Distribution of intertidal benthic algae in the vicinity of Townsville, tropical Australia

1980 ◽  
Vol 31 (2) ◽  
pp. 175 ◽  
Author(s):  
Y Ngan ◽  
IR Price
Keyword(s):  
Animal Species ◽  
Benthic Algae ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Vertical And Horizontal Distribution ◽  
Tropical Australia ◽  
Marine Algal

The vertical and horizontal distribution of 144 benthic marine algal taxa (25 of the Chlorophyta, 21 of the Phaeophyta, 92 of the Rhodophyta and 6 of the Cyanophyta) in the intertidal region in the vicinity of Townsville was investigated. The distribution patterns are discussed in relation to the zonation of animal species in the region and compared with information available for other tropical shores.

Size divergence and dietary partitioning enhance coexistence of two herbivorous species of Diaptomus (Copepoda: Calanoida) in some shallow Quebec lakes

1992 ◽  
Vol 70 (5) ◽  
pp. 1016-1028 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Edward J. Maly
Keyword(s):  
Distribution Patterns ◽  
Significant Negative Correlation ◽  
Geographic Region ◽  
Horizontal Distribution ◽  
Sympatric Populations ◽  
Blue Green Algae ◽  
Diet Preference ◽  
Diaptomus Oregonensis ◽  
Vertical And Horizontal Distribution ◽  
Herbivorous Species

We examined the vertical and horizontal distribution patterns of Diaptomus minutus Lilljeborg and Diaptomus oregonensis Forbes in several shallow Quebec lakes where they occurred allopatrically and sympatrically within a small geographic region. Both species overlapped extensively in their vertical and temporal distributions and were found to be positively associated within and among lakes. Although size displacement could not be detected when body lengths of sympatric and allopatric populations were compared, in lakes where there was a reduction in size overlap between species, the two species coexisted at relatively high densities. This contrasted with situations where convergence in size between species was accompanied by a limited abundance of one or both diaptomids. We conducted stomach-content analyses on the sympatric populations of two of these lakes to determine if diet preference was related to copepod size divergence, and if algae were selected as a function of copepod size. We found that D. minutus, the smaller copepod, preferentially ingested a number of small algal particles (< 10 μm), whereas D. oregonensis, the larger copepod, tended to ingest a greater number of larger particles. Although preference for small algae (Selenastrum and small blue–green algae) was negatively correlated with prosome length, preference for larger algal taxa (Planktosphaerium, centric diatoms such as Melosira, and Achnanthes) was positively correlated with diaptomid size. There were, however, differences with respect to the degree of diet overlap between species in the two lakes, which was reflected in a significant negative correlation between dietary and size overlap. These observations are consistent with the hypothesis that reduction in size overlap has resulted in reduced exploitative competition, and that divergence in size and diet may be the mechanism that allows D. minutus and D. oregonensis to coexist when food becomes limiting.

scholarly journals Spatial distribution by Canistropsis microps (E. Morren ex Mez) Leme (Bromeliaceae: Bromelioideae) in the Atlantic rain forest in Ilha Grande, Southeastern Brazil

2007 ◽  
Vol 67 (3) ◽  
pp. 467-474 ◽  
Author(s):  
AF. Nunes-Freitas ◽  
CFD. Rocha
Keyword(s):  
Rain Forest ◽  
Vegetative Reproduction ◽  
Inverse Correlation ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
High Rate ◽  
Southeastern Brazil ◽  
Atlantic Rain Forest ◽  
Maximum Height ◽  
Vertical And Horizontal Distribution

