Search results for "VEGETATION"

Misión FLEX (Fluorescence Explorer): Observación de la fluorescencia por teledetección como nueva técnica de estudio del estado de la vegetación terr…

2014

[EN] FLEX (Fluorescence EXplorer) is a candidate for the 8th ESA’s Earth Explorer mission. Is the first space mission specifically designed for the estimation of vegetation fluorescence on a global scale. The mission is proposed to fly in tandem with the future ESA´s Sentinel-3 satellite. It is foreseen that the information obtained by Sentinel-3 will be supplemented with that provided by FLORIS (Fluorescence Imaging Spectrometer) onboard FLEX. FLORIS will measure the radiance between 500 and 800 nm with a bandwidth between 0.1 nm and 2 nm, providing images with a 150 km swath and 300 m pixel size. This information will allow a detailed monitoring of vegetation dynamics, by improving the me…

Global vegetation monitoring through multitemporal analysis of pathfinder AVHRR land database

2005

We have applied a Land Surface Temperature algorithm to the whole Pathfinder AVHRR Land (PAL) database, aiming at studying the evolution of the vegetation at a global scale. The Land Surface Temperature parameter, along with NDVI, will allow retrieving vegetation changes between July 1981 and September 2001. We have also built a classification which takes into account both vegetation variations and thermal patterns, from NDVI and Air Temperature at 2 meters height data. This classification allows differentiating areas which present close vegetation changes throughout the year, but totally different climates, as for example in mountainous and semiarid regions. The main quality of this classi…

Reconstruction of palaeovegetation and sedimentation conditions in the area of ancient Lake Burtnieks, northern Latvia

2010

Palaeobotanical investigations were carried out with the aim of reconstructing the development of palaeovegetation and formation of sediments in the northeastern area of ancient Lake Burtnieks. Pollen and plant macroremain studies provide information on vegetation development in the surroundings of the lake, including Stone Age settlements of Braukšas I and Braukšas II. Results of the investigations indicate that the development of vegetation together with sedimentation conditions in the palaeolake have changed since the Younger Dryas until today. Vegetation composition varies in different parts of the ancient Lake Burtnieks area due to past changes in lake water level which reached differe…

Relationship between the seed rain and the establishment of vegetation in two areas abandoned after peat harvesting

1987

In this study the number and species composition of diaspores dispersing into two newly abandoned peat harvesting areas in Finland were investigated. In an area abandoned six years earlier a total of 2978 living seeds m−2, representing 18 species, was captured by using water-filled traps during two summers. In a one-year-old succession area the total number of living seeds m−2 was 2241, representing 16 plant species. The soil seed banks were found to be empty of viable seeds. In neither area there appeared to be any relation between number of dispersing seeds and of plant individuals of the same species in the pioneer vegetation. It is suggested that unfavourable conditions on the soil surf…

Water quality in cutaway peatland lakes in Seda mire, Latvia

2011

Remediation of industrially-milled peatland is an important task in the sustainable management of natural resources. Several approaches for wetland restoration, depending on local climatic and hydrological conditions, topography, physico-chemical properties of peat, as well as peat mining techniques, have been developed worldwide. However, most of the restoration activities include regulation of hydrological regime and surface topography in order to reintroduce typical bog vegetation, especially, Sphagnum cover, and to restore the peatland’s ecosystem close to its original conditions (Gorham and Rochefort, 2003; Farrell and Doyle, 2003; Lamers et al., 2002). In many countries, a significant…

Vegetation of rock clefts and ledges in the Pamir Alai Mts, Tajikistan (Middle Asia)

2014

AbstractThe paper presents the results of phytosociological research conducted on the vegetation of rock clefts and ledges in the Pamir-Alai Mountains (Tajikistan, Middle Asia). During the field studies, done in 2010–2012, 101 phytosociological relevés were taken. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. Communities of calcareous rock clefts and ledges with small soil amounts from several ranges (Zeravshan Mts, Hissar Mts, Hazratishokh Mts, Darvaz Mts, Rushan Mts and Vanch Mts), inhabiting mainly the alpine and subnival zone, have been described. A synopsis of the rock communities of the Pamir-Alai is proposed. In the examined vegetation plots 77 va…

NDVI seasonal amplitude and its variability

2008

NDVI (Normalized Difference Vegetation Index) is a remotely sensed index of vegetation greenness. Its yearly cycle gives information on vegetation type or health, and monitoring its temporal evolut...

Strange vegetation: Emotional undercurrents of Tove Jansson’s Moominvalley in November

2018

Abstract This article investigates the emotional undercurrents of Tove Jansson’s Moominvalley in November. I argue that one of the main characters of Jansson’s book is the autumn forest that surrounds the abandoned Moomin house. The decomposing forest is not just an emblem of the inner lives of the guests that gather in the house but is an active character itself: an ambiguous life form that creeps in the house and must be expelled from its living core. I further demonstrate that the emotion of disgust has a crucial role in Jansson’s narrative, and that an adequate analysis of the intentional content of disgust allows us to see what is at issue in the relations between the characters. In my…

Changes in the Breeding Bird Fauna, Waterbird Populations in Particular, on Lake Engure (Latvia) over the Last 50 Years

2005

The nesting bird fauna (186 species) of Lake Engure and its surroundings has changed considerably over the last 50 years: 18 species have appeared as newcomers (among them 56% of southern, 6% of northern origin), 10 species have ceased nesting (among them 60% of northern, 10% of southern origin). These changes might be explained by global warming. Dramatic changes recorded in all waders can be accounted for by the local habitat loss and a general decline in wider geographic ranges. The Black-headed Gull (Larus ridibundus) population increased from 200 pairs in 1940s to 34,000 pairs in 1986, and then declined to 4,200 pairs in 2002. Nesting duck (all species combined) numbers and their nesti…

2015

In this study we present a hyperspectral flying goniometer system, based on a rotary-wing unmanned aerial vehicle (UAV) equipped with a spectrometer mounted on an active gimbal. We show that this approach may be used to collect multiangular hyperspectral data over vegetated environments. The pointing and positioning accuracy are assessed using structure from motion and vary from σ = 1° to 8° in pointing and σ = 0.7 to 0.8 m in positioning. We use a wheat dataset to investigate the influence of angular effects on the NDVI, TCARI and REIP vegetation indices. Angular effects caused significant variations on the indices: NDVI = 0.83–0.95; TCARI = 0.04–0.116; REIP = 729–735 nm. Our analysis high…