PubAg

Main content area

You searched for: Subject "vegetation cover" Remove constraint Subject: "vegetation cover" Subject models Remove constraint Subject: models Subject vegetation cover Remove constraint Subject: vegetation cover
Start Over

Search

756  Search Results

« Previous | 1 - 20 of 756 |
Number of results to display per page

Search Results

1. Different representations of canopy structure—A large source of uncertainty in global land surface modeling

Author:
Dai, Yongjiu; Yuan, Hua; Xin, Qinchuan; Wang, Dagang; Shangguan, Wei; Zhang, Shupeng; Liu, Shaofeng; Wei, Nan
Source:
Agricultural and forest meteorology 2019 v.269-270 pp. 119-135
ISSN:
0168-1923
Subject:
vegetation cover,   etc   ; absorption; botanical composition; canopy; ecosystems; geometry; land cover; models; shortwave radiation; uncertainty;     Show all 10 Subjects
Abstract:
... Land surface models generally use a “mosaic” approach to represent subgrid variation in canopy structure within a given land cell in two ways: one is based on vegetation cover types (VCT) (e.g., biomes or land cover classes); the other uses plant functional types (PFT)—a further breakdown of VCTs. The two representations largely differ in their representations of vegetation composition and canopy ...
DOI:
10.1016/j.agrformet.2019.02.006

2. Assessing Submerged Vegetation Roughness in Streambed under Clear Water Condition Using Physical Modeling

Author:
Hosna Shafaei,; Amini, Ata; Shirdeli, Azim
Source:
Water resources 2019 v.46 no.3 pp. 377-383
ISSN:
0097-8078
Subject:
vegetation cover,   etc   ; hydraulic flumes; models; rivers; roughness; sediments; shrublands; stream channels; submerged aquatic plants; waterways;     Show all 10 Subjects
Abstract:
... Roughness coefficient, also called Manning’s coefficient, is one of the most important hydraulic parameters in the rivers. This coefficient, in addition to the flow conditions, depends on streambed characteristics such as type and density of vegetation. In this study, a physical model in a flume with 7 m length, 0.25 m width and 0.25 m height was conducted to evaluate the streambed roughness coeff ...
DOI:
10.1134/S0097807819030084

3. Machine learning and multi-sensor based modelling of woody vegetation in the Molopo Area, South Africa

Author:
Ludwig, Marvin; Morgenthal, Theunis; Detsch, Florian; Higginbottom, Thomas P.; Lezama Valdes, Maite; Nauß, Thomas; Meyer, Hanna
Source:
Remote sensing of environment 2019 v.222 pp. 195-203
ISSN:
0034-4257
Subject:
vegetation cover,   etc   ; algorithms; artificial intelligence; databases; geometry; grazing; models; prediction; radar; remote sensing; savannas; South Africa;     Show all 12 Subjects
Abstract:
... Bush encroachment is a highly relevant environmental issue in South African savannas, influencing ecological processes as well as the grazing capacity of the land. However the drivers of bush encroachment are not yet fully revealed which can partly be attributed to the problem that large-scale data of woody vegetation cover are missing. Using a multi-scale and a multi-sensor approach, this study a ...
DOI:
10.1016/j.rse.2018.12.019

4. Disentangling variables that influence growth response of balsam fir regeneration during a spruce budworm outbreak

Author:
Nie, Zhuoyi; MacLean, David A.; Taylor, Anthony R.
Source:
Forest ecology and management 2019 v.433 pp. 13-23
ISSN:
0378-1127
Subject:
vegetation cover,   etc   ; Abies balsamea; Choristoneura fumiferana; canopy; climate; defoliation; ground vegetation; hardwood; models; softwood;     Show all 10 Subjects
Abstract:
... Height increment of balsam fir (Abies balsamea (L.) Mill.) regeneration during a spruce budworm (Choristoneura fumiferana Clem.) outbreak can be affected by a variety of variables including defoliation, ground vegetation competition, canopy openness, the height of regeneration, and stand type. To disentangle how these variables interact to determine regeneration height increment, we sampled 36 plo ...
DOI:
10.1016/j.foreco.2018.10.050

