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Zmienność runa leśnego w grądzie wysokim rezerwatu Las Bielański pod wpływem ruchu turystycznego

100%

Grutkowska A.

Studia Ecologiae et Bioethicae

2010

vol. 8

issue 2

93-106

Las Bielański covers 150 hectares in area is a unique remnant of the ancient Mazowiecka Forest. At present 130 hectares out of 150 hectares are a nature reserve, where the influence of humans is limited only to tourist paths. The aim of this research was to estimate a possible impact of use the path by humans on the development of nearby plants. Namely, whether the presence of the path induces any changes, and if so, what sort and scope of the changes is seen. A 125 m long section of a tourist path, located in an oak-hornbeam association was chosen. Three sampling lines parallel to the path were traced: line A – 15-30 cm distant from the path’s edge, line B – 5 m away, and line C – about 10 m away from the path’s edge (Fig. 1). Plants were collected using sample squares of 0.1 m2 in area, distributed evenly along each line (25 samples per line, i.e., 75 samples altogether). The data collected in the field were analysed statistically. Most of the species exhibit clumped distribution of the amount of sprouts (Tab. 1). This phenomenon is seen in each line. In order to demonstrate the differences in abundance of sprouts, as well as differences in plant cover between the samples taken along the three lines, nonparametric statistics were applied – the Mann-Whitney test and Kruskal-Wallis ANOVA. The results of those analyses show for restricted plant cover in the line closest to the path: the percentage of the coverage and the number of sprouts per sample in line A are lower than those estimated for lines B and C (Fig. 3). The species occurring most frequently are those typical of the oak-hornbeam association. The estimate of frequency is the lowest for all the species directly in the closest vicinity of the path (Fig. 2). Seasonal variability is evident, too. No presence of animals was noticed within the distance of 5 m from the path’s edge. The majority of animal traces occurred around line C, about 10 m distance from the path. Particular attention was paid to distribution of hornbeams (Carpinus betulus) – the species in the oak-hornbeam association. No significant differences were found between the three lines as far the amount of hornbeam sprouts and frequency is concerned (Fig. 4 and 5). The number of sprouts of this species is the highest in spring, and it decreases gradually, due to heavy mortality of seedlings and juvenile specimens, with progressive light shortage. It means, the tourist traffic is not the only factor affecting plant abundance.

Forest species mapping using airborne hyperspectral APEX data

61%

Tagliabue G., Panigada C., Colombo R., Fava F., Cilia C., Baret F., Vreys K., Meuleman K., Rossini M.

Miscellanea Geographica. Regional Studies on Development

2016

vol. 20

issue 1

28-33

The accurate mapping of forest species is a very important task in relation to the increasing need to better understand the role of the forest ecosystem within environmental dynamics. The objective of this paper is the investigation of the potential of a multi-temporal hyperspectral dataset for the production of a thematic map of the dominant species in the Forêt de Hardt (France). Hyperspectral data were collected in June and September 2013 using the Airborne Prism EXperiment (APEX) sensor, covering the visible, near-infrared and shortwave infrared spectral regions with a spatial resolution of 3 m by 3 m. The map was realized by means of a maximum likelihood supervised classification. The classification was first performed separately on images from June and September and then on the two images together. Class discrimination was performed using as input 3 spectral indices computed as ratios between red edge bands and a blue band for each image. The map was validated using a testing set selected on the basis of a random stratified sampling scheme. Results showed that the algorithm performances improved from an overall accuracy of 59.5% and 48% (for the June and September images, respectively) to an overall accuracy of 74.4%, with the producer’s accuracy ranging from 60% to 86% and user’s accuracy ranging from 61% to 90%, when both images (June and September) were combined. This study demonstrates that the use of multi-temporal high-resolution images acquired in two different vegetation development stages (i.e., 17 June 2013 and 4 September 2013) allows accurate (overall accuracy 74.4%) local-scale thematic products to be obtained in an operational way.

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1 Miscellanea Geographica. Regional Studies on Development

1 Studia Ecologiae et Bioethicae

1 Baret F.

1 Cilia C.

1 Colombo R.

1 Fava F.

1 Grutkowska A.

1 Meuleman K.

1 Panigada C.

1 Rossini M.

1 Tagliabue G.

1 Vreys K.

1 2016

1 2010

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Zmienność runa leśnego w grądzie wysokim rezerwatu Las Bielański pod wpływem ruchu turystycznego

Forest species mapping using airborne hyperspectral APEX data