Mapping species distributions as a tool in marine ecology

1978 ◽  
Vol 76 (1-3) ◽  
pp. 201-213 ◽  
Author(s):  
Trevor A. Norton
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Experimental Work ◽  
Current Velocity ◽  
Species Distributions ◽  
Distribution Patterns ◽  
Marine Species ◽  
Marine Ecology ◽  
Distribution Maps ◽  
Geographical Scale

SynopsisMaps are shown to be the most striking way of displaying the distribution of marine species on a geographical scale. They have been used to indicate not only the presence or absence of a species, but also its abundance. A single map only records the distribution pattern at a particular moment in time, but repeated mapping clearly demonstrates temporal fluctuations. Many ecological insights have been derived from distribution maps especially when they are compared with records of environmental factors such as substratum type, current velocity or temperature. Moreover maps actually stimulate experimental work which seeks to explain the distribution patterns displayed.

Ostracoda in Lake Illawarra: Environmental factors, assemblages and systematics.

1987 ◽  
Vol 38 (6) ◽  
pp. 795 ◽  
Author(s):  
I Yassini ◽  
BG Jones
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Water Depth ◽  
Intertidal Zone ◽  
New South ◽  
Marine Species ◽  
Seagrass Beds ◽  
South Wales ◽  
Lake Illawarra ◽  
Ostracod Species

Major controls of the distribution pattern and abundance of living ostracod populations in Lake Illawarra, a coastal lagoon south of Wollongong, New South Wales, are salinity and the benthic flora. The biocenotic ostracod assemblage from the intertidal zone around Windang Island is a typical, diverse, upper sublittoral, open ocean fauna. The lake entrance channel, which is a transport corridor for marine sediments into the lagoon, has a restricted ostracod biocenose (14 species) but contains an additional 72 species in the diverse thanatocenose resulting from the mixing of estuarine and marine species. Within the lagoon, the benthic flora influences the ostracod distribution pattern with the most diverse assemblage (13 species) occurring in areas covered by seagrasses. Seagrass distribution is, in turn, controlled by water depth, circulation, turbidity and substrate. Estuarine ostracods associated with the seagrass beds can tolerate florally induced fluctuations in pH from 7 to 10 and in dissolved oxygen from 1 mg l-1 to 14 mg l-1. In the deeper parts of the lagoon with a predominantly mud substrate, the ostracod assemblage is dominated by Osticythere reticulata. Most samples retrieved from the most polluted part of the lagoon contained no ostracods. A total of 90 ostracod species and subspecies belonging to 50 genera has been identified; nine species: Cytheralison cosmetics, Callistocythere janiceburrowsae, Callistocythere windangensis, Neocytherideis anneclarkeae, Actinocythereis robustus, Bradleya rectangulata, Procythereis jonesi, Hemicytherura windangensis and Cytheropteron wrighti; and one subspecies, Callistocythere dorsotuberculata paucicostata, are described as new to science.

THE INFLUENCE OF ENVIRONMENTAL FACTORS TO MOLLUSCS DISTRIBUTION PATTERNS IN NATURAL AND REHABILITATED MANGROVE ECOSYSTEM

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Andi Nur Samsi ◽  
Sharifuddin Bin Andy Omar ◽  
Andi Niartiningsih
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Quantitative Method ◽  
Distribution Patterns ◽  
Mangrove Ecosystem ◽  
Dispersal Patterns ◽  
Carbon And Nitrogen ◽  
Mangrove Ecosystems ◽  
Mollusc Species ◽  
Carbon And Nitrogen Content

