scholarly journals Getting to the Point: Accuracy of Point Count in Monitoring Ecosystem Change

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Eric Pante ◽  
Phillip Dustan
Keyword(s):  
Ecological Monitoring ◽  
Careful Consideration ◽  
Ecosystem Change ◽  
Percent Cover ◽  
Optimal Point ◽  
Point Count ◽  
Video Imagery ◽  
Coral Reef Ecosystems ◽  
Minimum Number ◽  
Lower Cover

Ecological monitoring programs depend on the robust estimation of descriptive parameters. Percent cover, gleaned from transects sampled with video imagery, is a popular benthic ecology descriptor often estimated using point counting, an image-based method for identifying substrate types beneath random points. We tested the hypothesis that the number of points needed to robustly estimate benthic cover in video imagery transects depends on cover itself, predicting that lower cover will require more points/frame to be accurately estimated. While this point may seem obvious to the statistically inclined, the justification of point density has been largely ignored in the literature. We examined the statistical behavior of point count estimates using computer-simulated 20 m-long transects patterned after data from a Bahamian reef. The minimum number of points necessary to insure accurate percent cover estimation, the Optimal Point Count (OPC), is a function of mean percent cover and spatial heterogeneity of the benthic community. More points are required to characterize reefs with lower cover and more homogeneously distributed coral colonies. These results show that careful consideration must be given to sampling design and data analysis prior to attempting to estimate benthic cover, especially in the context of long-term monitoring of degrading coral reef ecosystems.

Occurrence and Distribution of an Invasive Octocoral, Carijoa riisei in Malaysia’s Marine Park of Pulau Payar

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Normah S ◽  
◽  
Ismail MS ◽  
Md. Nizam I ◽  
Zaidnuddin I ◽  
...  
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Diversity Indices ◽  
Percent Cover ◽  
Point Count ◽  
Marine Park ◽  
Wide Range ◽  
Remedial Actions ◽  
Carijoa Riisei ◽  
Study Sites

The occurrence of the invasive snowflake coral, Carijoa riisei (Duchassaing & Michelotti, 1860) in Malaysian waters was reported after the species was first detected at Pulau Payar Marine Park in 2014. Its recent appearance in Pulau Payar highlights the need for baseline data concerning the distribution pattern and diversity of C. riisei within the Pulau Payar Marine Park and may enable effective remedial actions in controlling the overgrowth of this octocoral. The snowflake coral and other substrates were quantified over quadrats located randomly on a 50 m transects in three study sites, i.e. Coral Garden, Kaca Reef and Lembu Rock. The percent cover of each substrate category and diversity were determined using the Coral Point Count with Excel extensions (CPCe) software. The snowflake coral was most frequently observed at the depths of 10 to 20 m at each of the study sites. The area with highest coverage of this octocoral was in Kaca Reef at the depth of 20m. About one-third of the benthos and abiotic substrate at all sites was populated by C. riisei. Statistically, no significant differences were found between the distributions of C. riisei by sites. Using diversity indices, we were able to demonstrate the ability of this species to exploit a wide range of differing environments. This ability has allowed it to spread within this marine protected area. Based on this study, we suggested monitoring programs should be regularly conducted within Pulau Payar Marine Park, other reefs should be surveyed for its presence, and an effective mitigation program should be developed for the conservation of the marine ecosystems affected by this invasive species.

scholarly journals Kajian Kondisi dan Nilai Ekonomi Manfaat Ekosistem Terumbu Karang di Pantai Wediombo, Kabupaten Gunung Kidul, Daerah Istimewa Yogyakarta

2016 ◽  
Vol 14 (2) ◽  
pp. 82
Author(s):  
Heriawan Maulana ◽  
Sutrisno Anggoro ◽  
Bambang Yulianto
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Common Property ◽  
Economic Valuation ◽  
Economic Value ◽  
Survey Method ◽  
Economic Losses ◽  
Percent Cover ◽  
Coral Reef Ecosystems ◽  
Line Intercept

