scholarly journals A Comparison of Four Distance Sampling Techniques in South Texas Live Oak Mottes

1975 ◽  
Vol 28 (2) ◽  
pp. 142 ◽  
Author(s):  
Samuel L. Beasom ◽  
Harry H. Haucke
Keyword(s):  
Distance Sampling ◽  
South Texas ◽  
Sampling Techniques ◽  
Live Oak

Relations among hydrocarbon reservoirs, epigenetic sulfidization, and rock magnetization: Examples from the south Texas coastal plain

Geophysics ◽  
1991 ◽  
Vol 56 (6) ◽  
pp. 748-757 ◽  
Author(s):  
M. B. Goldhaber ◽  
R. L. Reynolds
Keyword(s):  
Iron Sulfide ◽  
Petroleum Reservoirs ◽  
South Texas ◽  
Near Surface ◽  
Shallow Subsurface ◽  
Reservoir Rocks ◽  
Sulfate Reducing ◽  
Organic Constituents ◽  
Live Oak ◽  
Reducing Bacteria

This paper focuses on the association between concentrations of iron disulfide [Formula: see text] minerals in the shallow subsurface and underlying hydrocarbon accumulations. Such [Formula: see text] concentrations are the result of migration of either [Formula: see text] or organic constituents from the underlying hydrocarbons. The [Formula: see text] from reservoirs is produced inorganically from sulfate in the reservoir rocks at high temperature (>90°C) and migrates to shallower beds to react inorganically with iron to form [Formula: see text]. Organic constituents from reservoirs, in contrast, provide nourishment for sulfate reducing bacteria in shallow relatively cool (<90°C) beds. Sandstone in the Ray Point uranium district in Live Oak County, Texas contains abundant [Formula: see text] which formed both from deep‐seated [Formula: see text] and from [Formula: see text] produced in the shallow subsurface by bacteria that utilized organic materials from depth. Deep petroleum reservoirs were physically connected to near‐surface (<100 m) beds containing epigenetic [Formula: see text] by the Oakville fault. Epigenetic iron sulfide formation occurred in at least four episodes over at least five million years. Evidence from the Ray Point district and elsewhere in Texas illustrates that sulfidization reactions have destroyed magnetic iron‐titanium oxide minerals in the vicinity of major growth faults, resulting in a systematic decrease in magnetic susceptibility and magnitude of remanent magnetization in the vicinity of such faults. Growth faults which tap hydrocarbon deposits may be detectable using aeromagnetic methods.

Application of distance sampling techniques for diving ducks on Lake St. Clair and western Lake Erie

2014 ◽  
Vol 40 (2) ◽  
pp. 274-280 ◽  
Author(s):  
Brendan T. Shirkey ◽  
David R. Luukkonen ◽  
Scott R. Winterstein
Keyword(s):  
Lake Erie ◽  
Distance Sampling ◽  
Sampling Techniques ◽  
Diving Ducks ◽  
Western Lake ◽  
Western Lake Erie

Control of Live Oak in South Texas

1969 ◽  
Vol 22 (5) ◽  
pp. 315 ◽  
Author(s):  
R. W. Bovey ◽  
S. K. Lehman ◽  
H. L. Morton ◽  
J. R. Baur
Keyword(s):  
South Texas ◽  
Live Oak

scholarly journals ESTIMASI KEPADATAN ULAT API MELALUI METODE SAMPLING JARAK

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Cukri Rahmi Niani
Keyword(s):  
Oil Palm ◽  
Sampling Method ◽  
Distance Sampling ◽  
Sampling Techniques ◽  
Sampling Distance ◽  
Setora Nitens

Many types of pests which is found in oil palm plantations such as rats, bees and the caterpillars. Caterpillar and the bagworm, including a caterpillar eaters leaves oil palm plantations. This Research focuses on a caterpillar type Setora nitens at oil palm plantations Karya Tanah Subur in West Aceh. Many ways that has been done to overcome pests caterpillar in oil palm plantations from early monitoring and extermination caterpillar. To know the density caterpillar can be done by counting directly individual caterpillar or with other methods that in this research, the density caterpillar in the estimation through distance sampling techniques. Distance sampling is one of the methods used to estimate the density and the spread population. The sampling distance, a series point or lines are placed randomly on the districts census and measured the distance between individuals who were detected in handcuffs or this point. Ordered Distance, Point Quarter and Variable Area Transect the distance sampling method that used in the research. Based on the explanation, an extensive microinsurance is focused on the estimation density caterpillar using the distance sampling methods.Keywords: Setora nitens, Distance Sampling, Order Distance, Point Quarter, VariableArea Transect.