Canistropsis microps (Bromeliaceae: Bromelioideae) is an endemic species of Atlantic rain forest areas in Rio de Janeiro State, which are very abundant in not very disturbed forests in Ilha Grande, on the southern coast of the State. In this study, we analyzed the vertical and horizontal distribution patterns of the species in an area of rain forest with little evidence of disturbance at Vila Dois Rios, Ilha Grande, relating the patterns to sunlight in the microhabitat. We also identified the types of substrate used by the species and the rate of asexual reproduction. Canistropsis microps had high densities (estimated at 84,425 rosettes/ha), and has an aggregated distribution (Id = 2.86). About 80% of the rosettes were generated by clonal growth, whereas less than 20% were produced from seedlings. Most of the rosettes were found on straight tree trunks (DBH > 50 cm). There was a significant inverse correlation between the incidence of sunlight in the habitat and the abundance of individuals. Rosettes were found up to a maximum height of 9.5 m, but most occured between 1.5 and 5.5 m, where light varied from 25 to 50 µmol.s-1.m-2. We conclude that vertical and horizontal distribution patterns in C. microps may be partially explained by the occurrence of appropriate substrate, an intensity of sunlight favorable to the development of the species and to a high rate of vegetative reproduction.

Mesoscale Aggregations of Euphausiid Sound Scattering Layers on the Continental Shelf of Vancouver Island

1989 ◽  
Vol 46 (7) ◽  
pp. 1238-1249 ◽  
Author(s):  
Yvan Simard ◽  
David L. Mackas
Keyword(s):  
Continental Shelf ◽  
High Frequency ◽  
Dry Weight ◽  
Distribution Patterns ◽  
Vancouver Island ◽  
Horizontal Distribution ◽  
Swimming Behavior ◽  
Shelf Break ◽  
Shelf Area ◽  
Vertical And Horizontal Distribution

High frequency acoustics (104 kHz) and stratified (BIONESS) net tows were used to map the vertical and horizontal distribution of macrozooplankton scattering layers on and seaward of the continental shelf off Vancouver Island, in June and August of 1986. The macrozooplankton scattering layers were dominated by euphausiids, primarily Euphausia pacifica and Thysanoessa spinifera. During both surveys, dense aggregations were found in the same two general regions. The first was along the shelf break, where highest biomass was observed (averages over a few kilometres of transect reaching to about 200 mg dry weight∙m−3 = about 40 individuals∙m−3 and > 4 g dry weight∙m−2). A second, broader and more diffuse aggregation occupied the deeper southeast end of the shelf (area about 200 km2, biomass 1–2 g∙m−2). The scattering layers showed a consistent diel vertical migration. Daytime depth was deeper at the shelf break (~ 150–200 m) than on the shelf (~ 100–150 m) and occasionally extended to the bottom. These day-depths corresponded to the California Undercurrent waters of 6–7 °C, a salinity of 33.75–34‰ and sigma-T > 26.5. Distribution patterns were coincident with those of upwelled regions, high phytoplankton biomass, and high hake and herring biomass. They were also associated with the shelf break jet and the recurrent Tully eddy. There is a strong possibility of aggregation in restricted areas through the coupling of advection and vertical swimming behavior of the animals.

scholarly journals Vegetation Height and Diurnal Period Influenced the Landscape-Use Pattern of Small Ruminants in Woodlands around Summer

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 205
Author(s):  
Shailes Bhattrai ◽  
Uma Karki ◽  
Sanjok Poudel
Keyword(s):  
Feeding Behavior ◽  
Animal Species ◽  
Small Ruminants ◽  
Ground Level ◽  
Distribution Patterns ◽  
Control Area ◽  
Weather Data ◽  
Vegetation Height ◽  
Understory Shrubs ◽  
Diurnal Period

