scholarly journals A proposed procedure for the analysis of large phytosociological data sets in the classification of South African grasslands

Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
G.J. Bredenkamp ◽  
H. Bezuidenhout

A procedure for the effective classification of large phytosociological data sets, and the combination of many data sets from various parts of the South African grasslands is demonstrated. The procedure suggests a region by region or project by project treatment of the data. The analyses are performed step by step to effectively bring together all releves of similar or related plant communities. The first step involves a separate numerical classification of each subset (region), and subsequent refinement by Braun- Blanquet procedures. The resulting plant communities are summarised in a single synoptic table, by calculating a synoptic value for each species in each community. In the second step all communities in the synoptic table are classified by numerical analysis, to bring related communities from different regions or studies together in a single cluster. After refinement of these clusters by Braun-Blanquet procedures, broad vegetation types are identified. As a third step phytosociological tables are compiled for each iden- tified broad vegetation type, and a comprehensive abstract hierarchy constructed.

2020 ◽  
Vol 57 (1) ◽  
pp. 29-54 ◽  
Author(s):  
Daniele Viciani ◽  
Marisa Vidali ◽  
Daniela Gigante ◽  
Rossano Bolpagni ◽  
Mariacristina Villani ◽  
...  

This study provides a first step toward the knowledge of the alien-dominated and co-dominated plant communities present in Italy. The first ever checklist of the alien phytocoenoses described or reported in literature for the Italian territory has been compiled, produced by data-mining in national and local thematic literature. The resulting vegetation-type draft-list has been checked in the light of the most recent syntaxonomic documentation and updated with regards to syntaxonomy and nomenclature, with special reference to the frame proposed in the Italian Vegetation Prodrome. The list includes 27 vascular and one bryophyte vegetation classes, hosting 194 low rank alien-dominated syntaxa. The different vegetation types detected for each syntaxonomic class and macro-vegetation group, defined by physiognomical and ecological attributes, are discussed.


Koedoe ◽  
1998 ◽  
Vol 41 (2) ◽  
Author(s):  
A.E. Cauldwell ◽  
U. Zieger ◽  
M.G. Bingham ◽  
G.J. Bredenkamp

A phytosociological analysis of the physical environment and the natural plant communities of Mtendere Game Ranch in the Chibombo District of the Central Province of Zambia is presented. A TWINSPAN classification and DECORANA ordination based upon 69 releves revealed three vegetation types, grassland, woodland and thicket, that are subdivided into the following plant communities: Dambo, Munga Woodland, Miombo Woodland, Termitaria and Deciduous Thicket. The natural vegetation of Mtendere Game Ranch is separated into fire management units on the basis of the vegetation types.


Bothalia ◽  
1978 ◽  
Vol 12 (3) ◽  
pp. 531-536
Author(s):  
F. Van der Meulen

The Sourish Mixed Bushveld of the western Transvaal is being studied using the Braun-Blanquet method. The vegetation includes: (a) woodland of cooler sites on crests and steeper south-facing slopes; (b) woodland of warmer sites on gentle north-facing slopes; and (c) grassland and woodland of plains with slight relief on calcareous substrata. Six vegetation types are provisionally described in terms of their main structure, floristic composition (dominant and characteristic species) and habitat. The syntaxonomic relationships between these types are mentioned briefly and the types are considered in terms of Acocks’s classification of South African veld types.


2019 ◽  
pp. 135-142
Author(s):  
K. V. Ivanova ◽  
A. M. Lapina ◽  
V. V. Neshataev

The 2nd international scientific conference «Fundamental problems of vegetation classification» took place at the Nikitskiy Botanical Garden (Yalta, Republic of Crimea, Russia) on 15–20 September 2019. There were 56 participants from 33 cities and 43 research organizations in Russia. The conference was mostly focused on reviewing the success in classification of the vegetation done by Russian scientists in the past three years. The reports covered various topics such as classification, description of new syntaxonomical units, geobotanical mapping for different territories and types of vegetation, studies of space-time dynamics of plant communities. The final discussion on the last day covered problems yet to be solved: establishment of the Russian Prodromus and the National archive of vegetation, complications of higher education in the profile of geobotany, and the issue of the data leakage to foreign scientific journals. In conclusion, it was announced that the 3rd conference in Nikitskiy Botanical Garden will be held in 2022.


