scholarly journals Application of eDNA Metabarcoding for Detecting Anura on a Tropical Island

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 440
Author(s):  
Wenhao Li ◽  
Tianjian Song ◽  
Xianglei Hou ◽  
Mingshuo Qin ◽  
Chunxia Xu ◽  
...  
Keyword(s):  
Large Scale ◽  
Sampling Methods ◽  
Hainan Island ◽  
Nondestructive Method ◽  
Traditional Methods ◽  
Tropical Island ◽  
Anuran Species ◽  
Tropical Environments ◽  
Local Patterns

As anuran biodiversity quickly declines, it is important to understand local patterns of anuran occurrence. However, the limitations of traditional sampling methods make anuran biodiversity surveys inadequate. Tropical environments are rich in anuran species, which makes biodiversity measurements more difficult. Therefore, it is important to develop a rapid, inexpensive and nondestructive method to measure anuran biodiversity in tropical environments. We used eDNA metabarcoding to measure anuran diversity at 288 sites in 18 regions of Hainan Island. We also used traditional methods and compared the results with those obtained through the eDNA metabarcoding methods. We detected 9 anuran species by traditional sampling methods. We produced 626 million reads by eDNA metabarcoding and assigned them to 15 anuran species. Therefore, eDNA metabarcoding can be used for rapid and large-scale anuran biodiversity surveys.

Nitrogen from the atmosphere to the crop

1983 ◽  
Vol 12 (2) ◽  
pp. 90-97 ◽  
Author(s):  
P. P. King
Keyword(s):  
Large Scale ◽  
Crop Plants ◽  
Intensive Agriculture ◽  
Nitrogen Fixing ◽  
Biological Fixation ◽  
Traditional Methods ◽  
The Cost ◽  
Practical Implications

During the middle decades of this century large-scale intensive agriculture relied heavily on the availability of cheap synthetic nitrogenous fertilisers. Little attention then had to be paid to the cost of the energy involved in the manufacture and use of fertilisers, but in recent years this factor has become of major importance. This article reviews the practical implications of the energetics of chemical and biological fixation of nitrogen and the utilisation of nitrogen by various crop plants. It reaches a number of interesting conclusions, including one that even if biotechnology made nitrogen-fixing cereals available, they would not necessarily be competitive with normal cereals produced by traditional methods. This is, however, not necessarily true of grass.

scholarly journals Remote Sensing of Vegetation Recovery in Grasslands after the 1988 Yellowstone Fires in Yellowstone National Park

1990 ◽  
Vol 14 ◽  
pp. 151-153
Author(s):  
Evelyn Merrill ◽  
Cathy Wilson ◽  
Ronald Marrs
Keyword(s):  
Remote Sensing ◽  
Spectral Data ◽  
Satellite Imagery ◽  
Yellowstone National Park ◽  
National Park ◽  
Large Scale ◽  
Vegetation Recovery ◽  
Electromagnetic Spectrum ◽  
Traditional Methods ◽  
Vegetative Biomass

Traditional methods for measurement of vegetative biomass can be time-consuming and labor­intensive, especially across large areas. Yet such estimates are necessary to investigate the effects of large scale disturbances on ecosystem components and processes. One alternative to traditional methods for monitoring rangeland vegetation is to use satellite imagery. Because foliage of plants differentially absorbs and reflects energy within the electromagnetic spectrum, remote sensing of spectral data can be used to quantify the amount of green vegetative biomass present in an area (Tucker and Sellers 1986).

