On the photoreactivity of some hardwood species studied by their leaf characteristics

1970 ◽  
Vol 23 ◽  
Author(s):  
M. Van Miegroet
Keyword(s):  
Morphological Characteristics ◽  
Vegetation Period ◽  
Forest Stand ◽  
Light Environment ◽  
Light Radiation ◽  
Light Conditions ◽  
Site Factors ◽  
Leaf Characteristics ◽  
Single Tree ◽  
Changing Light

A  certain number of measurable characteristics of tree leaves (morphological  characteristics, absorption of light radiation, intensity of respiration and  photosynthesis) are clearly linked with the presence of physiologically  active pigments in the leaves.     Leaf characteristics are highly and inequally influenced by changing  conditions of light environment, especially those related to light intensity,  light quality and duration of the daily illumination period. These  modifications do not only apply to light radiation as created under  laboratory conditions, but also to light conditions ensuing from the place in  the crown of a single tree, the social position of the tree in a forest stand  and the site factors in general.     There are also changes taking place due to the progression of the  vegetation period, at the end of which all species are less tolerant or more  light demanding. The reaction of the leaves towards light radiation out of  different regions of the spectrum is also different. The so-called blue light  radiation (λmax = 440 nm) seems to be of the greatest importance in this  relation, as species react quite different to its action.     The biggest variation in leaf characteristics due to changing light  environment was measured for oak and beech, which both react quickly and are  qualified as 'photolabile species'. No important variations occur in leaves  of ash and maple, which therefore are qualified as 'photostable species'.      As a consequence of variable reactions to changing light conditions, the  relationships between the species are continually modified, even in such a  way that their potential for dominance is not constant.     The classical division into tolerant and intolerant species or  classification of the species based upon the degree of light demand, is  highly inaccurate and it seems preferable to speak of relative light demands  and relative tolerance. All these observations and conclusions bring about a  clear confirmation of the necessity to recognize the individuality of the  single tree, the special character of each growth condition, the own  structure of each forest stand, the specific reaction to one sided  modifications of environmental factors. This is especially important for an  intensive sylvicultural practice.     They also prove the necessity for more physiological and biochemical  research to arrive at a better understanding of growth and its mechanism.      Sylviculture in fact must try to regulate, on an expanded scale, the  phenomens of growth, which is the exchange, absorption and transformation of  energy.     A practical interpretation and regulation of fundamental laws of physiology  and growth will be possible as soon as a clinical form of sylviculture is  created and the adequate instrumentarium developed.

scholarly journals Phytochrome interacting factors 4 and 5 control seedling growth in changing light conditions by directly controlling auxin signaling

2012 ◽  
Vol 71 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Patricia Hornitschek ◽  
Markus V. Kohnen ◽  
Séverine Lorrain ◽  
Jacques Rougemont ◽  
Karin Ljung ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Auxin Signaling ◽  
Light Conditions ◽  
Changing Light

scholarly journals A Method of Fast Segmentation for Banana Stalk Exploited Lightweight Multi-Feature Fusion Deep Neural Network

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 66
Author(s):  
Tianci Chen ◽  
Rihong Zhang ◽  
Lixue Zhu ◽  
Shiang Zhang ◽  
Xiaomin Li
Keyword(s):  
Neural Network ◽  
Execution Time ◽  
Deep Neural Network ◽  
Feature Fusion ◽  
Frame Rate ◽  
Light Conditions ◽  
Segmentation Method ◽  
Segmentation Accuracy ◽  
Automatic Picking ◽  
Changing Light

In an orchard environment with a complex background and changing light conditions, the banana stalk, fruit, branches, and leaves are very similar in color. The fast and accurate detection and segmentation of a banana stalk are crucial to realize the automatic picking using a banana picking robot. In this paper, a banana stalk segmentation method based on a lightweight multi-feature fusion deep neural network (MFN) is proposed. The proposed network is mainly composed of encoding and decoding networks, in which the sandglass bottleneck design is adopted to alleviate the information a loss in high dimension. In the decoding network, a different sized dilated convolution kernel is used for convolution operation to make the extracted banana stalk features denser. The proposed network is verified by experiments. In the experiments, the detection precision, segmentation accuracy, number of parameters, operation efficiency, and average execution time are used as evaluation metrics, and the proposed network is compared with Resnet_Segnet, Mobilenet_Segnet, and a few other networks. The experimental results show that compared to other networks, the number of network parameters of the proposed network is significantly reduced, the running frame rate is improved, and the average execution time is shortened.