Estimates of Southern Rockhopper and Macaroni Penguin Numbers at the Ildefonso and Diego Ramírez Archipelagos, Chile, Using Quadrat and Distance-sampling Techniques

Waterbirds ◽  
2007 ◽  
Vol 30 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Roger Kirkwood ◽  
Kieran Lawton ◽  
Carlos Moreno ◽  
Jose Valencia ◽  
Roberto Schlatter ◽  
...  
Keyword(s):  
Distance Sampling ◽  
Sampling Techniques ◽  
Macaroni Penguin

Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris

2003 ◽  
Vol 33 (8) ◽  
pp. 1564-1579 ◽  
Author(s):  
M S Williams ◽  
J H Gove
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Distance Sampling ◽  
Sampling Technique ◽  
Sampling Techniques ◽  
New Methods ◽  
Unequal Probability ◽  
Perpendicular Distance ◽  
The Difference ◽  
Primary Advantage

Coarse woody debris (CWD) plays an important role in many forest ecosystem processes. In recent years, a number of new methods have been proposed to sample CWD. These methods select individual logs into the sample using some form of unequal probability sampling. One concern with most of these methods is the difficulty in estimating the volume of each log. A new method of sampling CWD that addresses this issue is proposed. This method samples each log with probability proportional to the volume of each piece of CWD. While this method generally has a smaller variance than the existing methods, the primary advantage is that a design-unbiased estimator of CWD volume is achieved without ever actually measuring the volume of any logs. This method, referred to as perpendicular distance sampling (PDS), is compared with three existing sampling techniques for CWD using a simulation study on a series of artificial populations. In every case, the variance of the PDS estimator of CWD volume was smaller than the variance of the competing methods, but the difference in the variance was not large between PDS and two of the competing methods. When estimating the number of pieces of CWD, the variance of the PDS estimator was one of the largest amongst the tested methods. An equally important result is that the variant of line intersect sampling used in this study, where the orientation of the line is the same at all sample points, performed poorly in every situation. This and other problems suggest that the suitability of this sampling technique for estimating CWD is questionable.

Abundance and distribution of the harbour porpoise (Phocoena phocoena) on the north coast of Anglesey, Wales, UK

2008 ◽  
Vol 89 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Richard Shucksmith ◽  
Nia H. Jones ◽  
George W. Stoyle ◽  
Andrew Davies ◽  
Emily F. Dicks
Keyword(s):  
Distance Sampling ◽  
Harbour Porpoise ◽  
North Coast ◽  
Sampling Techniques ◽  
Phocoena Phocoena ◽  
Ecological Data ◽  
Robust Estimate ◽  
The North ◽  
North Wales ◽  
Abundance And Distribution

A three year study was undertaken during 2002 to 2004 from May to September to estimate abundance and density of harbour porpoises on the north coast of Anglesey, Wales, UK. There were no ecological data regarding the harbour porpoises in Anglesey waters so the ability to influence conservation measures was highly constrained.Boat based transects using distance sampling techniques were applied so a robust estimate of density and abundance could be attained. The study area consisted of a block approximately 489 km2 extending from the east of Point Lynas to the west of South Stack on north coast of Anglesey. The study area was divided into 5 blocks consisting of 31 perpendicular transect lines to the shore. Each of the transect lines were surveyed 1–5 times by the end of the three year study.Based on the assumption that g(0) = 1 the density of harbour porpoises for the 489 km2 study site was estimated to be 0.630 individuals/km2 (CV = 0.20) and the abundance is estimated to be 309 individuals (CV = 0.20). Heterogeneity in density and abundance was observed across the 5 blocks which showed Point Lynas and South Stack to have the highest densities. This distribution was closely associated to fine-scale oceanographic features which cause prey to be concentrated and may facilitate foraging for harbour porpoises. The study showed that Anglesey provides coastal habitats for the harbour porpoise and was the first study of this kind in North Wales, UK.

scholarly journals New estimates of orangutan density in Sungai Palin watershed, Kapuas Hulu, West Kalimantan, Indonesia

Oryx ◽  
2019 ◽  
Vol 54 (6) ◽  
pp. 763-766 ◽  
Author(s):  
Achmad Yanuar ◽  
Jan Fehse ◽  
David Chivers ◽  
Jito Sugardjito
Keyword(s):  
Distance Sampling ◽  
Pongo Pygmaeus ◽  
Critically Endangered ◽  
Sampling Techniques ◽  
West Kalimantan ◽  
Bornean Orangutan ◽  
Peat Swamp ◽  
Pongo Pygmaeus Pygmaeus ◽  
Conservation And Management

AbstractPongo pygmaeus pygmaeus is a subspecies of Bornean orangutan whose distribution is restricted to the northern part of the Kapuas River, West Kalimantan, and is categorized as Critically Endangered. In October 2017 we carried out a survey to estimate orangutan density in the peat-swamp forests of the Sungai Palin watershed, of the upper Kapuas river, Kapuas Hulu, West Kalimantan, Indonesia. Surveys for orangutans in 1991, in nearby Nanga Awen, had indicated the presence of orangutans in the peat-swamp forests of this area. We used distance sampling techniques to estimate orangutan densities from nest observations. We recorded 76 orangutan nests along 4.5 km transects in Sungai Palin in 2017, and 71 orangutan nests were observed along 4.3 km transects in Nanga Awen in 1991, giving densities of 1.29 and 2.62 individuals/km2, respectively. The results of this orangutan survey can be used as a baseline for monitoring of orangutan populations for conservation and management of this watershed landscape.

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