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Spatial mapping of the leaf area index using remote sensing and ground measurements - the Biebrza National Park case study

Ignar Stefan, Szporak-Wasilewska Sylwia, Gregorczyk Małgorzata

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 2

175--185

EN

The purpose of the described research was an attempt to estimate the leaf area index (LAI) parameter describing the structure of the vegetation based on the Landsat 5TM satellite imagery and field measurements made with the use of an optical plant canopy analyzer. The study was carried out in north-eastern Poland in the Biebrza river valley within the boundaries of the Biebrza National Park during the growing season of the year 2007. There were 13 spectral indices given in the literature known to be correlated with the LAI. The highest coefficient of determination and the highest correlation coefficient were obtained for the normalized difference vegetation index (NDVI) and the soil adjusted vegetation index (SAVI) indices for the wetland areas in the Biebrza river valley. The field measurements of the leaf area index and its spatial representation on satellite image show that the vegetation of natural river valleys is characterized by high spatial and seasonal variability. The study of the LAI on such large natural areas that are extensively used also requires knowledge of the methods of land use and the application of individual agrotechnical measures.

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Using Vegetative Indices to Quantify Agricultural Crop Characteristics

Kokhan Svitlana, Vostokov Anatoliy

Journal of Ecological Engineering

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2020

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Vol. 21, nr 4

120--127

EN

In this study, the winter wheat aboveground biomass (AGB), leaf area index (LAI) and leaf nitrogen concentration (LNC) were estimated using the vegetation indices, derived from a high spatial resolution Pleiades imagery. The AGB, LAI and LNC estimation equations were established between the selected VIs, such as NDVI, EVI and SAVI. Regression models (linear and exponential) were examined to determine the best empirical regression equations for estimating the crop characteristics. The results showed that all three vegetation indices provide the AGB, LAI and LNC estimations. The application of NDVI showed the smallest value of RMSE for the aboveground biomass estimation at stem elongation and heading of winter wheat. EVI gave the best significant estimation of LNC and showed better results to quantify winter wheat vegetation characteristics at stem elongation phase. This study demonstrated that Pleiades high spatial resolution imagery provides in-situ crop monitoring.

3

Visual Quality and Morphological Responses of Rosemary Plants to UV-B Radiation and Salinity Stress

Hamidi-Moghaddam Abolghasem, Arouiee Hossein, Moshtaghi Nasrin, Azizi Majid, Shoor Mahmoud, Sefidkon Fatemeh

Journal of Ecological Engineering

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2019

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Vol. 20, nr 2

34--43

EN

In order to understand the effects of ultraviolet-B (UV-B) radiation and salinity stress on the visual quality and morphological parameters, one-year-old seedlings of rosemary (Rosmarinus officinalis L.) were grown under three UV-B levels (0, 4.32, 6.05 kJ m-2 d-1) and four salinity regimes (Control, 50, 100 and 150 mM NaCl) under greenhouse conditions. The results showed that enhanced UV-B radiation increased visual quality, growth index, plant biomass, shoot/root ratio, number of branches and leaves, leaf fresh and dry weight, leaf area index, specific leaf area, leaf thickness. The UV-B radiation had no significant effect on root length; however, shoot height, length of axillary shoots, length of inter node, leaf area, leaf length and width and concentration of chlorophyll b were negatively impacted by the UV-B radiation. On the other hand, salinity caused a significant decrease in plant biomass, root length, shoot height, shoot/root ratio, length of axillary shoots, length of inter node, number of branches and leaf area, leaf area index, leaf length and width, leaf fresh and dry weight, specific leaf area and concentration of Photosynthetic pigments. However, the number leaves and leaf thickness significantly increased under NaCl salinity treatments. Visual quality and growth index were hardly affected by increasing salinity until 100 mM, but declined clearly at 150 mM NaCl salinity. The interaction between UV-B irradiation and salinity showed that pre-treatment with UV-B irradiation alleviated the harmful effects of NaCl and improved the visual quality rosemary plants.

