scholarly journals Species Identity of Large Trees Affects the Composition and the Spatial Structure of Adjacent Trees

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1162
Author(s):  
Olga Cholewińska ◽  
Andrzej Keczyński ◽  
Barbara Kusińska ◽  
Bogdan Jaroszewicz
Keyword(s):  
Spatial Structure ◽  
Biological Diversity ◽  
Nearest Neighbor ◽  
Linear Models ◽  
Point Of View ◽  
Species Identity ◽  
Large Tree ◽  
Large Trees ◽  
Old Trees ◽  
Temperate Forest Ecosystem

Large trees are keystone structures for the functioning and maintenance of the biological diversity of wooded landscapes. Thus, we need a better understanding of large-tree–other-tree interactions and their effects on the diversity and spatial structure of the surrounding trees. We studied these interactions in the core of the Białowieża Primeval Forest—Europe’s best-preserved temperate forest ecosystem, characterized by high abundance of ancient trees. We measured diameter and bark thickness of the monumental trees of Acer platanoides L., Carpinus betulus L., Picea abies (L.) H. Karst, Quercus robur L., and Tilia cordata Mill., as well as the diameter and distance to the monumental tree of five nearest neighbor trees. The effects of the monumental tree on arrangements of the surrounding trees were studied with the help of linear models. We revealed that the species identity of a large tree had, in the case of C. betulus and T. cordata, a significant impact on the diversity of adjacent tree groupings, their distance to the central tree, and frequency of the neighboring trees. The distance between the neighbor and the large trees increased with the increasing diameter of the central tree. Our findings reinforce the call for the protection of large old trees, regardless of their species and where they grow from the geographical or ecosystem point of view.

Stability of the large tree component in treated and untreated late-seral interior ponderosa pine standsThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

2008 ◽  
Vol 38 (5) ◽  
pp. 919-923 ◽  
Author(s):  
Martin W. Ritchie ◽  
Brian M. Wing ◽  
Todd A. Hamilton
Keyword(s):  
Pinus Ponderosa ◽  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Past History ◽  
Mature Trees ◽  
Individual Tree ◽  
Large Tree ◽  
Large Trees ◽  
Tree Component ◽  
Old Trees

Ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) stands with late-seral features are found infrequently, owing to past management activities throughout western North America. Thus, management objectives often focus on maintaining existing late-seral stands. Observations over a 65 year period of stands with no past history of harvest showed substantial ingrowth in the smaller diameter classes and elevated rates of mortality among the largest mature trees in the stand. Adjacent stands, with combinations of thinning and prescribed fire, had far fewer high-risk mature trees and generally lower rates of mortality after treatment. Forecasts using individual-tree diameter growth and mortality models suggest that observed declines in these stands with remaining old trees and a dense understory will continue in the absence of any treatment. Increased vigor in thinned stands appeared to be offset by an increase in mortality of large trees when thinning was followed by prescribed fire.

scholarly journals Aggregation Site Choice by Gregarious Nymphs of the Desert Locust, Schistocerca gregaria, in the Sahara Desert of Mauritania

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 99 ◽  
Author(s):  
Koutaro Ould Maeno ◽  
Mohamed Abdallahi Ould Babah Ebbe
Keyword(s):  
Plant Community ◽  
Nearest Neighbor ◽  
Schistocerca Gregaria ◽  
Plant Size ◽  
Sahara Desert ◽  
Desert Locust ◽  
Control Approach ◽  
Large Tree ◽  
Aggregation Site ◽  
Large Trees

Animals often aggregate at certain sites during vulnerable periods such as night-roosting as an anti-predatory strategy. Some migratory gregarious animals must regularly find new night-roosting sites, but how they synchronously choose such sites is poorly understood. We examined how gregarious nymphs of the desert locust, Schistocerca gregaria Forskål (Orthoptera: Acrididae), aggregate at certain plants for night-roosting in the Sahara Desert. Migratory bands of last instar nymphs climbed trees around dusk and roosted there overnight. A spatial autocorrelation analysis of plants indicated that the larger locust groups formed at the larger plants within the local plant community. Other large groups were not formed near the large tree, but smaller groups were patchily distributed. Plant height was the primary cue used by migratory bands to choose night-roosting plants. A nearest-neighbor distance analysis showed that single conspicuous large trees with scattered smaller plants were distributed locally. This plant community structure and negative geotactic ascending behavior of gregarious nymphs may force them to concentrate at the landmark plant from all directions and afar. This plant-size-dependent roosting site choice may contribute for developing artificial trapping systems for locusts and inciting to a new environment-friendly night control approach.