Despite the huge potential of using woodlands for small ruminant grazing in the southeast US, unmanaged understory shrubs grown beyond animals’ access minimize the utilization of such vegetation. This study aimed to determine the effect of vegetation height and diurnal period on the behavior and distribution patterns of goats and sheep in woodlands around summer. The study was conducted in six woodland plots (0.4 ha each) comprising southern pines and non-pine (non-target) plant species. Non-pine plants in each study plot were assigned to four treatments: cut to 0 m, 0.9 m, or 1.5 m from the ground level or left uncut (control). Cut plant stubs were allowed to regrow to full canopy before stocking animals. Eight Kiko wethers and five Katahdin rams were rotationally stocked in separate plots, and their diurnal (dawn–dusk) behaviors and distribution patterns were monitored when they were in each plot (three plots per animal species) around the summer of 2018. Animal behavior data were analyzed using the general linear model (GLM) procedure with multivariate analysis of variance (MANOVA) in SAS, while animal distribution pattern and weather data were analyzed in SAS using a GLM procedure and the distribution evenness index (DEI) using the Kruskal–Wallis rank-sum test in R. Level of significance was set at 5%. Both animal species visited the control area the least. Wethers browsed predominantly in areas where non-pine plants were cut to 0.9 m from the ground level, and rams grazed mostly in areas where non-pine plants were cut to the ground level, mostly during the post-midday period. Browsing was the dominant feeding behavior of wethers (39% browsing vs. 4% grazing), while rams’ feeding behavior was dominated with grazing (24% grazing vs. 12% browsing). Lying was a predominant diurnal behavior in both wethers (46%) and rams (35%), mostly during the midday period. Wethers had a higher value for DEI than rams during the morning and post-midday periods. This study established that (1) the utilization of woodland understory foliage by small ruminants can be increased by lowering plant height, and (2) both vegetation characteristics and diurnal period are important factors for influencing small ruminants’ behavior while stocked in woodlands around summer.

scholarly journals Defining and Characterising Clusters in Palaeolithic Sites: a Review of Methods and Constraints

2021 ◽  
Author(s):  
Laura Sánchez-Romero ◽  
Alfonso Benito-Calvo ◽  
Joseba Rios-Garaizar
Keyword(s):  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Spatial Studies ◽  
Innovative Methods ◽  
General Terms ◽  
Fabric Analysis ◽  
Gis Tools ◽  
Definition Of ◽  
Intentional Activities ◽  
Statistical Criteria

AbstractSpatial analysis studies in Palaeolithic archaeology arise as indispensable research tools for understanding archaeopalaeontological sites. In general terms, spatial studies have been specialised in the description of the distribution of materials and in the definition of accumulation areas, with the aim of distinguishing intentional activities or studying postdepositional processes. In recent decades, the development of GIS tools has enabled huge strides forward in the field of spatial archaeology research, such as spatial inferential statistics. These tools are particularly useful in the identification and location of clustering from statistical criteria, facilitating the subsequent analysis of accumulations through other archaeological, taphonomic and spatial techniques, such as fabric analysis or directional distribution. The cluster analysis, and its contextualisation considering all the archaeological and stratigraphical variables, allows the inference of some of the processes and factors that could have taken part in the accumulation of materials, as well as assessing how this affected the composition and preservation of the archaeological assemblage. The present article reviews the more traditional and innovative methods for studying horizontal distribution patterns and the objective definition of clusters, highlighting the parameters, uses and limitations of these techniques. We present an application of these methods to different Palaeolithic sites, going through different scenarios, such as location (open-air vs. cave), context, scale (large vs. small area), excavation methodology and spatial record methods.

Behavior and Distribution of Nonylphenol Ethoxylates and their Metabolites in Sediments of Nansi Lake, China

2011 ◽  
Vol 356-360 ◽  
pp. 1733-1738
Author(s):  
Fang He ◽  
Aya Obara ◽  
Shi Long Wang ◽  
Li Guo Wang
Keyword(s):  
Water Flow ◽  
Flow Direction ◽  
Sediment Cores ◽  
Sewage Treatment ◽  
Vertical Direction ◽  
Total Content ◽  
Horizontal Distribution ◽  
Nansi Lake ◽  
Increasing Trend ◽  
Vertical And Horizontal Distribution