Acclimation to changing light conditions of long-term shade-grown beech (Fagus sylvatica L.) seedlings of different geographic origins

Trees ◽  
1998 ◽  
Vol 12 (6) ◽  
pp. 326-333 ◽  
Author(s):  
R. Tognetti ◽  
Gianfranco Minotta ◽  
Simone Pinzauti ◽  
Marco Michelozzi ◽  
Marco Borghetti
Keyword(s):  
Fagus Sylvatica ◽  
Light Conditions ◽  
Geographic Origins ◽  
Fagus Sylvatica L ◽  
Changing Light

scholarly journals Gübrelemenin Kayacık (Ostrya carpinifolia Scop.) Fidanlarının Morfolojik Gelişimine Etkisi

2016 ◽  
Vol 4 (10) ◽  
pp. 813 ◽  
Author(s):  
Şemsettin Kulaç ◽  
Özge Yıldız
Keyword(s):  
Morphological Characteristics ◽  
Vegetation Period ◽  
Morphological Characters ◽  
Morphological Development ◽  
Compound Fertilizer ◽  
Seedling Length ◽  
Collar Diameter ◽  
Root Collar ◽  
Ostrya Carpinifolia ◽  
Made In

In this study, in order to help the mass production of seedlings, the effect of fertilization on the morphological development of hornbeam leafy European hophornbeam (Ostry carpinifolia Scop) seedlings were investigated. For this, seedlings, which were obtained from the seeds coming from different European hophornbeam populations (Düzce-Yığılca, Antalya-Finike, Antalya-Akseki, Kastamonu-Şehdağ ve Adana-Saimbeyli) from various parts of Turkey, were used. European hophornbeam seedlings were treated with different fertilizers, including urea, ammonium sulphate, compound fertilizer 15-15-15 and 20-20-0, and 6-9 months Osmocote release fertilizer, and effects of these fertilizers on the morphological characters were investigated. Fertilization contained the same amount of nitrogen, and was made in three different ways; (1) mixing with habitat, (2) topical application and (3) liquid application. The development of germinated European hophornbeam seeds, which were spring-sowed in the same medium were monitored during the vegetation period. At the end of vegetation period, seedlings were removed from the soil and morphological characteristics of root (seedling length, root collar diameter, root length, fresh root and stem weight of the seedlings, dried root and stem weight of the seedlings and bud number) were measured. As a result, it was observed that fertilization positively affects the development of seedlings and depending on the fertilization type the seedlings of European hophornbeam populations were found to exhibit different improvements/growing. In addition, 6-9 months Osmocote release fertilizers were determined to be the best fertilizers affecting the morphological (diameter and height) development of European hophornbeam populations effectively, and among the populations, Düzce and Kastamonu populations showed the best improvement/growing.

scholarly journals The strategy of creating highly productive forms of radish, adapted for cultivation under artificial light conditions

2019 ◽  
Vol 1 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. A. Kochetov ◽  
N. G. Sinyavina
Keyword(s):  
Small Volume ◽  
Morphological Characteristics ◽  
Intraspecific Diversity ◽  
Artificial Light ◽  
Light Conditions ◽  
Early Maturity ◽  
Artificial Lighting ◽  
First And Second Generation ◽  
Incandescent Lamps ◽  
Different Origin

The strategy of creating new radish forms adapted for cultivation under artificial lighting was developed and implemented. It was based on the original methodology of obtaining transgressive forms of various cultures with a predictable complex of economically valuable properties. Plants were grown in controlled conditions, under incandescent lamps DNAZ-400 (12 hours photoperiod, irradiation of 40-60 W/m2 PAR), in a small volume of the root medium. At the first stage, the intraspecific diversity of radish (26 varieties of different origin) under artificial lighting has been studied. Differences between varieties were determined for the complex of selective-valuable characteristics (early maturity, productivity, morphological characteristics). The most productive varieties are revealed, as well as varieties donors of economically valuable properties that are realized under artificial lighting at a short day and high temperature. Parent pairs have been selected for the subsequent receipt of highly productive transgressive forms using the original breeding methodology. The evaluation of hybrids of the first and second generation showed the presence of heterosis on the mass of the root up to 230% in various combinations of hybridization and revealed promising transgressive forms.

scholarly journals Formation of reproductive organs in an early-ripening soybean variety, depending on the daylight duration

2021 ◽  
Vol 36 ◽  
pp. 02005
Author(s):  
Valentina Sinegovskaya ◽  
Anna Levina
Keyword(s):  
Growth And Development ◽  
Growing Season ◽  
Vegetation Period ◽  
Reproductive Organs ◽  
Light Conditions ◽  
Soybean Variety ◽  
Seed Productivity ◽  
Early Ripening ◽  
Soybean Plants ◽  
Sowing Period

