scholarly journals Neighbourhood-based evidence of tree diversity promotion by beech in an old-growth deciduousconiferous mixed forest (Eastern Carpathians)

2021 ◽  
Vol 64 (1) ◽  
pp. 13-30
Author(s):  
Dan Gafta ◽  
Annik Schnitzler ◽  
Déborah Closset-Kopp ◽  
Vasile Cristea
Keyword(s):  
Tree Species ◽  
Species Coexistence ◽  
Mixed Forest ◽  
Spatial Segregation ◽  
Tree Diversity ◽  
Point Pattern ◽  
Old Growth ◽  
Individual Tree ◽  
Eastern Carpathians ◽  
The Individual

Neighbourhood models are useful tools for understanding the role of positive and negative interactions in maintaining the tree species diversity in mixed forests. Under such a presumption, we aimed at testing several hypotheses concerning the mechanisms of autogenic species coexistence in an old-growth, beech-fir-spruce stand, which is part of the Slătioara forest reserve (Eastern Carpathians). Univariate/bivariate spatial point pattern analyses, the individual tree species-area relationship, the species mingling analysis and generalised linear mixed models of neighbour interference were applied on data concerning the position and allometry of all saplings and trees occurring within a 0.24 ha plot. The monospecific distribution of either beech or spruce saplings did not support the spatial segregation hypothesis. There was no evidence of conspecific negative distance dependence, as no spatial segregation was detected between the saplings and trees of any species. Within 4 m-neighbourhood, the beech saplings appeared as diversity accumulators, which might be indicative of indirect facilitation (e.g., herd protection hypothesis). At tree stage, none of the three species showed either accumulator or repeller patterns in their neighbourhood with respect to sapling species richness. Signals of positive and negative interspecific association were found in tree-sized beech (at scales of 10 to 20 m) and spruce (at scales of 4 to 17 m), respectively. The former, highly interspersed pattern is in accordance with the hypothesis of positive complementary effects, whereas the latter, poorly intermingled pattern is probably linked to the unexpected, positive neighbouring effect of spruce trees on the stem growth of their conspecific saplings. Such self-favouring process might be due to a facilitative below-ground mechanism. Conversely, the beech saplings were suppressed through interference from the neighbouring conspecific trees. The beech appears to be the key promoter of tree species coexistence in the study forest stand, in contrast to the low interspersion of spruce in the overstorey leading to lower local tree diversity.

Natural disturbance and tree species coexistence in an old-growth beech - dwarf bamboo forest, southwestern Japan

1995 ◽  
Vol 6 (6) ◽  
pp. 875-886 ◽  
Author(s):  
Shin-Ichi Yamamoto ◽  
Naoyuki Nishimura ◽  
Kiyoshi Matsui
Keyword(s):  
Tree Species ◽  
Species Coexistence ◽  
Natural Disturbance ◽  
Dwarf Bamboo ◽  
Bamboo Forest ◽  
Old Growth

scholarly journals Individual Tree Diameter and Height Growth Models for 30 Tree Species in Mixed-Species and Uneven-Aged Forests of Mexico

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 429
Author(s):  
Jaime Briseño-Reyes ◽  
José Javier Corral-Rivas ◽  
Raúl Solis-Moreno ◽  
Jaime Roberto Padilla-Martínez ◽  
Daniel José Vega-Nieva ◽  
...  
Keyword(s):  
Tree Species ◽  
Forest Ecosystems ◽  
Growth Models ◽  
Mixed Forest ◽  
Tree Height ◽  
Height Growth ◽  
Site Factors ◽  
Individual Tree ◽  
Species Specific ◽  
Total Tree

Lack of knowledge of individual tree growth in species-rich, mixed forest ecosystems impedes their sustainable management. In this study, species-specific models for predicting individual diameter at breast height (dbh) and total tree height (h) growth were developed for 30 tree species growing in mixed and uneven-aged forest stands in Durango, Mexico. Growth models were also developed for all pine, all oaks, and all other species of the genus Arbutus (strawberry trees). A database of 55,158 trees with remeasurements of dbh and h of a 5-year growth period was used to develop the models. The data were collected from 217 stem-mapped plots located in the Sierra Madre Occidental (Mexico). Weighted regression was used to remove heteroscedasticity from the species-specific dbh and h growth models using a power function of the tree size independent variables. The final models developed in the present study to predict dbh and total tree height growth included size variables, site factors, and competition variables in their formulation. The developed models fitted the data well and explained between 98 and 99% and of the observed variation of dbh, and between 77 and 98% of the observed variation of total tree height for the studied species and groups of species. The developed models can be used for estimating the individual dbh and h growth for the analyzed species and can be integrated in decision support tools for management planning in these mixed forest ecosystems.

scholarly journals Comparison of Tree Species Classifications at the Individual Tree Level by Combining ALS Data and RGB Images Using Different Algorithms

2016 ◽  
Vol 8 (12) ◽  
pp. 1034 ◽  
Author(s):  
Songqiu Deng ◽  
Masato Katoh ◽  
Xiaowei Yu ◽  
Juha Hyyppä ◽  
Tian Gao
Keyword(s):  
Tree Species ◽  
Tree Level ◽  
Individual Tree ◽  
Rgb Images ◽  
The Individual

scholarly journals Spatial distribution of four sympatric owl species in Carpathian montane forests