4

Feasibility study of vegetation indices derived from Sentinel-2 and PlanetScope satellite images for validating the LAI biophysical parameter to monitoring development stages of winter wheat

Gurdak Radoslaw, Grzybowski Patryk

Geoinformation Issues

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2018

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Vol. 10, no. 1(10)

27--35

EN

The main objective of the presented work is to assess applicability of vegetation indices derived from non-commercial and commercial satellites for monitoring development stages of winter wheat. Two types of data were used in the study: Sentinel-2 and PlanetScope images. Various vegetation indices were derived from these data and correlated with ground measured LAI values. The results of the study revealed that there is a good relationship between satellite based indices – Normalized Difference Vegetation Index – NDVI, Enhanced Vegetation Index – EVI, Soil Adjusted Vegetation Index – SAVI and ground based LAI, but strength of this relation depends on the phase of crop development. Sentinel-2 and PlanetScope data are suitable for estimating LAI with high accuracy and their precision for LAI determination is very similar. Depending on availability, they can be used interchangeably. The highest correlation between ground measured LAI and vegetation indices for Sentinel-2 appeared SAVI – r = 0.862 (phase: early tillering) and for PlanetScope NDVI – r = 0.667 (phase: ripening). Compatibility of average LAI values derived from PlanetScope and Sentinel-2 images are 33.21% and 10.63%.

PL

Głównym celem prezentowanej pracy jest ocena przydatności wskaźników roślinnych pochodzących z komercyjnego i niekomercyjnego satelity do monitorowania faz rozwoju pszenicy ozimej. W badaniach wykorzystano dwa typy danych: zobrazowania satelitarne PlanetScope i Sentinel-2. Na ich podstawie wygenerowano różne wskaźniki wegetacji i skorelowano je z wartościami LAI pomierzonymi w terenie. Wyniki analiz wykazały, że istnieje wysoki związek pomiędzy wskaźnikami NDVI, EVI i SAVI a naziemnymi wartościami LAI. Okazało się, że siła tej zależności zależy od fazy rozwoju upraw. Stwierdzono, że zobrazowania satelitarne Sentinel-2 i PlanetScope pozwalają na szacowania LAI z dużą dokładnością, a dokładność obu danych jest podobna. W zależności od dostępności bezchmurnych zdjęć, obrazy można stosować zamiennie.

5

Związek między wskaźnikiem LAI a spektralnymi wskaźnikami roślinności na przykładzie wybranych gatunków roślin uprawnych

Uździcka B., Juszczak R., Sakowska K., Olejnik J.

Woda-Środowisko-Obszary Wiejskie

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2012

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T. 12, z. 2

283-311

PL

W pracy określono charakter i stopień wpływu wskaźnika powierzchni liści LAI na charakterystyki optyczne pokrywy roślinnej, opartych na promieniowaniu w przedziałach czerwieni i bliskiej podczerwieni dla obszaru rolniczego. Pomiary wykonano dla pięciu gatunków roślin (tzn. żyta ozimego, pszenicy ozimej, pszenżyta ozimego, ziemniaków i jęczmienia jarego), uprawianych na stacji doświadczalnej w Brodach (województwo wielkopolskie). LAI jest istotnym parametrem ekofizjologicznym. Obecnie szybko rozwijającą się techniką, służącą do szacowania charakterystyk biofizycznych pokrywy roślinnej, jest stosowanie pomiarów jej charakterystyk optycznych. Porownując wartości współczynnika determinacji R2, a także statystyczne miary dopasowania modelu, uzyskane dla różnych typów zależności (liniowej, logarytmicznej, wykładniczej, wielomianowej i potęgowej) i różnych gatunków roślin zauważono, że zależność analizowanej grupy spektralnych wskaźników roślinności od LAI jest nieliniowa, przez co jego szacunki na ich podstawie są obarczone stosunkowo dużym błędem (średnio 0,48 m²·m-²). Najwcześniej efekt saturacji występował dla najczęściej stosowanych wskaźników NDVI i SR. Dane wskazują także, że podczas szacunków LAI na podstawie większości spektralnych wskaźników roślinności, opartych na ρNIR i ρRED, znaczący wpływ mają zaburzające efekty tła glebowego, które najsilniej oddziałują na wartości NDVI. Wpływ ten okazał się być najmniejszy w przypadku SAVI, dla którego uzyskiwane wartości R² w warunkach zależności od LAI były, w porównaniu z pozostałymi analizowanymi wskaźnikami, najczśćciej największe. SAVI najlepiej sprawdza. się także jako wskażnik, na podstawie którego można modelować oczekiwane wartości LAI.