Mangrove ecosystem is a habitat of Molluscs (Gastropoda and Bivalvia). This ecosystem is always influenced by environmental factors. This study aims to determine the influence of environmental factors on the distribution patterns Molluscs of natural mangrove ecosystems in Pannikiang Island, Barru Regency and rehabilitation mangrove ecosystem in Tongke-tongke village, Sinjai regency. This research uses the quantitative method. Environmental factors measured were temperature and salinity of the water, as well as carbon and nitrogen content of sediment. Samples of Molluscs (Gastropoda and Bivalves) and sediments were taken randomly. The observations of the Molluscan community include the composition of Mollusc species (Gastropoda and Bivalvia) and dispersal patterns. Data were analyzed by using multiple linear regression. The results showed that the distribution pattern of Molluscs (Gastropoda and Bivalvia) at both sites was not significantly different and the temperature, salinity, carbon, and nitrogen sediments also did not affect the Mollusk distribution pattern in both sites. Ekosistem mangrove merupakan habitat Moluska (Gastropoda dan Bivalvia). Ekosistem ini selalu dipengaruhi oleh faktor lingkungan. Penelitian ini bertujuan untuk mengetahui pengaruh faktor lingkungan terhadap pola distribusi  pada ekosistem mangrove alami di Pulau Pannikiang, Kabupaten Barru dan ekosistem mangrove hasil rehabilitasi di Desa Tongke-tongke, Kabupaten Sinjai. Penelitian ini menggunakan metode kuantitatif. Faktor lingkungan yang diukur adalah suhu dan  salinita air, serta kandungan karbon dan nitrogen sedimen. Sampel Moluska (Gastropoda dan Bivalvia) dan sedimen diambil secara acak. Pengamatan komunitas Moluska meliputi komposisi jenis Moluska (Gastropoda dan Bivalvia) dan pola penyebaran. Data dianalisis dengan menggunakan regresi linear berganda. Hasil penelitian menunjukkan pola distribusi Moluska (Gastropoda dan Bivalvia) pada kedua lokasi tidak berbeda nyata dan suhu, salinitas, karbon, dan nitrogen sedimen juga tidak mempengaruhi pola distribusi Moluska di kedua lokasi penelitian.

Intertidal meiofauna communities along an estuarine gradient in a protected area (Ria de Foz, north-west Spain)

2011 ◽  
Vol 92 (1) ◽  
pp. 63-72 ◽  
Author(s):  
M. Rubal ◽  
C. Besteiro ◽  
P. Veiga
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Social Services ◽  
Nature Reserve ◽  
Environmental Gradients ◽  
River Mouth ◽  
Distribution Patterns ◽  
Environmental Variable ◽  
North West ◽  
Estuarine Gradient

The northern Galician rias provide important economic and social services from fisheries, shellfish harvesting and recreational activities. Consequently, these rias have been included in the Nature 2000 Network as a Special Conservation Zone. The aims of this study were to describe the meiofauna spatial structure in terms of diversity and abundance of major taxa, as well as its relationship with the environmental characteristics in the Ria de Foz nature reserve. For this aim, environmental gradients and distribution patterns of intertidal meiobenthic communities at the Ria de Foz nature reserve were studied using multivariate methods. Ria de Foz showed to be a complex transitional habitat with significant changes in its environment along the estuarine gradient. An abundant and rich meiofauna community was reported at Ria de Foz. A total of 21 higher taxa of meiofauna were found. The most common taxa were nematodes, copepods, ostracods and turbellarians. Three clear different meiobenthic communities were defined. These three communities showed a clear spatial distribution pattern along the estuarine gradient. Moreover, a high degree of similarity between distribution patterns of meiobenthic communities and previously studied macrobenthic communities was found. Regarding the role of environmental factors shaping meiobenthic community distribution patterns distance to the river mouth was the environmental variable that best explained meiobenthic community structure and distribution. Therefore, changes on hydrodynamics that affect environmental factors related to the estuarine gradient will change the distribution pattern and diversity of benthic communities. This work provides the first information about meiobenthos diversity and structure in the Ria de Foz nature reserve and should be useful for future management and conservation plans on this and other similar protected areas.

scholarly journals Potential geographical distribution and environmental explanations of rare and endangered plant species through combined modelling: A case study of Northwest Yunnan, China