5. Quantifying the spatio-temporal drivers of planned vegetation restoration on ecosystem services at a regional scale

Author:
Liu, Yuanxin; Lü, Yihe; Fu, Bojie; Harris, Paul; Wu, Lianhai
Source:
The Science of the total environment 2019 v.650 pp. 1029-1040
ISSN:
0048-9697
Subject:
vegetation cover,   etc   ; decision making; ecological restoration; ecosystem management; ecosystem services; models; population density; yearbooks; China;     Show all 9 Subjects
Abstract:
... Vegetation restoration often has a significant effect on the supply of an ecosystem service (ES). Assessment of this effect is crucial for informed decision-making in sustainable ecosystem management. In this respect, this study analyses three regulating, two provisioning, and a single cultural ES over a 30-year period (1985 to 2015, with 15 years pre-restoration and 15 years post-restoration) in ...
DOI:
10.1016/j.scitotenv.2018.09.082

6. Using ignorance scores to explore biodiversity recording effort for multiple taxa in the Caatinga

Author:
Correia, Ricardo A.; Ruete, Alejandro; Stropp, Juliana; Malhado, Ana C.M.; dos Santos, Janisson W.; Lessa, Thainá; Alves, José A.; Ladle, Richard J.
Source:
Ecological indicators 2019 v.106 pp. 105539
ISSN:
1470-160X
Subject:
vegetation cover,   etc   ; biodiversity; caatinga; conservation areas; ecoregions; environmental indicators; geographical distribution; human population; models; population density; prioritization; tropical forests; universities;     Show all 13 Subjects
Abstract:
... The availability of quality information about species distributions is clearly central to the development of successful conservation efforts. Digital records of species occurrences are increasingly available and have been used in a number of conservation applications, such as species distribution models and conservation prioritization efforts. However, our knowledge of species distributions is sti ...
DOI:
10.1016/j.ecolind.2019.105539

7. Potential of soil moisture retrieval for tropical peatlands in Indonesia using ALOS-2 L-band full-polarimetric SAR data

Author:
Izumi, Y.; Widodo, J.; Kausarian, H.; Demirci, S.; Takahashi, A.; Razi, P.; Nasucha, M.; Yang, H.; Tetuko S. S., J.
Source:
International journal of remote sensing 2019 v.40 no.15 pp. 5938-5956
ISSN:
1366-5901
Subject:
vegetation cover,   etc   ; land clearing; models; peatlands; polarimetry; remote sensing; soil water; synthetic aperture radar; time domain reflectometry; Indonesia;     Show all 10 Subjects
Abstract:
... In this paper, a soil moisture retrieval from full-polarimetric synthetic aperture radar (SAR) data is investigated for sparsely vegetated soil surfaces. An improved retrieval method adapting the variations in vegetation is proposed by incorporating the generalized volume model into the polarimetric two-scale two-component model (PTSTCM). The feasibility of the method, termed as the adaptive PTSTC ...
DOI:
10.1080/01431161.2019.1584927

8. Remotely sensed albedo allows the identification of two ecosystem states along aridity gradients in Africa

Author:
Zhao, Yanchuang; Wang, Xinyuan; Novillo, Carlos J.; Arrogante‐Funes, Patricia; Vázquez‐Jiménez, René; Berdugo, Miguel; Maestre, Fernando T.
Source:
Land degradation & development 2019 v.30 no.12 pp. 1502-1515
ISSN:
1085-3278
Subject:
vegetation cover,   etc   ; arid lands; climate; climate change; desertification; dry environmental conditions; ecosystems; evapotranspiration; land degradation; models; remote sensing; Africa;     Show all 12 Subjects
Abstract:
... Empirical verification of multiple states in drylands is scarce, impeding the design of indicators to anticipate the onset of desertification. Remote sensing‐derived indicators of ecosystem states are gaining new ground due to the possibilities they bring to be applied inexpensively over large areas. Remotely sensed albedo has been often used to monitor drylands due to its close relationship with ...
DOI:
10.1002/ldr.3338