ABSTRAKPerairan Wediombo Kabupaten Gunung Kidul yang telah ditetapkan sebagai Pencadangan Kawasan Konservasi Perairan Daerah pada tahun 2013. Pemanfaatan wilayah Pantai Wediombo oleh masyarakat sebagai lokasi pendaratan ikan dan pariwisata mengakibatkan peningkatan tekanan terhadap ekosistem perairan khususnya terumbu karang. Sebagai common property, kerusakan ekosistem terumbu karang tidak dirasakan sebagai kerugian ekonomi sehingga eksploitasi dari manfaat ekosistem terumbu karang menjadi tidak terkendali. Pengelolaan Pantai Wediombo menjadi tantangan bagi stakeholder untuk dapat mengoptimalkan pemanfaatan jasa lingkungan bagi kesejahteraan masyarakat. Salah satu komponen upaya pengelolaannya yaitu dengan melakukan pemantauan kondisi terumbu karang di Pantai Wediombo. Valuasi ekonomi ekosistem termbu karang merupakan instrumen untuk menilai produk dan jasa yang dihasilkan oleh ekosistem terumbu karang. Tujuan dari penelitian ini adalah untuk mengetahui kondisi ekosistem terumbu karang yang diwakili oleh persen tutupan terumbu karang dan nilai manfaat ekosistem terumbu karang yang diwakili oleh produk perikanan yang dihasilkan dari ekosistem terumbu karang di Pantai Wediombo. Metode yang digunakan adalah metode survei. Metode pengumpulan data kondisi terumbu karang mengacu pada metode Line Intercept Transect (LIT). sedangkan nilai ekonomi manfaat ekosistem terumbu karang dihitung menggunakan metode Effect on Productivity. Pada penelitian diperoleh hasil prosentase tutupan terumbu karang di Pantai Wediombo sebesar 25,29% dengan status kondisi rusak sedang. nilai ekonomi aktual ekosistem terumbu karang di Pantai Wediombo sebesar Rp. 634.553.504,-, sedangkan nilai manfaat sekarang dari ekosistem terumbu karang di Pantai Wediombo sebesar Rp. 20.304.872,-.Kata kunci: Ekosistem Terumbu Karang, Valuasi Ekonomi, Pantai Wediombo ABSTRACTBodies Wediombo Gunung Kidul regency which has been designated as a Local Backup Water Conservation Area in 2013. Utilization Wediombo Turkish territory by the public as a fish landing site and tourism resulted in increased pressure on aquatic ecosystems, especially coral reefs. As common property, damage to coral reefs is not perceived as economic losses so that the exploitation of the benefits of coral reef ecosystems had become unmanageable. Wediombo Coastal management is a challenge for stakeholders to be able to optimize the use of environmental services for the welfare of society. One component management efforts is by monitoring the condition of coral reefs in Wediombo Beach. Economic valuation of coral ecosystems termbu is an instrument to assess the products and services produced by a coral reef ecosystems. The purpose of this study was to determine the condition of coral reef ecosystems are represented by percent cover of coral reefs and coral reef ecosystems benefit value represented by the fishery products produced from coral reef ecosystems Wediombo Beach. The method used is a survey method. Methods of data collection coral reef condition refers to a method Line Intercept Transect (LIT). while the economic value of coral reef ecosystem benefits are calculated using methods Effect on Productivity. In the research results the percentage of coral reef cover in Turkish Wediombo of 25.29% with a damaged condition status. the true economic value of coral reef ecosystems Wediombo Coast of Rp. 634 553 504, -, while the value of current benefits of coral reef ecosystems Wediombo Coast of Rp. 20,304,872, -.Keywords:  Coral Reef Ecosystems, Economic Valuation, Turkish WediomboCara sitasi: Maulana, H., Anggoro, S., Yulianto, B. (2016). Kajian Kondisi dan Nilai Ekonomi Manfaat Ekosistem Terumbu Karang di Pantai Wediombo, Kabupaten Gunung Kidul, Daerah Istimewa Yogyakarta. Jurnal Ilmu Lingkungan,14(2),82-87, doi:10.14710/jil.14.2.82-87

scholarly journals Abundance of Black-backed Woodpeckers and other birds in relation to disturbance and forest structure in the Black Hills and Bear Lodge Mountains of South Dakota and Wyoming

2017 ◽  
Author(s):  
◽  
Elizabeth A. Matseur
Keyword(s):  
South Dakota ◽  
Detection Probability ◽  
Information Criterion ◽  
R Package ◽  
Black Hills ◽  
Percent Cover ◽  
Point Count ◽  
Dead Trees ◽  
Species Population ◽  
Percent Area