2020 ◽  
Author(s):  
Pengcheng Ye ◽  
Guangfu Zhang ◽  
Xiao Zhao ◽  
Hui Chen ◽  
Qin Si ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Geographical Distribution ◽  
Plant Species ◽  
Ecological Niche ◽  
Potential Distribution ◽  
Distribution Patterns ◽  
Endangered Plant ◽  
Rare And Endangered ◽  
Geographical Distribution Pattern

In recent decades, due to the effect of climate change and the interference of human activities, the species habitat index fallen 2%. Studying the geographical distribution pattern and predicting the potential geographical distribution of species are of great significance for developing scientific and effective biodiversity conservation strategies. The purpose of this research is to predict the potential geographical distribution of 25 rare and endangered plant species in Northwest Yunnan, China on the grid map with a resolution of 0.05° × 0.05° and analyze the explanation capabilities of various environmental factors on the potential geographical distribution patterns of these species, and explore the main restrictive environmental factors. Initially, we employed the ecological niche model MaxEnt to predict the potential geographical distribution of target species. Following that, we overlaid the potential geographical distribution of each species, and we obtained the potential geographical distribution pattern of species richness on the spatial scale of the ecological niche model with a resolution of 0.05° × 0.05°. Ultimately, we also adopted geographically weighted regression (GWR) model to investigate the explanation capabilities of various environmental parameters on the potential distribution patterns. The results showed that the average AUC value of each species was between 0.80 and 1.00, which indicated that the simulation precision of the MaxEnt model for each species was good or excellent. Besides, the potential distribution areas of these species were between 826.33 km2 and 44,963.53 km2. In addition, the average contribution values of the annual precipitation (Bio12), precipitation of coldest quarter (Bio19) and population density (Pop) were 25.92%, 15.86% and 17.95%, respectively. Moreover, the goodness of fit R2 and AIC value of the water model were 0.88 and 7,703.82, respectively, which indicated the water factor largely influenced the potential distribution of these species. The results of this study would be helpful for implementing long-term conservation and reintroduction for these species.

scholarly journals Combining fisheries surveys to inform marine species distribution modelling

2020 ◽  
Vol 77 (2) ◽  
pp. 539-552 ◽  
Author(s):  
Meadhbh Moriarty ◽  
Suresh A Sethi ◽  
Debbi Pedreschi ◽  
T Scott Smeltz ◽  
Chris McGonigle ◽  
...  
Keyword(s):  
Survey Data ◽  
Relative Abundance ◽  
Species Distribution ◽  
Distribution Patterns ◽  
Marine Species ◽  
Species Distribution Modelling ◽  
Distribution Maps ◽  
Modelling Framework ◽  
Combining Data ◽  
Gear Efficiency

Abstract Ecosystem-scale examination of fish communities typically involves creating spatio-temporally explicit relative abundance distribution maps using data from multiple fishery-independent surveys. However, sampling performance varies by vessel and sampling gear, which may influence estimated species distribution patterns. Using GAMMs, the effect of different gear–vessel combinations on relative abundance estimates at length was investigated using European fisheries-independent groundfish survey data. We constructed a modelling framework for evaluating relative efficiency of multiple gear–vessel combinations. 19 northeast Atlantic surveys for 254 species-length combinations were examined. Space-time variables explained most of the variation in catches for 181/254 species-length cases, indicating that for many species, models successfully characterized distribution patterns when combining data from disparate surveys. Variables controlling for gear efficiency explained substantial variation in catches for 127/254 species-length data sets. Models that fail to control for gear efficiencies across surveys can mask changes in the spatial distribution of species. Estimated relative differences in catch efficiencies grouped strongly by gear type, but did not exhibit a clear pattern across species’ functional forms, suggesting difficulty in predicting the potential impact of gear efficiency differences when combining survey data to assess species’ distributions and highlighting the importance of modelling approaches that can control for gear differences.

scholarly journals Study on Abundance and Distribution Pattern of Collembola on Three Types of Land Utilizations in Banjar Regency, South Kalimantan