scholarly journals Effect of tree species identity and related habitat parameters on understorey bryophytes – interrelationships between bryophyte, soil and tree factors in a 50-year-old experimental forest

2021 ◽  
Author(s):  
Kaja Rola ◽  
Vítězslav Plášek ◽  
Katarzyna Rożek ◽  
Szymon Zubek
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Forest Floor ◽  
Vascular Plant ◽  
Soil Parameters ◽  
Species Identity ◽  
Habitat Factors ◽  
Positive Correlations ◽  
Old Trees ◽  
Habitat Parameters

Abstract Aim Overstorey tree species influence both soil properties and microclimate conditions in the forest floor, which in turn can induce changes in ground bryophyte communities. The aim of the study was to investigate the effect of tree species identity and the most important habitat factors influencing understorey bryophytes. Methods We assessed the effect of 14 tree species and related habitat parameters, including soil parameters, vascular plant presence and light intensity on bryophytes in monospecific plots covered by nearly fifty-year-old trees in the Siemianice Experimental Forest (Poland). Results The canopy tree species determined bryophyte species richness and cover. The strongest differences were observed between plots with deciduous and coniferous trees. Soils with a more acidic pH and lower content of macronutrients supported larger bryophyte coverage. We also found a positive correlations between vascular plants and availability of light as well as bryophyte species richness. Conclusion Tree species identity and differences in habitat conditions in the forest floor lead to changes of ground bryophyte richness, cover and species composition. Consequently, the changes in the dominant tree species in the stand may result in significant repercussions on ground bryophyte communities. We indicated that the introduction of alien tree species, i.e. Quercus rubra, has an adverse effect on bryophyte communities and suggested that the selection of tree species that contribute to the community consistent with the potential natural vegetation is highly beneficial for maintaining ground bryophyte biodiversity.

Logical aspects of experimental design and analysis

2020 ◽  
pp. 142-151
Author(s):  
Валерий Иванович Хабаров
Keyword(s):  
Model Theory ◽  
Semantic Analysis ◽  
Linear Models ◽  
Intelligent System ◽  
Knowledge Bases ◽  
Object Identification ◽  
Point Of View ◽  
Applied Theory ◽  
Formal Representation ◽  
Active Object

Предложена схема формализации задач активной идентификации объекта с использованием аппарата теории моделей - современного раздела математической логики. Теория моделей позволяет погрузить предмет “планирование и анализ эксперимента” в контекст семантического анализа. Семантический анализ понимается как установление соответствия между миром и его формальным представлением. С этой точки зрения представления об исследуемом объекте выражаются в некоторой прикладной теории. Предложен вывод модели для данной теории как процесс интерпретации, в котором ключевая роль отводится “экспериментатору”. Полученные результаты могут быть использованы при проектировании архитектур интеллектуальных систем для экспериментальных исследований, для построения онтологии эксперимента, создания баз знаний Purpose. The purpose of this work is to formalize the tasks of active object identification based on the apparatus of model theory - a modern section of mathematical logic. Model theory allows putting the subject “planning and analysis of an experiment” in the context of semantic analysis. Semantic analysis is understood as establishing a correspondence between the world and its formal representation. From this point of view, the concept of the object under study is expressed in some applied theory, which allows applying formal methods of model theory to it. Methods. It is assumed that the model is derived for this theory as an interpretation process, in which the key role is assigned to the experimenter. As a research method, it is proposed to use commutative diagrams that reflect the process of interpretation and extension of communication diagrams for the so-called equipped theories of planning and analysis of experiments. Results. The properties of the proposed models are proved and examples for planning a regression experiment are presented as an illustration. It is proved that for linear models it is possible to construct a finitely axiomatization capable theory. Findings, originality. The obtained results can be used in the design of architectures for an intelligent system in experimental research, building an experiment ontology and creation of knowledge bases. These studies will allow using logical programming to implement images of the presented commutative diagrams for equipped theories as applied systems for planning and interpreting the experiment

scholarly journals Twitter sentiment analysis of the relocation of Indonesia's capital city

2020 ◽  
Vol 9 (4) ◽  
pp. 1620-1630
Author(s):  
Edi Sutoyo ◽  
Ahmad Almaarif
Keyword(s):  
Support Vector Machine ◽  
Sentiment Analysis ◽  
Nearest Neighbor ◽  
Point Of View ◽  
Capital City ◽  
Support Vector ◽  
K Nearest Neighbor ◽  
Evaluation Algorithm ◽  
The Government ◽  
The Many

