet And Dry Seasons

Bacterioplankton communities play a crucial role in freshwater ecosystem functioning, but it is unknown how co-occurrence networks within these communities respond to human activity disturbances. This represents an important knowledge gap because changes in microbial networks could have implications for their functionality and vulnerability to future disturbances. Here, we compare the spatiotemporal and biogeographical patterns of bacterioplankton molecular ecological networks using high-throughput sequencing of Illumina HiSeq and multivariate statistical analyses from a subtropical river during wet and dry seasons. Results demonstrated that the lower reaches (high human activity intensity) network had less of an average degree (10.568/18.363), especially during the dry season, when compared with the upper reaches (low human activity intensity) network (10.685/37.552) during the wet and dry seasons, respectively. The latter formed more complexity networks with more modularity (0.622/0.556) than the lower reaches (high human activity intensity) network (0.505/0.41) during the wet and dry seasons, respectively. Bacterioplankton molecular ecological network under high human activity intensity became significantly less robust, which is mainly caused by altering of the environmental conditions and keystone species. Human activity altered the composition of modules but preserved their ecological roles in the network and environmental factors (dissolved organic carbon, temperature, arsenic, oxidation–reduction potential and Chao1 index) were the best parameters for explaining the variations in bacterioplankton molecular ecological network structure and modules. Proteobacteria, Actinobacteria and Bacteroidetes were the keystone phylum in shaping the structure and niche differentiations in the network. In addition, the lower reaches (high human activity intensity) reduce the bacterioplankton diversity and ecological niche differentiation, which deterministic processes become more important with increased farmland and constructed land area (especially farmland) with only 35% and 40% of the community variation explained by the neutral community model during the wet season and dry season, respectively. Keystone species in high human activity intensity stress habitats yield intense functional potentials and Bacterioplankton communities harbor keystone taxa in different human activity intensity stress habitats, which may exert their influence on microbiome network composition regardless of abundance. Therefore, human activity plays a crucial role in shaping the structure and function of bacterioplankton molecular ecological networks in subtropical rivers and understanding the mechanisms of this process can provide important information about human–water interaction processes, sustainable uses of freshwater as well as watershed management and conservation.

Declining human activity intensity on alpine grasslands of the Tibetan Plateau

2021 ◽  
Vol 296 ◽  
pp. 113198
Author(s):  
Meng Li ◽  
Xianzhou Zhang ◽  
Jianshuang Wu ◽  
Qiannan Ding ◽  
Ben Niu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Human Activity ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Activity Intensity

scholarly journals Seasonal and Temperature Dependent Variations in Proximate Parameters and Mineral Elements of Smoke-Dried Catfish (Clarias gariepinus, Burchell, 1822) using Traditional and Eco-Friendly Kilns in Lagos, Nigeria

2020 ◽  
Vol 24 (4) ◽  
pp. 639-643
Author(s):  
M.M. Ogunbambo
Keyword(s):  
Crude Protein ◽  
Clarias Gariepinus ◽  
Mineral Elements ◽  
Drying Process ◽  
Temperature Dependent ◽  
Crude Fibre ◽  
Significant Difference ◽  
Dry Seasons ◽  
Mineral Compositions ◽  
Wet And Dry Seasons

Smoke-drying Clarias gariepinus (catfish) provides animal protein and a source of livelihood in Lagos, Nigeria. Changes occurring to seasonal and mineral compositions of smoke-dried catfish using local Traditional Drum Kiln (TDK) and a newly constructed Eco-Friendly Kiln (EFK) fitted with a flame, drying and electronic components was carried out in this study. The smoke-drying process was carried out in both wet and dry seasons and smoke-dried catfish samples stored at ambient and adjusted refrigerated temperatures of 28 and 4 0C. The smoke-drying procedure was  standardized at 60 - 80 0C and kiln lasted 24 ± 3 hours. Moisture content results showed a significant difference when the catfish samples were smoke-dried using TDK and EFK and stored in ambient and controlled temperatures in both wet and dry seasons while crude protein, lipid, ash and crude fibre values were significantly different when stored only in dry season. Mineral elements phosphorus, sodium, copper, magnesium and iron showed a significant difference when stored at both temperatures and seasons using both kilns. Mineral elements were found to be most stable in smoke-dried catfish samples when stored at controlled temperatures. This work proved that standardizing smoke-drying process using both kilns resulted in good quality smoke-dried catfish but showed that higher biochemical values were obtained when EFK is used. Key words: Nigeria, Smoke-drying Kilns, Seasons, Ambient, Controlled Temperatures

