Search results for "VEGETATION"
showing 10 items of 1069 documents
Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia
2009
We examined the regeneration patterns of Pinus sylvestris L. in a natural treed mire in the hemiboreal zone in Latvia. Data on tree stem age and size was collected in 207 fine-scale plots (10 m) and 4 medium-scale plots (400 m). Size structure of living and dead trees was also estimated on transects 180-m and 250-m length and 10-m width. In addition, the vegetation was described in 1-m plots to determine preferred microsites for P. sylvestris establishment. Pinus sylvestris showed continuous regeneration by an inverse J-shaped age and size structure. Pulses of mortality induced by fire were also evident. Regeneration of P. sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free o…
Retrieving and broadcasting near-real-time biophysical parameters from MODIS and SEVIRI receiving stations at the global change unit of the Universit…
2015
We present here the automatic processing chains implemented at the Global Change Unit of the University of Valencia. These allow for a near-real-time retrieval of various biophysical parameters from both Sun-synchronous TERRA/AQUA Moderate Resolution Imaging Spectroradiometer MODIS and geostationary Meteosat Second Generation Spinning Enhanced Visible and Infrared Imager MSG SEVIRI sensors. Retrieved parameters, namely sea and land surface temperatures SST and LST, respectively, normalized difference vegetation index NDVI, and vegetation condition index VCI, are similar for both sensors, and specific approaches have been developed and implemented for near-real-time parameter retrievals: htt…
Fine-grain beta diversity in Palaearctic open vegetation: variability within and between biomes and vegetation types
2021
Aims: To quantify how fine-grain (within-plot) beta diversity differs among biomes and vegetation types. Study area: Palaearctic biogeographic realm. Methods: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database spanning broad geographic and ecological gradients. Next, we calculated the slope parameter (z-value) of the power-law species–area relationship (SAR) to use as a measure of multiplicative beta diversity. We did this separately for vascular plants, bryophytes and lichens and for the three groups combined (complete vegetation). We then tested whether z-values differed between biomes, ecological-physi…
A new calibration of the effective scattering albedo and soil roughness parameters in the SMOS SM retrieval algorithm
2017
Abstract This study focuses on the calibration of the effective vegetation scattering albedo (ω) and surface soil roughness parameters (H R , and N Rp , p = H,V) in the Soil Moisture (SM) retrieval from L-band passive microwave observations using the L-band Microwave Emission of the Biosphere (L-MEB) model. In the current Soil Moisture and Ocean Salinity (SMOS) Level 2 (L2), v620, and Level 3 (L3), v300, SM retrieval algorithms, low vegetated areas are parameterized by ω = 0 and H R = 0.1, whereas values of ω = 0.06 − 0.08 and H R = 0.3 are used for forests. Several parameterizations of the vegetation and soil roughness parameters (ω, H R and N Rp , p = H,V) were tested in this study, tre…
Steppes of Southern Siberia - Experiences from the 6th EDGG Research Expedition to Khakassia, Russia (22 July – 1 August 2013)
2013
The 6th EDGG Research Expedition took place in summer 2013 in the Kuznetsky Alatau Mountains, part of the Altai-Sayanian mountain region (Republic of Khakassia, Russia). A group of 14 scientists from seven countries studied the variety of steppe vegetation in two regions of the "Khakassky" Reserve – Lake Itkul (Shira region) and Podzaploty (Ordzhenikidzevsky region). Standardised sampling procedures including nested-plot series and phytosociological relevés of 10-m2 plots were used to sample steppes of European-Siberian (Festuco-Brometea) and Central Asian (Cleistogenetea squarrosae) types. All terricolous plants present in the plots were sampled, including perennial and annual vascular pla…
Assessing plant diversity and composition in grasslands across spatial scales: the standardised EDGG sampling methodology
2016
This paper presents the details of the EDGG sampling methodology and its underlying rationales. The methodology has been applied during EDGG Research Expeditions and EDGG Field Workshops since 2009, and has been subsequently adopted by various other researchers. The core of the sampling are the EDGG Biodiversity Plots, which are 100‐m2 squares comprising, in two opposite corners, nested‐plot series of 0.0001, 0.001, 0.01, 0.1, 1 and 10 m2 square plots, in which all terricolous vascular plants, bryophytes and lichens are recorded using the shoot presence method. In the 10‐m2 plots, species cover is also estimated as a percentage and various environmental and structural parameters are recorde…
Fusion of CNN and sparse representation for threat estimation near power lines and poles infrastructure using aerial stereo imagery
2021
Abstract Fires or electrical hazards and accidents can occur if vegetation is not controlled or cleared around overhead power lines, resulting in serious risks to people and property and significant costs to the community. There are numerous blackouts due to interfering the trees with the power transmission lines in hilly and urban areas. Power distribution companies are facing a challenge to monitor the vegetation to avoid blackouts and flash-over threats. Recently, several methods have been developed for vegetation monitoring; however, existing methods are either not accurate or could not provide better disparity map in the textureless region. Moreover, are not able to handle depth discon…
Machine Learning Methods for Spatial and Temporal Parameter Estimation
2020
Monitoring vegetation with satellite remote sensing is of paramount relevance to understand the status and health of our planet. Accurate and constant monitoring of the biosphere has large societal, economical, and environmental implications, given the increasing demand of biofuels and food by the world population. The current democratization of machine learning, big data, and high processing capabilities allow us to take such endeavor in a decisive manner. This chapter proposes three novel machine learning approaches to exploit spatial, temporal, multi-sensor, and large-scale data characteristics. We show (1) the application of multi-output Gaussian processes for gap-filling time series of…
FIRElinks. Fire in the Earth System: Science & Society
2020
FIRElinks is a EU-spanning network of scientists and practitioners involved in forest fire research and land management with backgrounds such as fire dynamics, fire risk management, fire effects on vegetation, fauna, soil and water, and socio-economic, historical, geographical, political perception and land management approaches. FIRElinks connect communities from different scientific and geographic backgrounds, allowing the discussion of different experiences and the emergence of new approaches to fire research. The main aim of FIRElinks is to power synergistic collaborations between European research groups and stakeholders with the objective to synthesise the existing knowledge and exper…
Analyse spectrale et texturale de données à haute résolution pour la détection automatique des maladies de la vigne
2019
‘Flavescence dorée’ is a contagious and incurable disease present on the vine leaves. In order to contain the infection, the regulations require growers to control each of the vine rows and to remove the suspect vine plants. This monitoring is done on foot during the harvest and mobilizes many people during a strategic period for viticulture. In order to solve this problem, the DAMAV project (Automatic detection of Vine Diseases) aims to develop a solution for automated detection of vine diseases using a micro-drone. The goal is to offer a turnkey solution for wine growers. This tool will allow the search for potential foci, and then more generally any type of vine diseases detectable on th…