2015 ◽  
pp. 96-124
Author(s):  
E. G. Zibzeev ◽  
T. A. Nedovesova

The mountain systems are characterized by diverse ecological conditions (climate, geomorphological, soil, etc.). The wide spectrum of environmental conditions entails a rich diversity of plant communities growing on the small territory and determines the different flora and vegetation geneses. The uniqueness of floristic and coenotic diversities of the high-mountain vegetation of the south of Western Altai (Ivanovskiy, Prokhodnoi, and Rossypnoi Ranges) are associated with the effect of two climate-forcing factors such as the westerly humid air mass and dry warm airflow from the inner Kazakhstan regions. The paper summarizes the data on coenotic diversity (Zibzeev, 2010, 2012) and gives a syntaxonomic analysis of the high-mountain vege­tation in the Ivanovskii, Prokhodnoi, and Rossypnoi Ranges (Western Altai, Kazakhstan). The classification of plant communities was carried out using the Braun-Blanquet approach (Westhoff, van der Maarel, 1973). The relevés records were stored in the TURBOVEG database and classified by ­TWINSPAN (Hill 1979).


2009 ◽  
pp. 27-53
Author(s):  
A. Yu. Kudryavtsev

Diversity of plant communities in the nature reserve “Privolzhskaya Forest-Steppe”, Ostrovtsovsky area, is analyzed on the basis of the large-scale vegetation mapping data from 2000. The plant community classi­fication based on the Russian ecologic-phytocoenotic approach is carried out. 12 plant formations and 21 associations are distinguished according to dominant species and a combination of ecologic-phytocoenotic groups of species. A list of vegetation classification units as well as the characteristics of theshrub and woody communities are given in this paper.


2009 ◽  
pp. 3-14
Author(s):  
V. B. Golub ◽  
N. A. Grechushkina ◽  
A. N. Sorokin ◽  
L. F. Nikolaychuk

The classification of petrophytic vegetation of coastal steeps was proposed for the Northwest Cauca­sian coast of the Black Sea using the Braun-Blanquet approach. The main factors that influence the deve­lopment of vegetation in question are abrasion and denudation sea coast processes. The coastal steeps in study area are formed by carbonate flysch. The plant communities occur on rocky slopes with poorly deve­loped soil cover, fine stone chips as well as rock crevices. Nine associations and four communities without syntaxonomic rank were documented in the table and described with respect to their phyto­socio­logical affinities, ecology, and geographical location. Diagnostic species of syntaxa were established using phi-coefficient calculations of fidelity and Fisher’s exact test. In addition, the results of relevé ordination were given using the algorithm of non-metric multi­dimensional scaling (NMS) that is embedded in PC-ORD 5.0 software package.


Author(s):  
Jianping Ju ◽  
Hong Zheng ◽  
Xiaohang Xu ◽  
Zhongyuan Guo ◽  
Zhaohui Zheng ◽  
...  

AbstractAlthough convolutional neural networks have achieved success in the field of image classification, there are still challenges in the field of agricultural product quality sorting such as machine vision-based jujube defects detection. The performance of jujube defect detection mainly depends on the feature extraction and the classifier used. Due to the diversity of the jujube materials and the variability of the testing environment, the traditional method of manually extracting the features often fails to meet the requirements of practical application. In this paper, a jujube sorting model in small data sets based on convolutional neural network and transfer learning is proposed to meet the actual demand of jujube defects detection. Firstly, the original images collected from the actual jujube sorting production line were pre-processed, and the data were augmented to establish a data set of five categories of jujube defects. The original CNN model is then improved by embedding the SE module and using the triplet loss function and the center loss function to replace the softmax loss function. Finally, the depth pre-training model on the ImageNet image data set was used to conduct training on the jujube defects data set, so that the parameters of the pre-training model could fit the parameter distribution of the jujube defects image, and the parameter distribution was transferred to the jujube defects data set to complete the transfer of the model and realize the detection and classification of the jujube defects. The classification results are visualized by heatmap through the analysis of classification accuracy and confusion matrix compared with the comparison models. The experimental results show that the SE-ResNet50-CL model optimizes the fine-grained classification problem of jujube defect recognition, and the test accuracy reaches 94.15%. The model has good stability and high recognition accuracy in complex environments.


Author(s):  
Adam Kiersztyn ◽  
Pawe Karczmarek ◽  
Krystyna Kiersztyn ◽  
Witold Pedrycz

2021 ◽  
Vol 12 (2) ◽  
pp. 317-334
Author(s):  
Omar Alaqeeli ◽  
Li Xing ◽  
Xuekui Zhang

Classification tree is a widely used machine learning method. It has multiple implementations as R packages; rpart, ctree, evtree, tree and C5.0. The details of these implementations are not the same, and hence their performances differ from one application to another. We are interested in their performance in the classification of cells using the single-cell RNA-Sequencing data. In this paper, we conducted a benchmark study using 22 Single-Cell RNA-sequencing data sets. Using cross-validation, we compare packages’ prediction performances based on their Precision, Recall, F1-score, Area Under the Curve (AUC). We also compared the Complexity and Run-time of these R packages. Our study shows that rpart and evtree have the best Precision; evtree is the best in Recall, F1-score and AUC; C5.0 prefers more complex trees; tree is consistently much faster than others, although its complexity is often higher than others.


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