9. Spruce representation in zonal woodlands may be overestimated when using pollen spectra from peatlands

Author:
Hájková, Petra; Jamrichová, Eva; Wiezik, Maroš; Peterka, Tomáš; Petr, Libor; Singh, Patrícia; Máliš, František; Fajmonová, Zuzana; Hájek, Michal
Source:
Review of palaeobotany and palynology 2019
ISSN:
0034-6667
Subject:
vegetation cover,   etc   ; Fagus; Picea; databases; fossils; landscapes; models; peatlands; pollen; sediments; stomata; trees; woodlands; Carpathian region; Central European region;     Show all 15 Subjects
Abstract:
... The proportion of taxa in a pollen spectrum may not correspond to their proportion in vegetation. Quantitative reconstruction models therefore consider pollen productivities or fall speeds. We argue that azonal presence of spruce, an otherwise zonal tree species, in wetlands may confound the pollen-inferred reconstructions of vegetation cover as well. Based on a large database of vegetation plots ...
DOI:
10.1016/j.revpalbo.2019.104104

10. Soil moisture estimation using two-component decomposition and a hybrid X-Bragg/Fresnel scattering model

Author:
Shi, Hongtao; Yang, Jie; Li, Pingxiang; Zhao, Lingli; Liu, Zhiqu; Zhao, Jinqi; Liu, Wensong
Source:
Journal of hydrology 2019 v.574 pp. 646-659
ISSN:
0022-1694
Subject:
vegetation cover,   etc   ; dielectric properties; models; polarimetry; satellites; soil water; surface roughness; synthetic aperture radar; topographic slope; China; Oklahoma;     Show all 11 Subjects
Abstract:
... Polarimetric synthetic aperture radar (PolSAR), as an advanced active sensor, can penetrate vegetation to detect ground information. The multimode observation data can provide more information to interpret different scattering mechanisms and have great application potential in soil moisture estimation (SME). In this paper, a modified method of soil moisture inversion from PolSAR data based on a tw ...
DOI:
10.1016/j.jhydrol.2019.04.049

11. Estimation of active-passive microwave covariation using SMAP and Sentinel-1 data

Author:
Jagdhuber, Thomas; Baur, Martin; Akbar, Ruzbeh; Das, Narendra N.; Link, Moritz; He, Lian; Entekhabi, Dara
Source:
Remote sensing of environment 2019 v.225 pp. 458-468
ISSN:
0034-4257
Subject:
vegetation cover,   etc   ; microwave radiometers; models; radiometry; remote sensing; soil; spatial data; statistical analysis; synthetic aperture radar; temperature; time series analysis;     Show all 11 Subjects
Abstract:
... Active and passive microwave signals over land co-vary depending on their shared scattering and emission characteristics by soil and vegetation media. Estimates of this covariation can be used beneficially to downscale coarse-resolution brightness temperatures with high-resolution backscatter for enhanced-resolution Earth observations. In this study, a forward model of covariation for vegetated so ...
DOI:
10.1016/j.rse.2019.03.021

12. Validation of the Sentinel Simplified Level 2 Product Prototype Processor (SL2P) for mapping cropland biophysical variables using Sentinel-2/MSI and Landsat-8/OLI data

Author:
Djamai, Najib; Fernandes, Richard; Weiss, Marie; McNairn, Heather; Goïta, Kalifa
Source:
Remote sensing of environment 2019 v.225 pp. 416-430
ISSN:
0034-4257
Subject:
vegetation cover,   etc   ; canopy; cropland; crops; data collection; leaf area index; models; prototypes; remote sensing; time series analysis; uncertainty; water content;     Show all 12 Subjects
Abstract:
... The Simplified Level 2 Product Prototype Processor (SL2P) for estimating Leaf Area index (LAI), fraction of vegetation cover (fCover) and Canopy Water Content (CWC) from Sentinel-2/MSI and Landsat-8/OLI data was validated over an agricultural region. In-situ data collected during the SMAP Validation Experiment 2016 field campaign were used as a reference. SL2P processor performance varied substant ...
DOI:
10.1016/j.rse.2019.03.020

13. Geographically Weighted Negative Binomial Regression Model Predicts Wildfire Occurrence in the Great Xing’an Mountains Better Than Negative Binomial Model

