scholarly journals Temporal variation in the population of bulbuls (Family Pycnonotidae) in lower montane forest, Northern Thailand

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Yuwadee Ponpithuk ◽  
Supalak Siri ◽  
Mongkol Safoowong ◽  
Warong Suksavate ◽  
Dokrak Marod ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Temporal Variations ◽  
Montane Forest ◽  
Average Density ◽  
Permanent Plot ◽  
Bird Conservation ◽  
Northern Thailand ◽  
Forest Gaps ◽  
Population Decrease ◽  
Individual Bird

Abstract. Ponpituk Y, Siri S, Safoowong M, Suksavate W, Marod D, Duengkae P. 2020. Temporal variation in the population of bulbuls (Family Pycnonotidae) in lower montane forest, Northern Thailand. Biodiversitas 21: 3644-3649. Temporal variations in the population of bulbuls (Family Pycnonotidae) were studied over the course of four years in a 16-ha lower montane permanent plot, Northern Thailand. This study aimed to determine the relationship of the temporal variation of forest gaps with the population size of the bulbul, which plays a crucial role in seed dispersal and insect control in tropical forest ecosystems. This long-term monitoring study in a permanent plot was conducted monthly from January 2016 through October 2019. Data were collected using the mist-netting method for the capture-recapture protocol with individual bird banding. A total of 33,120 traps hour for 46 months,180 traps hour per day and 720 traps hour per month were recorded. The banding of a total of 94 individual bulbuls resulted in their classification into 5 species, consisting of Puff-throated Bulbul (Alophoixus pallidus), Mountain Bulbul (Ixos mcclellandii), Black-crested Bulbul (Pycnonotus flaviventris), Ashy Bulbul (Hemixos flavala) and Flavescent Bulbul (Iole virescens). The annual average density of bulbul for four years tended to decrease, but the difference was not significant. The highest average population occurred in 2016 and the lowest in 2018 with the changes being attributable to forest gap. Over time, monthly detection of bulbuls decreased gradually under closed canopy conditions, while in forest gaps, bird detection remained constant. As gap conditions so did detection probabilities. Our findings suggest that natural forest gaps can play an essential role as a temporal inhibitor to the rapid bird population decrease in the lower montane forest. This study will be useful for bird conservation and in balancing ecosystems for sustainability and providing interest in conservation initiatives requiring spatially explicit estimates of density.

Temporal variations of atmospheric ammonia (NH3) derived from over a decade of IASI satellite measurements

2021 ◽  
Author(s):  
Martin Van Damme ◽  
Lieven Clarisse ◽  
Bruno Franco ◽  
Mark A Sutton ◽  
Jan Willem Erisman ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
The Netherlands ◽  
Temporal Variation ◽  
Temporal Variations ◽  
Meteorological Conditions ◽  
Satellite Measurements ◽  
Atmospheric Sounding ◽  
National Trends ◽  
The Impact

<p>The Infrared Atmospheric Sounding Interferometer (IASI) mission consists of a suite of three infrared sounders providing today over 13 years of consistent global measurements (from end of 2007 up to now). In this work we use the recently developed version 3 of the IASI NH<sub>3</sub> dataset to derive global, regional and national trends from 2008 to 2018. Reported national trends are analysed in the light of changing anthropogenic and pyrogenic NH<sub>3</sub> emissions, meteorological conditions and the impact of sulphur and nitrogen oxides emissions. A case study is dedicated to the Netherlands. Temporal variation on shorter timescales will also be investigated.</p>

scholarly journals Identification of hydrological model parameter variation using ensemble Kalman filter

2016 ◽  
Vol 20 (12) ◽  
pp. 4949-4961 ◽  
Author(s):  
Chao Deng ◽  
Pan Liu ◽  
Shenglian Guo ◽  
Zejun Li ◽  
Dingbao Wang
Keyword(s):  
Kalman Filter ◽  
Temporal Variation ◽  
Ensemble Kalman Filter ◽  
Water Conservation ◽  
Hydrological Model ◽  
Anthropogenic Activities ◽  
Temporal Variations ◽  
Balance Model ◽  
Model Parameters ◽  
Water Storage Capacity