To study the reaction of an early-ripening soybean variety to the formation of plant reproductive organs under the influence of different length of daylight hours, studies of 2 sowing periods in a growing house with a new early-ripening variety Sentyabrinka of the FSBSI FRC VNII of Soybean were conducted. Artificial reduction of the daylight duration to 8 hours was established from the phase of the 3rd triple leaf with alternating day and night periods in each variant 7 times during the growing season. The control was plants whose growth and development took place in natural light conditions. According to the research results, it was found that the change in the daylight duration during the vegetation period had a significant impact on the duration of the phases of plant growth and development, the growing season as a whole. When sowing soybeans on May 28 with a natural daylight, the height of plants and their seed productivity were higher than those of plants with a shortened daylight. At this sowing period, the highest productivity was obtained from one plant – 9.3 g, which is 1.0 g more compared to soybean plants with a sowing period of June 3. The growth of plants, the formation of reproductive organs and the seed productivity of the early-repining variety Sentyabrinka depended on the duration of daylight, which can be regulated by the sowing period.

scholarly journals Transformation of even-aged spruce stands at the School Forest Enterprise Kostelec nad Černými lesy: Structure and final cutting of mature stand

2012 ◽  
Vol 52 (No. 4) ◽  
pp. 158-171 ◽  
Author(s):  
J. Remeš
Keyword(s):  
Forest Stand ◽  
Growth Potential ◽  
Main Criterion ◽  
Individual Tree ◽  
Main Method ◽  
Single Tree ◽  
Mature Stand ◽  
Spruce Stands ◽  
Individual Trees ◽  
Very High

This paper deals with the transformation of pure even-aged forest stands to mixed and more uneven-aged stands on an example of selected even-aged Norway spruce stands in the School Forest Enterprise (SFE) in Kostelec nad Černými lesy. A forest stand where individual tree felling was used as the main method of forest stand regeneration was chosen as a conversion example. The main criterion of tree maturity is the culmination of mean volume increment of a single tree. The analyses confirmed a very high variability in the growth potential of individual trees. The potential and actual increment was strongly influenced by the stand position of tree and by crown release. These results show a high potential level of tree growth even at the age of 120 years. From 30% to 9% of all trees on particular experimental plots achieved felling maturity.

scholarly journals Combining GF-2 and Sentinel-2 Images to Detect Tree Mortality Caused by Red Turpentine Beetle during the Early Outbreak Stage in North China

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 172 ◽  
Author(s):  
Zhan ◽  
Yu ◽  
Li ◽  
Ren ◽  
Gao ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Spatial Scales ◽  
Binary Classification ◽  
Insect Pest ◽  
Forest Stand ◽  
Machine Learning Algorithms ◽  
Classification And Regression Tree ◽  
Support Vector ◽  
Single Tree ◽  
Sentinel 2

In recent years, the red turpentine beetle (RTB) (Dendroctonus valens LeConte) has invaded the northern regions of China. Due to the short invasion time, the outbreak of tree mortality corresponded to a low level of damage. Important information about tree mortality, provided by remote sensing at both single-tree and forest stand scale, is needed in forest management at the early stages of outbreak. In order to detect RTB-induced tree mortality at a single-tree scale, we evaluated the classification accuracies of Gaofen-2 (GF2) imagery at different spatial resolutions (1 and 4 m) using a pixel-based method. We also simultaneously applied an object-based method to 1 m pan-sharpened images. We used Sentinel-2 (S2) imagery with different resolutions (10 and 20 m) to detect RTB-induced tree mortality and compared their classification accuracies at a larger scale—the stand scale. Three kinds of machine learning algorithms—the classification and regression tree (CART), the random forest (RF), and the support vector machine (SVM)—were applied and compared in this study. The results showed that 1 m resolution GF2 images had the highest classification accuracy using the pixel-based method and SVM algorithm (overall accuracy = 77.7%). We found that the classification of three degrees of damage percentage within the S2 pixel (0%, <15%, and 15% < x < 50%) was not successful at a forest stand scale. However, 10 m resolution S2 images could acquire effective binary classification (<15%: overall accuracy = 74.9%; 15% < x < 50%: overall accuracy = 81.0%). Our results indicated that identifying tree mortality caused by RTB at a single-tree and forest stand scale was accomplished with the combination of GF2 and S2 images. Our results are very useful for the future exploration of the patterns of spatial and temporal changes in insect pest transmission at different spatial scales.

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