Author:
Su, Zhangwen; Hu, Haiqing; Tigabu, Mulualem; Wang, Guangyu; Zeng, Aicong; Guo, Futao
Source:
Forests 2019 v.10 no.5
ISSN:
1999-4907
Subject:
vegetation cover,   etc   ; boreal forests; fire prevention; humans; models; mountains; prediction; regression analysis; relative humidity; temperature; topography; wildfires; China;     Show all 13 Subjects
Abstract:
... Wildfire is a major disturbance that affects large area globally every year. Thus, a better prediction of the likelihood of wildfire occurrence is essential to develop appropriate fire prevention measures. We applied a global negative Binomial (NB) and a geographically weighted negative Binomial regression (GWNBR) models to determine the relationship between wildfire occurrence and its drivers fac ...
DOI:
10.3390/f10050377

14. Modeling canopy conductance and transpiration from solar-induced chlorophyll fluorescence

Author:
Shan, Nan; Ju, Weimin; Migliavacca, Mirco; Martini, David; Guanter, Luis; Chen, Jingming; Goulas, Yves; Zhang, Yongguang
Source:
Agricultural and forest meteorology 2019 v.268 pp. 189-201
ISSN:
0168-1923
Subject:
vegetation cover,   etc   ; eddy covariance; canopy; energy; stomatal conductance; cropland; models; remote sensing; ecosystems; photosynthesis; chlorophyll; grasslands; stomata; forests;     Show all 14 Subjects
Abstract:
... Vegetation transpiration (T) is the process of plant water loss through the stomata on the leaf surface and plays a key role in the energy and water balance of the land surface, especially with dense vegetation cover. To date, however, estimation of ecosystem-scale T is still rather uncertain mainly due to errors in modeling canopy resistance or conductance. Considering the intrinsic link between ...
DOI:
10.1016/j.agrformet.2019.01.031

15. Variations in soil temperature from 1980 to 2015 in permafrost regions on the Qinghai-Tibetan Plateau based on observed and reanalysis products

Author:
Hu, Guojie; Zhao, Lin; Li, Ren; Wu, Xiaodong; Wu, Tonghua; Xie, Changwei; Zhu, Xiaofan; Su, Youqi
Source:
Geoderma 2019 v.337 pp. 893-905
ISSN:
0016-7061
Subject:
vegetation cover,   etc   ; alpine meadows; autumn; climate change; models; permafrost; soil temperature; spring; steppes; thermal properties; weather forecasting; wetlands; winter; China;     Show all 14 Subjects
Abstract:
... Soil temperature is an important physical variable of soil and plays a key role in controlling the underground hydro-thermal processes in permafrost regions on the Qinghai-Tibetan Plateau (QTP). Daily soil temperatures were observed at five different vegetation cover sites (alpine wet meadow, alpine meadow, alpine steppe, alpine desert steppe and alpine desert) from 2012 to 2015 in permafrost regi ...
DOI:
10.1016/j.geoderma.2018.10.044

16. Do migratory and resident birds differ in their responses to interacting effects of climate, weather and vegetation?

Author:
Lindenmayer, David B.; Lane, Peter; Foster, Claire N.; Westgate, Martin J.; Sato, Chloe; Ikin, Karen; Crane, Mason; Michael, Damian; Florance, Daniel; Scheele, Ben C.
Source:
Diversity & distributions 2019 v.25 no.3 pp. 449-461
ISSN:
1366-9516
Subject:
vegetation cover,   etc   ; birds; climate change; climatic factors; drying; habitats; migratory behavior; models; rain; regrowth; surveys; temperature; woodlands; Australia;     Show all 14 Subjects
Abstract:
... AIM: Knowledge of the individual and collective effects of habitat, weather variability and climate on bird populations is limited, with the result that species vulnerability to the collective impacts of global change is poorly understood. We quantified the effects of interactions between these potential drivers on the occurrence of resident, migratory and nomadic birds in Australian temperate woo ...
DOI:
10.1111/ddi.12874