Indonesia has a capital city which is one of the many big cities in the world called Jakarta. Jakarta's role in the dynamics that occur in Indonesia is very central because it functions as a political and government center, and is a business and economic center that drives the economy. Recently the discourse of the government to relocate the capital city has invited various reactions from the community. Therefore, in this study, sentiment analysis of the relocation of the capital city was carried out. The analysis was performed by doing a classification to describe the public sentiment sourced from twitter data, the data is classified into 2 classes, namely positive and negative sentiments. The algorithms used in this study include Naïve Bayes classifier, logistic regression, support vector machine, and K-nearest neighbor. The results of the performance evaluation algorithm showed that support vector machine outperformed as compared to 3 algorithms with the results of Accuracy, Precision, Recall, and F-measure are 97.72%, 96.01%, 99.18%, and 97.57%, respectively. Sentiment analysis of the discourse of relocation of the capital city is expected to provide an overview to the government of public opinion from the point of view of data coming from social media. 

Uncovering community structure in networks via hybrid clustering using cascading failure dynamics and topological metric functions

2019 ◽  
Vol 33 (29) ◽  
pp. 1950352
Author(s):  
Bo Yang ◽  
Tao Huang ◽  
Xu Li
Keyword(s):  
Community Structure ◽  
Community Detection ◽  
Nearest Neighbor ◽  
Structural Information ◽  
Point Of View ◽  
Cascading Failures ◽  
Hybrid Clustering ◽  
Mesoscale Structure ◽  
Metric Functions ◽  
Global And Local

Many networks have community structure — groups of nodes within which connections are dense but between which they are sparser. While there exists a range of algorithms for community detection in networks, most of them try to discover this important mesoscale structure from a topological point of view solely. Here we develop a hybrid clustering approach for uncovering the community structure in a network using a combination of information on local topology of the network and on the dynamics of the cascading failures. The originality of the proposed approach is that we introduce a novel fusion of the dynamic behaviors of the cascading failures and topological metric functions in the [Formula: see text]th-nearest neighbor density scheme, which integrates both the global and local structural information of a given network for community detection. The experimental results on both artificial random and real-world benchmark networks indicate the effectiveness and reliability of our approach.

Using Fuzzy Song Sets in Music Warehouses

2010 ◽  
pp. 54-83 ◽  
Author(s):  
François Deliège ◽  
Torben Bach Pedersen
Keyword(s):  
Data Structure ◽  
Data Management ◽  
Nearest Neighbor ◽  
Point Of View ◽  
Practical Implementation ◽  
Management Scenarios ◽  
Practical Solution ◽  
Similarity Space ◽  
Nearest Neighbor Searches ◽  
Song Sets

The emergence of music recommendation systems calls for the development of new data management technologies able to query vast music collections. In this chapter, the authors present a music warehouse prototype able to perform efficient nearest neighbor searches in an arbitrary song similarity space. Using fuzzy songs sets, the music warehouse offers a practical solution to three concrete musical data management scenarios: user musical preferences, user feedback, and song similarities. The authors investigate three practical approaches to tackle the storage issues of fuzzy song sets: tables, arrays, and compressed bitmaps. They confront theoretical estimates with practical implementation results and prove that, from a storage point of view, arrays and compressed bitmaps are both effective data structure solutions. With respect to speed, the authors show that operations on compressed bitmap offer a significant grain in performances for fuzzy song sets comprising a large number of songs. Finally, the authors argue that the presented results are not limited to music recommendations system but can be applied to other domains.

Large retinal ganglion cells that form independent, regular mosaics in the ranid frogs Rana esculenta and Rana pipiens

1997 ◽  
Vol 14 (6) ◽  
pp. 1109-1127 ◽  
Author(s):  
K. M. Shamim ◽  
F. Scalia ◽  
P. Tóth ◽  
J. E. Cook
Keyword(s):  
Rana Pipiens ◽  
Nearest Neighbor ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Rana Esculenta ◽  
Population Based ◽  
Inner Plexiform Layer ◽  
High Regularity ◽  
Large Trees ◽  
Cell Dimensions