Understanding the effectiveness of measures aiming to stabilize urban gullies in Congolese cities: a systematic analysis based on field surveys

2021 ◽  
Author(s):  
Eric Lutete Landu ◽  
Guy Ilombe Mawe ◽  
Charles Bielders ◽  
Fils Makanzu Imwangana ◽  
Olivier Dewitte ◽  
...  
Keyword(s):  
Large Scale ◽  
Clayey Soil ◽  
Waste Material ◽  
Control Measures ◽  
Household Waste ◽  
Small Scale ◽  
Systematic Analysis ◽  
Tropical Environments ◽  
Retention Ponds ◽  
Local Initiatives

<p>Many cities of the D.R. Congo are strongly affected by urban mega gullies. There are currently hundreds of such gullies in Kinshasa, Kikwit and Bukavu, representing a cumulative length of >200 km. Many of these gullies (typically tens of meters wide and deep) continue to expand, causing major damage to houses and other infrastructure and often claim human casualties. To mitigate these impacts, numerous measures are being implemented. The type and scale of these measures varies widely: from large structural measures like retention ponds to local initiatives of stabilizing gully heads with waste material. Nonetheless, earlier work indicates that an estimated 50% of the existing urban gullies continue to expand, despite the implementation of such measures. As such, we currently have very limited insight into the effectiveness of these measures and the overall best strategies to prevent and mitigate urban gullies. One reason for this is that most initiatives to stabilize urban gullies happen on a rather isolated basis and are rarely evaluated afterwards.</p><p>This work aims to improve our understanding of this issue. For this, we constructed a large inventory of measures implemented to stabilize urban gullies in Kinshasa, Kikwit and Bukavu and statistically confronted these measures with observed vegetation recovery and long-term gully expansion rates (derived from high-resolution imagery over a period of >14 years). Our preliminary results (based on a dataset of > 900 urban gullies) shows that the most commonly applied measures are revegetation and reinforcement of gully heads with sandbags or household waste material (implemented in around 65% of the cases). Retention ponds in streets and infiltration pits on house parcels are also frequently implemented (around 25% of the cases). Overall, techniques relying on vegetation are used relatively more frequently in regions with clayey soil, while techniques involving digging (e.g. infiltration pits) and topographic remodeling (e.g. gully reshaping by creation of terraces) are used mainly in sandy or sandy-clay areas. Surprisingly, small-scale local initiatives, such as stabilizing gully heads with household waste, often appear to have a higher effectivity than some large-scale civil engineering initiatives. However, such small-scale initiatives can come with important additional impacts (e.g. sanitation concerns). More research is needed to confirm these findings. Furthermore, the stability of gullies seems to be strongly linked to the degree of vegetation cover near the gully head. Nonetheless, it is not always clear if vegetation is the cause or the result of this stability. Overall, this study provides one of the first large scale assessments of the effectiveness of gully control measures in urban tropical environments. With this study, we hope to contribute to a better prevention and mitigation of this problem that affects many cities of the tropical Global South.</p>

Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Puerto Rico ◽  
Freshwater Fish ◽  
Water Use ◽  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Physical Habitat ◽  
Resource Exploitation ◽  
Ecological Processes ◽  
Tropical Island

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

scholarly journals An Approach of Identifying and Extracting Urban Commercial Areas Using the Nighttime Lights Satellite Imagery

2020 ◽  
Vol 12 (6) ◽  
pp. 1029
Author(s):  
Xuzhe Duan ◽  
Qingwu Hu ◽  
Pengcheng Zhao ◽  
Shaohua Wang ◽  
Mingyao Ai
Keyword(s):  
Satellite Imagery ◽  
Spatial Data ◽  
Large Scale ◽  
Weather Conditions ◽  
Spatial Data Analysis ◽  
Vegetation Coverage ◽  
Economic Activities ◽  
Traditional Methods ◽  
Detection Model ◽  
Nighttime Lights