scholarly journals Rice milling quality as affected by drying method and harvesting time during ripening in wet and dry seasons

2018 ◽  
Vol 22 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Phetmanyseng Xangsayasane ◽  
Khamtai Vongxayya ◽  
Senthong Phongchanmisai ◽  
Jaquie Mitchell ◽  
Shu Fukai
Keyword(s):  
Drying Method ◽  
Milling Quality ◽  
Harvesting Time ◽  
Dry Seasons ◽  
Rice Milling ◽  
Wet And Dry Seasons

scholarly journals Urbanization effects on the composition and structure of macrophytes communities in a lotic ecosystem of Pernambuco State, Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 888-897 ◽  
Author(s):  
L. R. C. C. Xavier ◽  
F. Scherner ◽  
D. C. Burgos ◽  
R. C. Barreto ◽  
S. M. B. Pereira
Keyword(s):  
Urban Areas ◽  
Floristic Composition ◽  
Freshwater Ecosystems ◽  
Metropolitan Region ◽  
Macrophyte Communities ◽  
Composition And Structure ◽  
Lotic Ecosystem ◽  
Dry Seasons ◽  
Urbanized Areas ◽  
Wet And Dry Seasons

Abstract Population growth in urban areas changes freshwater ecosystems, and this can have consequences for macrophyte communities as can be seen in the municipalities that border the Capibaribe River, Pernambuco, Brazil. This study reports the effects of urbanization on the composition and structure of macrophyte communities in areas along that river. The following urbanized and non-urbanized sampling sites were chosen: Sites 1 and 2 (municipality of Santa Cruz do Capibaribe), Sites 3 and 4 (municipality of Toritama), and Sites 5 and 6 (metropolitan region of Recife). These sites were visited every two months from January to July 2013 to observe seasonal variation (wet and dry seasons). Thirty-one species were identified. Generally, the non-urbanized sites had a higher number of species. Multivariate analyses indicated significant overall differences between urbanized and non-urbanized areas (R = 0.044; p < 0.001) and between seasons (R = 0.018; p < 0.019). Owing to the large variation in physical, chemical, and biological characteristics between urbanized and non-urbanized areas, we found that urbanization significantly influenced the floristic composition and structure of macrophyte communities.

scholarly journals Fruiting phenology and consumption by birds in Ficus calyptroceras (Miq.) Miq. (Moraceae)

2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Dry Season ◽  
Dry Forest ◽  
Wet Season ◽  
Frugivorous Birds ◽  
Fruiting Phenology ◽  
Dry Seasons ◽  
Seed Dispersers ◽  
Wet And Dry Seasons

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.

scholarly journals Development and comparative evaluation of a stochastic analog method to downscale daily GCM precipitation

2013 ◽  
Vol 17 (11) ◽  
pp. 4481-4502 ◽  
Author(s):  
S. Hwang ◽  
W. D. Graham
Keyword(s):  
Bias Correction ◽  
Daily Precipitation ◽  
Transition Probabilities ◽  
Small Scale ◽  
Analog Method ◽  
Dry Spell ◽  
Spatial Disaggregation ◽  
Dry Seasons ◽  
Stochastic Analog ◽  
Wet And Dry Seasons