Abstract. Hydrological model parameters play an important role in the ability of model prediction. In a stationary context, parameters of hydrological models are treated as constants; however, model parameters may vary with time under climate change and anthropogenic activities. The technique of ensemble Kalman filter (EnKF) is proposed to identify the temporal variation of parameters for a two-parameter monthly water balance model (TWBM) by assimilating the runoff observations. Through a synthetic experiment, the proposed method is evaluated with time-invariant (i.e., constant) parameters and different types of parameter variations, including trend, abrupt change and periodicity. Various levels of observation uncertainty are designed to examine the performance of the EnKF. The results show that the EnKF can successfully capture the temporal variations of the model parameters. The application to the Wudinghe basin shows that the water storage capacity (SC) of the TWBM model has an apparent increasing trend during the period from 1958 to 2000. The identified temporal variation of SC is explained by land use and land cover changes due to soil and water conservation measures. In contrast, the application to the Tongtianhe basin shows that the estimated SC has no significant variation during the simulation period of 1982–2013, corresponding to the relatively stationary catchment properties. The evapotranspiration parameter (C) has temporal variations while no obvious change patterns exist. The proposed method provides an effective tool for quantifying the temporal variations of the model parameters, thereby improving the accuracy and reliability of model simulations and forecasts.

scholarly journals Short-term variation in near-highway air pollutant gradients on a winter morning

2010 ◽  
Vol 10 (17) ◽  
pp. 8341-8352 ◽  
Author(s):  
J. L. Durant ◽  
C. A. Ash ◽  
E. C. Wood ◽  
S. C. Herndon ◽  
J. T. Jayne ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Temporal Variation ◽  
Traffic Flow ◽  
Organic Compounds ◽  
Temporal Variations ◽  
Surface Boundary ◽  
Short Term ◽  
Surface Boundary Layer ◽  
Near Highway

Abstract. Quantification of exposure to traffic-related air pollutants near highways is hampered by incomplete knowledge of the scales of temporal variation of pollutant gradients. The goal of this study was to characterize short-term temporal variation of vehicular pollutant gradients within 200–400 m of a major highway (>150 000 vehicles/d). Monitoring was done near Interstate 93 in Somerville (Massachusetts) from 06:00 to 11:00 on 16 January 2008 using a mobile monitoring platform equipped with instruments that measured ultrafine and fine particles (6–1000 nm, particle number concentration (PNC)); particle-phase (>30 nm) NO3−, SO42−, and organic compounds; volatile organic compounds (VOCs); and CO2, NO, NO2, and O3. We observed rapid changes in pollutant gradients due to variations in highway traffic flow rate, wind speed, and surface boundary layer height. Before sunrise and peak traffic flow rates, downwind concentrations of particles, CO2, NO, and NO2 were highest within 100–250 m of the highway. After sunrise pollutant levels declined sharply (e.g., PNC and NO were more than halved) and the gradients became less pronounced as wind speed increased and the surface boundary layer rose allowing mixing with cleaner air aloft. The levels of aromatic VOCs and NO3−, SO42− and organic aerosols were generally low throughout the morning, and their spatial and temporal variations were less pronounced compared to PNC and NO. O3 levels increased throughout the morning due to mixing with O3-enriched air aloft and were generally lowest near the highway reflecting reaction with NO. There was little if any evolution in the size distribution of 6–225 nm particles with distance from the highway. These results suggest that to improve the accuracy of exposure estimates to near-highway pollutants, short-term (e.g., hourly) temporal variations in pollutant gradients must be measured to reflect changes in traffic patterns and local meteorology.

Large variations in composition and spatial distribution of epiphyte biomass on large trees in a tropical montane forest of northern Thailand

Plant Ecology ◽  
2016 ◽  
Vol 217 (9) ◽  
pp. 1157-1169 ◽  
Author(s):  
Akira Nakanishi ◽  
Witchaphart Sungpalee ◽  
Kriangsak Sri-ngernyuang ◽  
Mamoru Kanzaki
Keyword(s):  
Spatial Distribution ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Northern Thailand ◽  
Large Trees

Spatial and Temporal Variations of Atmospheric PM10 and Air Pollutants Concentration in Upper Northern Thailand During 2006–2016

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
Radshadaporn Janta ◽  
Kazuhiko Sekiguchi ◽  
Ryosuke Yamaguchi ◽  
Khajornsak Sopajaree ◽  
Bandhita Plubin ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Northern Thailand

scholarly journals Spatial and temporal variation in pH, alkalinity and conductivity in surface runoff and groundwater for the Upper River Severn catchment

1997 ◽  
Vol 1 (3) ◽  
pp. 697-715 ◽  
Author(s):  
T. Hill ◽  
C. Neal
Keyword(s):  
Temporal Variation ◽  
Ground Water ◽  
Field Measurements ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
Flow Conditions ◽  
Land Usage ◽  
Load Analysis ◽  
Stream Waters ◽  
Upland Catchments

Abstract. Measurements of pH, alkalinity and electrical conductivity are used to examine the extent of the spatial and temporal variation in stream and ground water chemistry for the Upper Severn catchment, Plynlimon. Wide temporal variations in stream waters broadly reflect flow conditions and complex soil and ground water interactions but not soil type, land usage or geology. The results have major implications for the use of critical load analysis and the development and application of models in upland catchments. They point to the value of field measurements for assessing the environmental management of upland catchments, rather than the present use of over simplistic or inappropriate models.