The vertical and horizontal distribution of NPEOn and their metabolites of NP and NPEnC in the Upper Nansi Lake, North China were investigated using LC-MS and LC-MS/MS methods, sampling at three sites (St.1, St.2 and St.3) along the water flow direction. The total content of NPEOn (n=1–15) bound onto the sediment of this lake changed in the range of 60.7–631.5 μg/kg-dry with the horizontal flow direction and the vertical direction of the sediment cores with sediment thickness up to 35 cm. Compared to the presence levels of all detected NPEOn species, the content of NP was much higher, falling in 26.5–1,998.4 μg/kg-dry. A general increasing trend of the NP content along the water flow direction of this lake was revealed. NPEnC showed a roughly increasing trend from the upstream to the downstream, with the total concentrations being obviously lower than NPEOn and NP and falling in 2.13–23.1 μg/kg-dry. The short chain NPEOn dominant in NPEO mixtures in these sedimentary cores indicated that this lake received some effluents from STPs, and the sewage treatment ratio is relatively low in this area. Furthermore, the computed magnitudes of NPEO 1-2/NPEO1-15, NP/NPEO 1-15 and NPEC 1-10/NPEO 1-15 suggested that the non-oxidative hydrolytic transformation seemed to be a major process occurring within the sediment phase of Nansi Lake, while the oxidative hydrolytic transformation pathway was probably less involved.

scholarly journals Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest

2013 ◽  
Vol 85 (2) ◽  
pp. 727-736 ◽  
Author(s):  
GERUZA L. MELO ◽  
BARBARA MIOTTO ◽  
BRISA PERES ◽  
NILTON C. CACERES
Keyword(s):  
Habitat Selection ◽  
Small Mammals ◽  
Strong Evidence ◽  
Animal Species ◽  
Deciduous Forest ◽  
Distribution Patterns ◽  
Microhabitat Use ◽  
Southern Brazil ◽  
Different Types ◽  
Didelphis Albiventris

Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.

scholarly journals Animal rabies epidemiology in Nepal from 2005 to 2017

2021 ◽  
pp. 190-195
Author(s):  
Pushkar Pal ◽  
Adisorn Yawongsa ◽  
Rajesh Bhatta ◽  
Hiroshi Shimoda ◽  
Theera Rukkwamsuk
Keyword(s):  
Animal Species ◽  
Central Zone ◽  
Distribution Patterns ◽  
Domestic Animals ◽  
Population Management ◽  
Regional Level ◽  
Development Zone ◽  
Ecological Zones ◽  
Veterinary Laboratory ◽  
Agro Ecological Zones

Background and Aim: Animal rabies is endemic in Nepal, and it occurs in two forms. Although governmental and non-governmental agencies are working toward the control of rabies by mass dog vaccination and stray dog population management, there is still massive number of rabies incidence reported to the reference veterinary laboratory, Nepal. Therefore, this study aimed to assess animal species, temporal, regional, and agro-ecological distribution patterns of animal rabies in Nepal from 2005 to 2017. Materials and Methods: The epidemiological data on animal rabies from the period of 2005 to 2017 were obtained from the Central Veterinary Laboratory, Tripureshwor, Kathmandu, Nepal. The laboratory-confirmed rabies cases were analyzed according to animal species, temporal, regional (developmental zones), and agro-ecological distributions. In addition, descriptive statistics were used to evaluate the distribution patterns of rabies. Results: From 2005 to 2017, a total of 2771 suspected rabies cases in animals were reported to The Central Veterinary Hospital, Kathmandu. Of which, 1302 were found laboratory-confirmed cases. The rabies cases were most commonly reported and confirmed in dogs followed by other domestic animals. The high occurrences were recorded between 2005 and 2007. However, the incidence was increased during 2016 and 2017. The highest number of rabies cases was recorded in the eastern development zone, and the least number in the central zone at regional level. Likewise, it was highest in the Terai (plain) region and lowest in mountainous areas at agro-ecological zones. The findings also revealed that the occurrences of rabies significantly differed among seasons. Conclusion: Rabies is present in Nepal throughout the year and all seasons with seasonal variation. Among the animal species, dogs are the primary animals affected with rabies followed by cattle and other domestic animals. At the regional level, eastern development zone had the highest incidence and Central development zone recorded the least. Similarly, the Terai region had the highest incidence rates, and the least overall prevalence rate was observed in mountainous regions among agro-ecological zones. Therefore, the government should implement the strict enforcement of mass dog vaccination and dog population management through one health approach to control rabies incidence in the country.

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