Abstract. There are a number of statistical techniques that downscale coarse climate information from general circulation models (GCMs). However, many of them do not reproduce the small-scale spatial variability of precipitation exhibited by the observed meteorological data, which is an important factor for predicting hydrologic response to climatic forcing. In this study a new downscaling technique (Bias-Correction and Stochastic Analog method; BCSA) was developed to produce stochastic realizations of bias-corrected daily GCM precipitation fields that preserve both the spatial autocorrelation structure of observed daily precipitation sequences and the observed temporal frequency distribution of daily rainfall over space. We used the BCSA method to downscale 4 different daily GCM precipitation predictions from 1961 to 1999 over the state of Florida, and compared the skill of the method to results obtained with the commonly used bias-correction and spatial disaggregation (BCSD) approach, a modified version of BCSD which reverses the order of spatial disaggregation and bias-correction (SDBC), and the bias-correction and constructed analog (BCCA) method. Spatial and temporal statistics, transition probabilities, wet/dry spell lengths, spatial correlation indices, and variograms for wet (June through September) and dry (October through May) seasons were calculated for each method. Results showed that (1) BCCA underestimated mean daily precipitation for both wet and dry seasons while the BCSD, SDBC and BCSA methods accurately reproduced these characteristics, (2) the BCSD and BCCA methods underestimated temporal variability of daily precipitation and thus did not reproduce daily precipitation standard deviations, transition probabilities or wet/dry spell lengths as well as the SDBC and BCSA methods, and (3) the BCSD, BCCA and SDBC methods underestimated spatial variability in daily precipitation resulting in underprediction of spatial variance and overprediction of spatial correlation, whereas the new stochastic technique (BCSA) replicated observed spatial statistics for both the wet and dry seasons. This study underscores the need to carefully select a downscaling method that reproduces all precipitation characteristics important for the hydrologic system under consideration if local hydrologic impacts of climate variability and change are going to be reasonably predicted. For low-relief, rainfall-dominated watersheds, where reproducing small-scale spatiotemporal precipitation variability is important, the BCSA method is recommended for use over the BCSD, BCCA, or SDBC methods.

Seasonal variation of bat-flies (Diptera: Streblidae) in four bat species from a tropical dry forest

Mammalia ◽  
2018 ◽  
Vol 82 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Valeria B. Salinas-Ramos ◽  
Alejandro Zaldívar-Riverón ◽  
Andrea Rebollo-Hernández ◽  
L. Gerardo Herrera-M
Keyword(s):  
Seasonal Variation ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Significant Information ◽  
Bat Flies ◽  
Host Parasite Interactions ◽  
Dry Seasons ◽  
Bat Fly ◽  
Host Parasite ◽  
Wet And Dry Seasons

AbstractSeasonality of climate promotes differences in abundance and species composition of parasites, affecting host-parasite interactions. Studies have reported seasonal variation in bat-flies, which are obligate bat ectoparasites. We characterized the bat-fly load of three insectivores [Pteronotus davyi(Gray),Pteronotus parnellii(Gray) andPteronotus personatus(Wagner)] and one nectarivorous [Leptonycteris yerbabuenae(Martínez and Villa-R.)] bat species in a tropical dry forest to test the existence of seasonality in response to the availability of resources during the wet and dry seasons. We collected 3710 bat-fly specimens belonging to six species and two genera from 497 bats. Most of the ectoparasite load parameters examined (mean abundance, mean intensity, richness, etc.), including comparisons among reproductive conditions and sex of the host, were similar in both seasons. Prevalence was the parameter that varied the most between seasons. The six bat-fly species were found in all bat species exceptP. personatus. The latter species andL. yerbabuenaehad four and five bat-fly species in the wet and dry seasons, respectively. This study provides significant information of ectoparasites ecology in relation to seasonality, contributes to the understanding of host-parasite relationships in tropical dry forests and discusses the relevance of the abiotic and biotic factors that could impact host-parasite interactions.

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