Black-backed Woodpeckers (Picoides arcticus) are rare residents of northern conifer forests and are almost always associated with disturbances, such as fire and beetle infestation. The Black Hills population of Black-backed Woodpeckers has been petitioned to be considered a Distinct Population Segment under the Endangered Species Act and more information on their population size in the region is needed. Our objective was to map abundance of Black-backed Woodpeckers in the Black Hills and Bear Lodge Mountains of South Dakota and Wyoming and provide a population estimate for Black-backed Woodpeckers in the region. We located 124 and 115 transects, containing 1,232 and 1,138 sampling points, in 2015 and 2016, respectively. We conducted 5-minute point count surveys from late-March to late-June and visited each point three times to estimate detection probability. We characterized vegetation around each point using GIS derived landscape variables that included: percent cover of green trees, beetle killed trees, dead trees, and year since wildfire. We detected 362 Black-backed Woodpeckers across both years. We fit three-level hierarchical time-removal models that simultaneously estimated abundance, availability, and detection probability in R package "unmarked" using gmultmix and ranked models using Akaike Information Criterion. The global abundance model received the most support. Abundance was negatively related to percent cover of dead trees and green trees and a positively related to percent cover of beetle killed trees, and percent area of 1- to 2-, 3-, and 4- to 5-year-old wildfires. Abundance of Black-backed Woodpeckers varied the greatest across present cover of beetle killed trees and wildfires that had burned within the last five years. Mean density was 0.00528 birds/ha in 2015 and 0.00626 birds /ha in 2016. An estimated 2,920 (LCL: 1,449; UCL: 5,917) and 3,439 (LCL: 1,739; UCL: 6,908) individual Black-backed Woodpeckers, which is equivalent to 1,460 and 1,720 pairs of Black-backed Woodpeckers, in the Black Hills in 2015 and 2016, respectively. Our study is the most extensive survey of Blackbacked Woodpecker abundance in the region and sets the stage for future analyses of the species population viability in the region.

scholarly journals Status Terkini Tutupan Terumbu Karang di Perairan Dangkal Pulau Bedil, Desa Labuan Bajo, Kabupaten Sumbawa, NTB

2021 ◽  
pp. 243-253
Author(s):  
Mahardika Rizqi Himawan ◽  
Eni Hidayati ◽  
Nurliah Buhari ◽  
Sitti Hilyana ◽  
Maulita Syahdina
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Small Island ◽  
Percent Cover ◽  
Coral Mortality ◽  
Dead Coral ◽  
The North ◽  
Mortality Index ◽  
Coral Reef Ecosystems ◽  
Index Value

Bedil Island is included in the Keramat, Bedil, and Temudong Small Island Park (TPK), which was approved by the Regent of Sumbawa. Administratively, this island is included in the Labuan Bajo Village area, Sumbawa, NTB. There is the existence of coral reef ecosystems in these waters that form a reef flat and reef slope profile, that stretches to the southwest and northeast. By its designation as a small island park, the coral reefs in Bedil Island are used as an underwater tourism object. This study aims to determine the current condition of coral reef cover in the waters around Bedil Island, especially in the eastern and southern parts of the island. Coral reefs in the north and west area are limited and there is the existence of seagrass beds. The line intercept transect method is carried out by spreading the roll meter as far as 50 meters on the east and south sides of the island with a depth of 2-3 meters. The coral lifeform that is tangent with the roll meter is then recorded and then analyzed for the average percent cover, clustering status, and coral mortality index. Coral reefs in the eastern and southern parts of Bedil Island are classified as very good/excellent because they have a percent cover value above 75%. In addition, the coral mortality index value is also relatively small which indicates that the corals are living well. Clearwater conditions and locations far from human settlements are thought to be factors that support coral survival. However, the presence of dead coral algae and rubble still indicates a threat of damage even though the value is small. Algae life on the surface of dead coral also indicates that the coral has been dead for a long time. 

scholarly journals Nutrient and sediment loading affect multiple facets of functionality in a tropical branching coral

2020 ◽  
Vol 223 (21) ◽  
pp. jeb225045
Author(s):  
Danielle M. Becker ◽  
Nyssa J. Silbiger
Keyword(s):  
Coral Reef ◽  
Nitrogen Content ◽  
Thermal Performance ◽  
Nutrient Loading ◽  
Metabolic Responses ◽  
Coral Host ◽  
Percent Cover ◽  
Sediment Loading ◽  
Anthropogenic Stressors ◽  
Coral Reef Ecosystems