EN

The paper presents the character and effect of the leaf area index (LAI) on optical characteristics of plant cover based on radiation in the red and near infrared region for an agricultural area. Measurements were made for 5 plant species (winter rye, winter wheat, winter triticale, potatoes and spring barley) grown in experimental station in Brody (Wielkopolska Province). LAI is an important ecophysiological parameter. Measurement of optical characteristics is now a rapidly developing technique used to estimate bio-physical characteristics of plant cover. Comparison of determination coefficient R2 and statistical measures of model fitness for various types of relationships (linear, logarithm, exponential, polynomial, power) and for various plant species showed that the relationship between the analysed group of spectral plant indices and LAI was non-linear and hence burdened with relatively large error (mean 0.48 m²·m-²). The effect of saturation appeared earliest for most commonly used indices - NDVI and SR. Disturbing effects of soil background, which most strongly affect the NDVI values, expressed themselves when estimating LAI from most spectral plant indices based on ρNIR and ρRED. This effect was smallest for SAVI, for which R2 was highest as compared with other analysed indices. SAVI worked best as an index, based on which one may model the expected values of LAI.

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Ocena selektywności herbicydów stosowanych w monokulturze kukurydzy z wykorzystaniem wskaźnika powierzchni liści (LAI) i kąta nachylenia liści (MTA)

Gołębiowska H., Sekutowski T.

Inżynieria Rolnicza

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2007

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R. 11, nr 3 (91)

51-58

PL

Prowadzone przez wiele lat doświadczenia nad reakcją odmian kukurydzy na herbicydy wskazują, że środki te nie są całkowicie selektywne. Powszechnie stosowany w ochronie kukurydzy rimsulfuron powoduje w wielu przypadkach zmiany morfologiczne zahamowanie wzrostu i końcowym efekcie prowadzi do obniżenia plonowania. Poddane ocenie, w latach 2003-2005 odmiany Fatima i Blask na działanie rimsulfuronu i 2,4 D+florasulam, wykazały zróżnicowaną tolerancję na zawarte w środkach substancje biologicznie czynne. Fitotoksyczne oddziaływanie herbicydów na odmiany kukurydzy oceniano na podstawie pomiarów wysokości roślin w okresie intensywnego wzrostu oraz po wykształceniu wiech, liczby roślin, liczby kolb, masy kolb i MTZ oraz wysokości plonowania. Plon ziarna i masę tysiąca ziaren podano w przeliczeniu na 15% wilgotności. W wyniku aplikowania rimsulfuronu stwierdzono u mieszańca Fatima pojawienie się w różnym nasileniu, fitotoksycznych uszkodzeń typu odbarwienia oraz staśmienia liści i deformacje roślin, a po zastosowaniu 2,4 D+florasulam zahamowanie wzrostu i skręcenie liści, prowadzące do znacznego obniżenie wysokości roślin oraz do zmniejszenia liczby kolb, MTZ oraz plonu kolb i ziarna. Wrażliwość odmiany Fatima na stosowane herbicydy potwierdzają niskie indeksy LAI i wysokie MTA. Tolerancyjna odmiana Blask charakteryzowała się najwyższym indeksem LAI i najniższym kątem ustawienia liści MTA niezależnie od warunków pogodowych występujących w poszczególnych latach badań po zastosowaniu zarówno rimsulfuronu i 2,4 D+florasulam.