2020 ◽  
Vol 5 (3) ◽  
pp. 107-117
Author(s):  
Manap Trianto ◽  
Fajri Marisa
Keyword(s):  
Environmental Factors ◽  
Distribution Pattern ◽  
Oil Palm ◽  
Sampling Method ◽  
Distribution Patterns ◽  
Sampling Location ◽  
Ecosystem Development ◽  
Soil Organism ◽  
Land Utilization ◽  
Abundance And Distribution

Collembola is one of soil organism which classified as mesofauna. This reseach is aims to study the abundance and distribution patterns of Collembola on three types of land utilization in Banjar District, South Kalimantan Province. This research was conducted on April 2020 by using a purposive sampling method. Based on results of Collembola identification obtained at the sampling location, there are 12 genera, 6 families, and 2 orders of Collembola. The highest abundance is found in oil palm plantations. While the Collembola distribution pattern on the three types of land clearing is the same, which is clustering. The results of this study are expected to provide information on the study of abundance and distribution patterns of Collembola in South Kalimantan Province related to environmental factors also help in carrying out sustainable ecosystem development.

Analisis Rantai Nilai Komoditas Cabai Merah

2019 ◽  
Vol 2 (1) ◽  
pp. 336-346
Author(s):  
Dhamon Oridilla B
Keyword(s):  
Distribution Pattern ◽  
Distribution Patterns ◽  
Added Value ◽  
Commodity Chain ◽  
Market Prices ◽  
Data Analyst ◽  
Bargaining Position ◽  
Agricultural Business ◽  
The Government ◽  
Red Peppers

Candi Village in Bandungan District is one of the Chili Supply Sub-district for Semarang Regency and surrounding area has agro-climate suitable for the development of various agricultural commodities supported by wide market opportunity, so it is suitable for agricultural business development. The purpose of this research is to identify the distribution pattern of red pepper, to know each value of commodity chains and distribution, to design alternative distribution pattern of red pepper.Population in this research is 88 respondents from 735 of member of chilli farmer in Desa Candi with total area of 150,3 hectare consisting of rice field, moor and yard. Methods of data analyst using quantitative approach is done by using Margin Marketing Analysis. The results include: (1) The pattern of distribution of existing farming business grows naturally in accordance with the developments and needs of the perpetrators, the actors in this pattern are farmers, wholesalers, collectors, wholesalers, retailers, consumers. (2) The value of the red chili commodity chain in this naturally grown pattern often makes pricing more dominant by traders, so farmers receive prices slightly lower than market prices. (3) Some obstacles faced in distributing red peppers are the difficulty of changing the mindset of the community about advanced farming, this is best utilized by market participants (chain of distribution) who are more informed and always keep abreast of market dynamics. Conventional marketing pattern by farmer cause price level accepted by farmer in general relatively smaller compared to price received by trader. Suggestions shorten the chain of distribution patterns, increase the added value of products and improve the bargaining position of farmers and for the government always guide / accompany farmers in getting accurate market information, which can be used as farmers in bargaining, Increased market transparency can act as a trigger for the functioning of a market, improved competition and increased adaptation to meet the needs of supply and opportunity to compete with market prices. Desa Candi di Kabupaten Bandungan adalah salah satu Kecamatan Penyedia Cabai untuk Kabupaten Semarang dan sekitarnya memiliki agroklimat yang cocok untuk pengembangan berbagai komoditas pertanian yang didukung oleh peluang pasar yang luas, sehingga sangat cocok untuk pengembangan bisnis pertanian. Tujuan dari penelitian ini adalah untuk mengidentifikasi pola distribusi cabai merah, untuk mengetahui masing-masing nilai rantai komoditas dan distribusi, untuk merancang alternatif pola distribusi cabai merah. Populasi dalam penelitian ini adalah 88 responden dari 735 anggota petani cabai di Desa Candi dengan total luas 150,3 hektar yang terdiri dari sawah, tegalan dan pekarangan. Metode analis data menggunakan pendekatan kuantitatif dilakukan dengan menggunakan Analisis Pemasaran Margin. Hasil meliputi: (1) Pola distribusi usaha pertanian yang ada tumbuh secara alami sesuai dengan perkembangan dan kebutuhan pelaku, pelaku dalam pola ini adalah petani, pedagang besar, pengumpul, pedagang besar, pedagang besar, pengecer, konsumen. (2) Nilai rantai komoditas cabai merah dalam pola yang dikembangkan secara alami ini sering membuat penetapan harga lebih dominan oleh para pedagang, sehingga petani menerima harga yang sedikit lebih rendah daripada harga pasar. (3) Beberapa kendala yang dihadapi dalam mendistribusikan paprika merah adalah sulitnya mengubah pola pikir masyarakat tentang pertanian maju, hal ini paling baik digunakan oleh pelaku pasar (rantai distribusi) yang lebih banyak informasi dan selalu mengikuti perkembangan dinamika pasar. Pola pemasaran konvensional oleh petani menyebabkan tingkat harga yang diterima petani pada umumnya relatif lebih kecil dibandingkan dengan harga yang diterima pedagang. Saran mempersingkat rantai pola distribusi, meningkatkan nilai tambah produk dan meningkatkan posisi tawar petani dan bagi pemerintah selalu membimbing / menemani petani dalam mendapatkan informasi pasar yang akurat, yang dapat digunakan sebagai petani dalam tawar-menawar, Peningkatan transparansi pasar dapat bertindak sebagai pemicu berfungsinya pasar, meningkatnya kompetisi dan peningkatan adaptasi untuk memenuhi kebutuhan pasokan dan peluang untuk bersaing dengan harga pasar.