Secondary forest succession after the cessation of swidden cultivation in the montane forest area in Northern Thailand

2008 ◽  
Vol 255 (5-6) ◽  
pp. 1994-2006 ◽  
Author(s):  
Maki Fukushima ◽  
Mamoru Kanzaki ◽  
Masatoshi Hara ◽  
Tatsuhiro Ohkubo ◽  
Pornchai Preechapanya ◽  
...  
Keyword(s):  
Forest Succession ◽  
Secondary Forest ◽  
Montane Forest ◽  
Forest Area ◽  
Swidden Cultivation ◽  
Northern Thailand ◽  
Secondary Forest Succession

scholarly journals Temporal Variation Dominates in Local Carabid Beetle Communities in Korean Mountains

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1019
Author(s):  
Yonghwan Park ◽  
Taewoong Jang ◽  
Jongkuk Kim ◽  
Su-Kyung Kim ◽  
Il-Kwon Kim ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Temporal Variation ◽  
Spatial Scales ◽  
Temporal Variations ◽  
Carabid Beetle ◽  
Spatial And Temporal Variation ◽  
Mountain Range ◽  
Insect Communities ◽  
Local Climate ◽  
Study Sites

Spatial and temporal variation in ecological environments may result in spatial and temporal variation in communities. Temporal studies of biodiversity are essential for forecasting future changes in community structure and ecosystem function. Therefore, determining the mechanisms that drive temporal change in communities remains an important and interesting challenge in ecology. We quantified spatial and temporal variations in carabid beetle communities and site-specific environmental factors for 5 years at nine study sites on three mountains in the Baekdudaegan Mountain Range, Korea. Carabid beetle communities exhibited significant temporal variation, which was larger than spatial variations between and within mountains. Environmental factors mostly varied between sites within mountains. Community variation was only weakly associated with environmental factors at wide scales, i.e., between sites on three mountains, but was strongly associated at narrow spatial scales, i.e., between sites within one mountain. Our results indicate that temporal variation in communities occurs in response to variations in the local climate, and that the patterns of temporal variation differ between mountains. Thus, temporal surveys of insect communities and climates at local scales are important for predicting temporal changes in the communities.

scholarly journals Temporal variation of sandy beach macrofauna at two sites with distinct environmental conditions on Cassino Beach, extreme southern Brazil

2008 ◽  
Vol 56 (4) ◽  
pp. 257-270 ◽  
Author(s):  
Pedro de Sá Rodrigues da Silva ◽  
Luciano Peyrer das Neves ◽  
Carlos Emílio Bemvenuti
Keyword(s):  
Temporal Variation ◽  
Dominant Species ◽  
Sandy Beach ◽  
Temporal Variations ◽  
Sandy Beaches ◽  
Subtidal Zone ◽  
Low Density ◽  
Environmental Condition ◽  
Southern Brazil ◽  
Low Intensity

Temporal variations of the macrofauna of sandy beaches have been related to variations in the beach morphodynamics and also to the population dynamics of dominant species. The aim of this article is to describe the temporal variation of the intertidal macrofauna at two sites with distinct environmental condition on Cassino Beach, extreme southern Brazil. At each site three transect lines 50 m apart were defined perpendicular to the shore line, from which samples were collected monthly in triplicate at 4 intertidal levels (10 m apart) from June 2004 to May 2005. During winter a generally low density was observed, due to the absence of recruitments and to the mud deposition, which occurred just before sampling (in April 2004), and to low intensity stranding events. Spring witnessed a population explosion of Scolelepis gaucha, a migration of Mesodesma mactroides adults from the subtidal zone, and a strong stranding event. In the summer, recruitment of M. mactroides, Donax hanleyanus and Emerita brasiliensis was observed. Fall was characterized by low densities, except for D. hanleyanus recruitment. The macrofauna at both sites showed a striking seasonal variation in density and diversity, perhaps attributable to the recruitment of numerically dominant species and physical disturbances (stranding and mud deposition).

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