EN

Conducted for many years by authors experiments have shown that for many maize hybrids cultivated in Poland herbicides applied in maize are not quite selective. Some of them, particularly rimsulfuron cold cause morphological changes, growth inhibition and even decrease yielding. In the paper are presented results of experimental research on rimsulfuron and 2.4 D+florasulam influence on selected maize varieties in different conditions of weather course in vegetation seasons 2003- 2005. In experiments used measurements of leaf area index (LAI) and mean tip angle (MTA). LAI and MTA were determined with use of a LAI-2000 meter (LI-COR, USA) aty the beginning of BBCH 45 stage in four replications. In the unfavourable year 2004, when there was, up to reaching phase of complete maturity of maize, large deficit of thermal units and excessive content of moisture in soil, after treatment with above mentioned herbicides tested hybride Fatima of maize have reacted with yield decrease, lower leaf area index and highest mean tip angle. However for resistant variety Blask was noted highest LAI index and lowe mean tip after application by Mustang 306 EC and Titus 25 WG in three years of the study.

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Zastosowanie zdjęć hemisferycznych w badaniach ekosystemów leśnych

Strzeliński P.

Roczniki Geomatyki

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2006

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T. 4, z. 4

93-112

EN

The main aim of the study is to discuss basic assumptions of taking hemispherical photographs in the context of their practical use in forest inventory. The work encompasses methodology of taking digital hemispherical photographs. Hemispherical photographs are most often taken for research on ecological conditions of plants. Usually the aim of such research is to obtain information on the amount of light which reaches selected height above the ground. It is important to observe a few rules in taking photographs (overcast, camera leveling, sensitivity, shutter speed, maximum resolution). The best equipment for this purpose is a digital reflex camera and fish-eye lens with the angle 180°. Another solution is a digital reflex camera smaller than 35 mm with suitable converter which together with lens will allow to obtain circular photo with retained angle of 180°. Gap Light Analyzer and WinSCANOPY are the most frequently used software packages for analysis of hemispherical photos. The following elements are expected to be determined as a result of analyses based on hemispherical photographs: absolute amount of light registered at measurement levels, crown density structure, spatial variability of stand foliage, leaf area index, general description of crowns (crowns deformation, viability of lateral shoots) the condition of assimilatory organs (number of annuals, crown light and decrement of assimilatory organs, distortion and discoloration of assimilatory organs) relationship between tree density and natural regeneration The following attempts will be undertaken with the use of hemispherical photos: to estimate biomass of assimilatory organs, to estimate density of photons flow in the process of photosynthesis under canopies and in gaps of stand, to register the infrared scope of radiation (in order to examine assimilation organs in stands), to prepare a photomap of canopies. The study encompasses a brief review of literature, a list of possible devices with basic software.

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Vegetation structure at the breeding sites of the partridge (Perdix perdix L.) in Central Europe and its possible importance for population density

Wubbenhorst Dirk, Leuschner Christoph

Polish Journal of Ecology

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2006

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Vol. 54, nr 1

57-67

EN

This paper analyses the abundance of breeding pairs and the location of nesting sites of partridges as related to vegetation structure in the nest surroundings in two areas with very different partridge densities and arable landscape patterns (Central Germany and Eastern Poland). Study objective was to identify underlying causes of the more than 100 fold difference in population density of this species in these two areas of Central Europe. Our results suggests that the very limited availability of appropriate nesting habitats with an open canopy structure and low leaf area index is one of the key factors being responsible for the very low recent population density, and the past rapid decline, of partridge in the modern agricultural landscape of western Central Europe.