ABSTRACTCoral reefs, one of the most diverse ecosystems in the world, face increasing pressures from global and local anthropogenic stressors. Therefore, a better understanding of the ecological ramifications of warming and land-based inputs (e.g. sedimentation and nutrient loading) on coral reef ecosystems is necessary. In this study, we measured how a natural nutrient and sedimentation gradient affected multiple facets of coral functionality, including endosymbiont and coral host response variables, holobiont metabolic responses and percent cover of Pocillopora acuta colonies in Mo′orea, French Polynesia. We used thermal performance curves to quantify the relationship between metabolic rates and temperature along the environmental gradient. We found that algal endosymbiont percent nitrogen content, endosymbiont densities and total chlorophyll a content increased with nutrient input, while endosymbiont nitrogen content per cell decreased, likely representing competition among the algal endosymbionts. Nutrient and sediment loading decreased coral metabolic responses to thermal stress in terms of their thermal performance and metabolic rate processes. The acute thermal optimum for dark respiration decreased, along with the maximal performance for gross photosynthetic and calcification rates. Gross photosynthetic and calcification rates normalized to a reference temperature (26.8°C) decreased along the gradient. Lastly, percent cover of P. acuta colonies decreased by nearly two orders of magnitude along the nutrient gradient. These findings illustrate that nutrient and sediment loading affect multiple levels of coral functionality. Understanding how local-scale anthropogenic stressors influence the responses of corals to temperature can inform coral reef management, particularly in relation to the mediation of land-based inputs into coastal coral reef ecosystems.

Information capacity and bandwidth limitations in the SEM

1989 ◽  
Vol 47 ◽  
pp. 84-85
Author(s):  
D. C. Joy ◽  
R. D. Bunn
Keyword(s):  
Signal To Noise Ratio ◽  
Critical Dimension ◽  
Information Capacity ◽  
Acquisition Time ◽  
Signal To Noise ◽  
Sem Image ◽  
Probe Size ◽  
Minimum Number ◽  
Noise Ratio ◽  
Signal Channel

The information available from an SEM image is limited both by the inherent signal to noise ratio that characterizes the image and as a result of the transformations that it may undergo as it is passed through the amplifying circuits of the instrument. In applications such as Critical Dimension Metrology it is necessary to be able to quantify these limitations in order to be able to assess the likely precision of any measurement made with the microscope.The information capacity of an SEM signal, defined as the minimum number of bits needed to encode the output signal, depends on the signal to noise ratio of the image - which in turn depends on the probe size and source brightness and acquisition time per pixel - and on the efficiency of the specimen in producing the signal that is being observed. A detailed analysis of the secondary electron case shows that the information capacity C (bits/pixel) of the SEM signal channel could be written as :

Applying Generalizability Theory to Optimize Analysis of Spontaneous Teacher Talk in Elementary Classrooms

2020 ◽  
Vol 63 (6) ◽  
pp. 1947-1957
Author(s):  
Alexandra Hollo ◽  
Johanna L. Staubitz ◽  
Jason C. Chow
Keyword(s):  
Special Education Teachers ◽  
Generalizability Theory ◽  
Child Outcomes ◽  
Elementary Classrooms ◽  
Teacher Talk ◽  
Group Instruction ◽  
Data Set ◽  
School Year ◽  
Minimum Number ◽  
Representative Samples

Purpose Although sampling teachers' child-directed speech in school settings is needed to understand the influence of linguistic input on child outcomes, empirical guidance for measurement procedures needed to obtain representative samples is lacking. To optimize resources needed to transcribe, code, and analyze classroom samples, this exploratory study assessed the minimum number and duration of samples needed for a reliable analysis of conventional and researcher-developed measures of teacher talk in elementary classrooms. Method This study applied fully crossed, Person (teacher) × Session (samples obtained on 3 separate occasions) generalizability studies to analyze an extant data set of three 10-min language samples provided by 28 general and special education teachers recorded during large-group instruction across the school year. Subsequently, a series of decision studies estimated of the number and duration of sessions needed to obtain the criterion g coefficient ( g > .70). Results The most stable variables were total number of words and mazes, requiring only a single 10-min sample, two 6-min samples, or three 3-min samples to reach criterion. No measured variables related to content or complexity were adequately stable regardless of number and duration of samples. Conclusions Generalizability studies confirmed that a large proportion of variance was attributable to individuals rather than the sampling occasion when analyzing the amount and fluency of spontaneous teacher talk. In general, conventionally reported outcomes were more stable than researcher-developed codes, which suggests some categories of teacher talk are more context dependent than others and thus require more intensive data collection to measure reliably.

RGB Frequency Based Image Steganography

2020 ◽  
pp. 549-553
Author(s):  
Himanshu Kumar ◽  
Nitesh Kumar
Keyword(s):  
Image Steganography ◽  
Minimum Number

In this paper, we introduced a new RGB technique for image steganography. In this technique we introduced the idea of storing a different number of bits per channel (R, G or B) of a pixel based on the frequency of color values of pixel. The higher color frequency retains the maximum number of bits and lower color frequency stores the minimum number of bits.

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