Urban commercial areas can reflect the spatial distribution of business activities. However, the scope of urban commercial areas cannot be easily detected by traditional methods because of difficulties in data collection. Considering the positive correlation between business scale and nighttime lighting, this paper proposes a method of urban commercial areas detection based on nighttime lights satellite imagery. First, an imagery preprocess model is proposed to correct imageries and improve efficiency of cluster analysis. Then, an exploratory spatial data analysis and hotspots clustering method is employed to detect commercial areas by geographic distribution metric with urban commercial hotspots. Furthermore, four imageries of Wuhan City and Shenyang City are selected as an example for urban commercial areas detection experiments. Finally, a comparison is made to find out the time and space factors that affect the detection results of the commercial areas. By comparing the results with the existing map data, we are convinced that the nighttime lights satellite imagery can effectively detect the urban commercial areas. The time of image acquisition and the vegetation coverage in the area are two important factors affecting the detection effect. Harsh weather conditions and high vegetation coverage are conducive to the effective implementation of this method. This approach can be integrated with traditional methods to form a fast commercial areas detection model, which can then play a role in large-scale socio-economic surveys and dynamic detection of commercial areas evolution. Hence, a conclusion can be reached that this study provides a new method for the perception of urban socio-economic activities.

Data “big” and “small” – Examples from the Australian lexical database

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Claire Bowern
Keyword(s):  
Big Data ◽  
Large Scale ◽  
Qualitative Data ◽  
Language Change ◽  
First Century ◽  
Lexical Database ◽  
Traditional Methods ◽  
New Methods ◽  
Statistical Approaches ◽  
Insight Into

AbstractThe twenty-first Century has been billed the era of “big data”, and linguists are participating in this trend. We are seeing an increased reliance on statistical and quantitative arguments in most fields of linguistics, including the oldest parts of the field, such as the study of language change. The increased use of statistical methods changes the types of questions we can ask of our data, as well as how we evaluate the answers. But this all has the prerequisite of certain types of data, coded in certain ways. We cannot make powerful statistical arguments from the qualitative data that historical linguists are used to working with. In this paper I survey a few types of work based on a lexical database of Pama-Nyungan languages, the largest family in Aboriginal Australia. I highlight the flexibility with which large-scale databases can be deployed, especially when combined with traditional methods. “Big” data may require new methods, but the combination of statistical approaches and traditional methods is necessary for us to gain new insight into old problems.

Fine-scale habitat change in a marine reserve, mapped using radio-acoustically positioned video transects

2004 ◽  
Vol 55 (3) ◽  
pp. 257 ◽  
Author(s):  
D. M. Parsons ◽  
N. T. Shears ◽  
R. C. Babcock ◽  
T. R. Haggitt
Keyword(s):  
Information System ◽  
Trophic Cascade ◽  
Large Scale ◽  
Sampling Methods ◽  
Marine Reserve ◽  
Kelp Forest ◽  
Habitat Change ◽  
Fine Scale ◽  
Video Footage ◽  
Total Disappearance

Large-scale changes in subtidal reef habitats have occurred within the Leigh Marine Reserve (New Zealand) since its establishment in 1976. To determine the extent of habitat change within Goat Island Bay, video transects positioned by a radio acoustic positioning telemetry (RAPT) system were used to map habitats within a Geographic Information System (GIS) framework. This map was compared to a map of the same area constructed 22 years earlier in 1978. Visual categorisation of habitats was consistent with the quantification of habitat-forming species within quadrats, justifying the creation of a map based on visually interpreted video footage. Furthermore, the large-scale changes in habitats were consistent with smaller-scale changes in community structure identified at permanent sites located in the study area. The most obvious changes were the total disappearance of ‘urchin barrens’ across all depths and the recovery of kelp forest in water <8 m, caused by a trophic cascade related to predator recovery. In water > 12 m, the extent of kelp forest and sponge flats was found to decrease by 25 and 33%, respectively, while turfing algal habitat had increased by 50%. This increase in turfing algal habitat had not been previously documented due to the spatial scale of traditional sampling methods.

scholarly journals Anurans from the “Restinga” of Parque Natural Municipal de Grumari, state of Rio de Janeiro, southeastern Brazil