scholarly journals Computing infection distributions and longitudinal evolution patterns in lung CT images

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dongdong Gu ◽  
Liyun Chen ◽  
Fei Shan ◽  
Liming Xia ◽  
Jun Liu ◽  
...  
Keyword(s):  
Time Course ◽  
Lower Lobe ◽  
Ground Truth ◽  
Distribution Patterns ◽  
Lung Infection ◽  
Ct Images ◽  
Community Acquired Pneumonia ◽  
Disease Course ◽  
Distribution Maps ◽  
Significant Difference

Abstract Background Spatial and temporal lung infection distributions of coronavirus disease 2019 (COVID-19) and their changes could reveal important patterns to better understand the disease and its time course. This paper presents a pipeline to analyze statistically these patterns by automatically segmenting the infection regions and registering them onto a common template. Methods A VB-Net is designed to automatically segment infection regions in CT images. After training and validating the model, we segmented all the CT images in the study. The segmentation results are then warped onto a pre-defined template CT image using deformable registration based on lung fields. Then, the spatial distributions of infection regions and those during the course of the disease are calculated at the voxel level. Visualization and quantitative comparison can be performed between different groups. We compared the distribution maps between COVID-19 and community acquired pneumonia (CAP), between severe and critical COVID-19, and across the time course of the disease. Results For the performance of infection segmentation, comparing the segmentation results with manually annotated ground-truth, the average Dice is 91.6% ± 10.0%, which is close to the inter-rater difference between two radiologists (the Dice is 96.1% ± 3.5%). The distribution map of infection regions shows that high probability regions are in the peripheral subpleural (up to 35.1% in probability). COVID-19 GGO lesions are more widely spread than consolidations, and the latter are located more peripherally. Onset images of severe COVID-19 (inpatients) show similar lesion distributions but with smaller areas of significant difference in the right lower lobe compared to critical COVID-19 (intensive care unit patients). About the disease course, critical COVID-19 patients showed four subsequent patterns (progression, absorption, enlargement, and further absorption) in our collected dataset, with remarkable concurrent HU patterns for GGO and consolidations. Conclusions By segmenting the infection regions with a VB-Net and registering all the CT images and the segmentation results onto a template, spatial distribution patterns of infections can be computed automatically. The algorithm provides an effective tool to visualize and quantify the spatial patterns of lung infection diseases and their changes during the disease course. Our results demonstrate different patterns between COVID-19 and CAP, between severe and critical COVID-19, as well as four subsequent disease course patterns of the severe COVID-19 patients studied, with remarkable concurrent HU patterns for GGO and consolidations.

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