AbstractPopulation-based studies of ganglion cells in retinal flatmounts have helped to reveal some of their natural types in mammals, teleost fish and, recently, the aquatic mesobatrachian frog Xenopus laevis. Here, ganglion cells of the semiterrestrial neobatrachian frogs Rana esculenta and Rana pipiens have been studied similarly. Ganglion cells with large somata and thick dendrites could again be divided into three mosaic-forming types with distinctive stratification patterns. Cell dimensions correlated inversely with density, being smallest in the visual streak. Cells of the αa mosaic (<0.2% of all ganglion cells) had the largest somata at each location (often displaced) and their trees were confined to one shallow plane within sublamina a of the inner plexiform layer. In regions of high regularity, many trees were symmetric. Elsewhere, asymmetric, irregular trees predominated and their dendrites, although sparsely branched, achieved consistent coverage by intersecting in complex ways. Cells of the αab mosaic were more numerous (≈0.7%) and had large somata, smaller (but still large) trees, and dendrites that branched extensively in two separate shallow planes in sublaminae a and b. The subtrees did not always match in symmetry, and each subtree tessellated independently with its neighbors. Cells of the αc mosaic (≈0.1%) had large, orthotopic somata and large, sparse trees (often asymmetric and irregular) close to the ganglion cell layer. Nearest-neighbor analyses and spatial correlograms confirmed that each mosaic was regular and independent. Densities, proportions, sizes, and mosaic statistics are tabulated for all three types, which are compared with types defined by size and symmetry in R. pipiens, by discriminant analysis in R. temporaria, by physiological response in both, and by mosaic analysis in Xenopus and several teleosts. The variable stratification of these otherwise similar types across species is consistent with other evidence that stratification may be determined, in part, by functional interactions.

scholarly journals Can Morphology Predict the Conservation Status of Iguanian Lizards?

2020 ◽  
Vol 60 (2) ◽  
pp. 535-548 ◽  
Author(s):  
Donald B Miles
Keyword(s):  
Morphological Traits ◽  
Biological Diversity ◽  
Linear Models ◽  
Extinction Risk ◽  
Conservation Status ◽  
Rapid Assessment ◽  
Ann Model ◽  
Functional Link ◽  
Threat Status ◽  
Risk Of Extinction

Synopsis The integrity of regional and local biological diversity is under siege as a result of multiple anthropogenic threats. The conversion of habitats, such as rain forests, into agricultural ecosystems, reduces the area available to support species populations. Rising temperatures and altered rainfall patterns lead to additional challenges for species. The ability of conservation biologists to ascertain the threats to a species requires data on changes in distribution, abundance, life history, and ecology. The International Union for the Conservation of Nature (IUCN) uses these data to appraise the extinction risk for a species. However, many species remain data deficient (DD) or unassessed. Here, I use 14 morphological traits related to locomotor function, habitat, and feeding to predict the threat status of over 400 species of lizards in the infraorder Iguania. Morphological traits are an ideal proxy for making inferences about a species’ risk of extinction. Patterns of morphological covariation have a known association with habitat use, foraging behavior, and physiological performance across multiple taxa. Results from phylogenetic general linear models revealed that limb lengths as well as head characters predicted extinction risk. In addition, I used an artificial neural network (ANN) technique to generate a classification function based on the morphological traits of species with an assigned IUCN threat status. The network approach identified eight morphological traits as predictors of extinction risk, which included head and limb characters. The best supported model had a classification accuracy of 87.4%. Moreover, the ANN model predicted &gt;18% of DD/not assessed species were at risk of extinction. The predicted assessments were supported by other sources of threat status, for example, Convention on International Trade in Endangered Species appendices. Because of the functional link between morphology, performance, and ecology, an ecomorphological approach may be a useful tool for rapid assessment of DD or poorly known species.

scholarly journals Production of highly ionized plasma by micro-dot array irradiation and its application to compact X-ray lasers

2002 ◽  
Vol 20 (1) ◽  
pp. 73-77 ◽  
Author(s):  
NAOHIRO YAMAGUCHI ◽  
CHIEMI FUJIKAWA ◽  
KAZUNOBU OKASAKA ◽  
TAMIO HARA
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Pulse Train ◽  
Production Method ◽  
Point Of View ◽  
Rapid Expansion ◽  
Laser Generation ◽  
Plasma Production ◽  
X Ray ◽  
Laser Gain

A plasma production method using the irradiation of an array of small spots has been investigated from the point of view of soft X-ray laser generation in the recombining plasma scheme pumped by a pulse-train laser. The expansion geometry of highly ionized ions produced by the micro-dot array irradiation method has been measured and compared with that by a simple line irradiation. Spatial distribution of gain coefficients of the Li-like Al ion transition lines have also been measured for both irradiation methods. Highly ionized ions were observed to spread wider in the micro-dot array irradiation method. It is expected that rapid expansion and efficient cooling are achieved in plasmas produced by the micro-dot array irradiation method, which is consistent with the experimental results on the spatial structure of the X-ray laser gain region.

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