17. Assessing niche overlap between domestic and threatened wild sheep to identify conservation priority areas

Author:
Bleyhl, Benjamin; Arakelyan, Marine; Askerov, Elshad; Bluhm, Hendrik; Gavashelishvili, Alexander; Ghasabian, Mamikon; Ghoddousi, Arash; Heidelberg, Aurel; Khorozyan, Igor; Malkhasyan, Alexander; Manvelyan, Karen; Masoud, Mohammadreza; Moqanaki, Ehsan M.; Radeloff, Volker C.; Soofi, Mahmood; Weinberg, Paul; Zazanashvili, Nugzar; Kuemmerle, Tobias
Source:
Diversity & distributions 2019 v.25 no.1 pp. 129-141
ISSN:
1366-9516
Subject:
vegetation cover,   etc   ; ancestry; dogs; forage; grazing intensity; habitat preferences; models; mouflon; niches; planning; remote sensing; sheep; Caucasus region;     Show all 13 Subjects
Abstract:
... AIM: Populations of large ungulates are dwindling worldwide. This is especially so for wild sheep, which compete with livestock for forage, are disturbed by shepherds and their dogs, and are exposed to disease transmissions from livestock. Our aim was to assess spatial patterns in realized niche overlap between wild and domestic sheep to better understand where potential competition might arise, a ...
DOI:
10.1111/ddi.12839

18. Do soil-adjusted or standard vegetation indices better predict above ground biomass of semi-arid, saline rangelands in North-East Iran?

Author:
Gholami Baghi, Naghmeh; Oldeland, Jens
Source:
International journal of remote sensing 2019 v.40 no.22 pp. 8223-8235
ISSN:
1366-5901
Subject:
vegetation cover,   etc   ; aboveground biomass; arid lands; models; moderate resolution imaging spectroradiometer; normalized difference vegetation index; prediction; rangelands; regression analysis; remote sensing; satellites; soil; Iran;     Show all 13 Subjects
Abstract:
... Satellite remote sensing has greatly facilitated the assessment of aboveground biomass in rangelands. Soil-adjusted vegetation indices have been developed to provide better predictions of aboveground biomass, especially for dryland regions. Semi-arid rangelands often complicate a remote sensing based assessment of aboveground biomass due to bright reflecting soils combined with sparse vegetation c ...
DOI:
10.1080/01431161.2019.1606958

19. Landscape-level vegetation classification and fractional woody and herbaceous vegetation cover estimation over the dryland ecosystems by unmanned aerial vehicle platform

Author:
Wang, Haozhou; Han, Dong; Mu, Yue; Jiang, Lina; Yao, Xueling; Bai, Yongfei; Lu, Qi; Wang, Feng
Source:
Agricultural and forest meteorology 2019 v.278 pp. 107665
ISSN:
0168-1923
Subject:
vegetation cover,   etc   ; Internet; arid lands; computer software; data collection; decision support systems; ecosystems; image analysis; models; regression analysis; remote sensing; shrubs; support vector machines; trees; unmanned aerial vehicles;     Show all 15 Subjects
Abstract:
... The change of fraction vegetation cover (FVC) is the key ecological index for vegetation dynamics of dryland ecosystem. However, it is difficult to directly map woody vegetation and herbaceous vegetation in the dryland from the satellite images due to the mixture of their distribution at small scale. Emerging UAV remote sensing provides a good opportunity to capture and quantify the distribution o ...
DOI:
10.1016/j.agrformet.2019.107665

20. Dominant control of climate variations over land-use change on net primary productivity under different urbanization intensities in Beijing, China

Author:
Tian, Yuhong; Huang, Weilin; Wu, Xiuchen; Jim, C.Y.; Wang, Xinpan; Liu, Yiqing
Source:
Acta ecologica Sinica 2019 v.39 no.5 pp. 416-424
ISSN:
1872-2032
Subject:
vegetation cover,   etc   ; anthropogenic activities; case studies; climatic factors; environmental impact; forests; land use change; models; net primary productivity; reforestation; remote sensing; spatial data; urbanization; China;     Show all 14 Subjects
Abstract:
... Climate variations and land-use change induced by rapid urbanization can lead to crucial impacts on ecosystem Net Primary Productivity (NPP), especially in regions with intensive human activity. However, the relative contributions of land-use change and climate variations to NPP changes under different urbanization intensities are still a topic of debate. This study reports on a case study in Beij ...
DOI:
10.1016/j.chnaes.2019.07.002