Check List ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 1267 ◽  
Author(s):  
Felipe Bottona da Silva Telles ◽  
Vanderlaine Amaral Menezes ◽  
Thiago Maia-Carneiro ◽  
Thiago Arnt Dorigo ◽  
Gisele Regina Winck ◽  
...  
Keyword(s):  
Endemic Species ◽  
Rio De Janeiro ◽  
Sampling Methods ◽  
Southeastern Brazil ◽  
Active Sampling ◽  
Amphibian Species ◽  
Anuran Amphibians ◽  
Anuran Species

We present a list of the anuran amphibians from “restinga” of Grumari, part of the Parque Natural Municipal de Grumari (PNMG), Rio de Janeiro municipality, state of Rio de Janeiro, southeastern Brazil. This study was carried out from May 2009 to December 2010 using two active sampling methods: quadrant plots and acoustic/visual transects. We recorded 22 anuran species distributed in six families: Bufonidae (1 species), Craugastoridae (1), Hylidae (14), Leptodactylidae (3), Microhylidae (2) and Strabomantidae (1). The presence of endangered and endemic species evidence Grumari’s importance as an area for conservation of the “restinga” habitat remnants in Rio de Janeiro. Grumari is also one of the richest known areas in terms of amphibian species among the “restinga” areas studied to date in Brazil, second only to Mata de São João, Bahia.

scholarly journals Detecting 2020 Coral Bleaching Event in the Northwest Hainan Island Using CoralTemp SST and Sentinel-2B MSI Imagery

2021 ◽  
Vol 13 (23) ◽  
pp. 4948
Author(s):  
Bailu Liu ◽  
Lei Guan ◽  
Hong Chen
Keyword(s):  
Coral Bleaching ◽  
Large Scale ◽  
Global Climate ◽  
Hainan Island ◽  
Threshold Value ◽  
Bleaching Event ◽  
Wide Range ◽  
Coral Reef Ecosystems ◽  
The Difference ◽  
Difference Images

In recent years, coral reef ecosystems have been affected by global climate change and human factors, resulting in frequent coral bleaching events. A severe coral bleaching event occurred in the northwest of Hainan Island, South China Sea, in 2020. In this study, we used the CoralTemp sea surface temperature (SST) and Sentinel-2B imagery to detect the coral bleaching event. From 31 May to 3 October, the average SST of the study area was 31.01 °C, which is higher than the local bleaching warning threshold value of 30.33 °C. In the difference images of 26 July and 4 September, a wide range of coral bleaching was found. According to the temporal variation in single band reflectance, the development process of bleaching is consistent with the changes in coral bleaching thermal alerts. The results show that the thermal stress level is an effective parameter for early warning of large-scale coral bleaching. High-resolution difference images can be used to detect the extent of coral bleaching. The combination of the two methods can provide better support for coral protection and research.

scholarly journals Is There a Faction in This List?

2020 ◽  
Vol 4 (2) ◽  
pp. 347-389
Author(s):  
Hilde De Weerdt ◽  
Brent Ho ◽  
Allon Wagner ◽  
Jiyan Qiao ◽  
Mingkin Chu
Keyword(s):  
Network Analysis ◽  
Twelfth Century ◽  
Song Dynasty ◽  
Large Scale ◽  
Sampling Methods ◽  
Large Scale Network ◽  
Scale Network ◽  
Network Metrics ◽  
The Relationship

AbstractThis article has two main objectives. First, we aim to revisit debates about the structure of Song Dynasty faction lists and the relationship between eleventh- and twelfth century factional politics on the basis of a large-scale network analysis of co-occurrence ties reported in the prose collections of those contemporary to the events. Second, we aim to innovate methodologically by developing a series of approaches to compare historical networks of different sizes with regard to overall network metrics as well as the significance of particular attributes such as native and workplace in their makeup. The probabilistic and sampling methods developed here should be applicable for various kinds of historical network analysis. The corresponding data can be found here: https://doi.org/10.17026/dans-xtf-z3au.

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