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Karol Šotnár ◽  
Ján Obuch ◽  
Samuel Pačenovský ◽  
Benjamín Jarčuška
Keyword(s):  
Spatial Distribution ◽  
Tree Species ◽  
Species Coexistence ◽  
Spatial Arrangement ◽  
Point Pattern Analysis ◽  
Stand Age ◽  
Point Pattern ◽  
Montane Forests ◽  
Aegolius Funereus ◽  
Coexistence Mechanisms

AbstractKnowledge about spatial distribution of owl species is important for inferring species coexistence mechanisms. In the present study, we explore spatial patterns of distribution and habitat selection of four owl species – Eurasian pygmy owl (Glaucidium passerinum), boreal owl (Aegolius funereus), tawny owl (Strix aluco) and Ural owl (Strix uralensis) – ranging in body mass from 50 g to 1300 g, with sympatric occurrence in temperate continuous montane forests in the Veľká Fatra Mts., Western Carpathians, central Slovakia. Locations of hooting owl males were surveyed between 2009–2015 in an area of 317 km2. Spatial point pattern analysis was used for analysis of owl distribution. Random patterns of owls’ spatial arrangement dominate at both intra‐ and interspecific levels within the studied area. Only intraspecific distribution of pygmy owls and interspecific distribution of Ural owls toward tawny owls exhibited positive associations. This discrepancy with other studies can be explained in terms of pygmy owls’ preference for high‐quality nest sites and/or spatial clustering in their prey distribution, and due to aggressive behaviour of dominant Ural owls toward subdominant tawny owls, respectively. Moreover, we found considerable overlap in habitat preferences between owl species, considering stand age, stand height, tree species richness, distance to open area, elevation, slope, percentage of coniferous tree species and position on hillslope, although pygmy owls were not registered in pure broadleaved stands, Ural owls were not registered in pure coniferous stands, and boreal and Ural owls were more common on slope summits and shoulders than tawny and pygmy owls. The observed patterns of spatial arrangement might suggest developed coexistence mechanisms in these owl species; differences between studies may indicate complex interactions between intra‐ and interspecific associations and habitat quality and quantity, food availability and owl species involved in those interactions on a landscape scale.

Individual tree species identification using Dense Convolutional Network (DenseNet) on multitemporal RGB images from UAV

2020 ◽  
Vol 8 (4) ◽  
pp. 310-333
Author(s):  
Sowmya Natesan ◽  
Costas Armenakis ◽  
Udayalakshmi Vepakomma
Keyword(s):  
High Resolution ◽  
Species Identification ◽  
Tree Species ◽  
Tree Canopy ◽  
Tree Level ◽  
Eastern Canada ◽  
Convolutional Network ◽  
Individual Tree ◽  
Rgb Images ◽  
The Individual

Tree species identification at the individual tree level is crucial for forest operations and management, yet its automated mapping remains challenging. Emerging technology, such as the high-resolution imagery from unmanned aerial vehicles (UAV) that is now becoming part of every forester’s surveillance kit, can potentially provide a solution to better characterize the tree canopy. To address this need, we have developed an approach based on a deep Convolutional Neural Network (CNN) to classify forest tree species at the individual tree-level that uses high-resolution RGB images acquired from a consumer-grade camera mounted on a UAV platform. This work explores the ability of the Dense Convolutional Network (DenseNet) to classify commonly available economic coniferous tree species in eastern Canada. The network was trained using multitemporal images captured under varying acquisition parameters to include seasonal, temporal, illumination, and angular variability. Validation of this model using distinct images over a mixed-wood forest in Ontario, Canada, showed over 84% classification accuracy in distinguishing five predominant species of coniferous trees. The model remains highly robust even when using images taken during different seasons and times, and with varying illumination and angles.

scholarly journals Empirical Approach for Modelling Tree Phenology in Mixed Forests Using Remote Sensing

2021 ◽  
Vol 13 (15) ◽  
pp. 3015
Author(s):  
Koffi Dodji Noumonvi ◽  
Gal Oblišar ◽  
Ana Žust ◽  
Urša Vilhar
Keyword(s):  
Remote Sensing ◽  
Plant Species ◽  
Fagus Sylvatica ◽  
Environmental Conditions ◽  
Tree Species ◽  
Land Surface ◽  
Vegetation Indices ◽  
Mixed Forest ◽  
Individual Tree ◽  
Mixed Forests

Phenological events are good indicators of the effects of climate change, since phenological phases are sensitive to changes in environmental conditions. Although several national phenological networks monitor the phenology of different plant species, direct observations can only be conducted on individual trees, which cannot be easily extended over large and continuous areas. Remote sensing has often been applied to model phenology for large areas, focusing mostly on pure forests in which it is relatively easier to match vegetation indices with ground observations. In mixed forests, phenology modelling from remote sensing is often limited to land surface phenology, which consists of an overall phenology of all tree species present in a pixel. The potential of remote sensing for modelling the phenology of individual tree species in mixed forests remains underexplored. In this study, we applied the seasonal midpoint (SM) method with MODIS GPP to model the start of season (SOS) and the end of season (EOS) of six different tree species in Slovenian mixed forests. First, substitute locations were identified for each combination of observation station and plant species based on similar environmental conditions (aspect, slope, and altitude) and tree species of interest, and used to retrieve the remote sensing information used in the SM method after fitting the best of a Gaussian and two double logistic functions to each year of GPP time series. Then, the best thresholds were identified for SOS and EOS, and the results were validated using cross-validation. The results show clearly that the usual threshold of 0.5 is not best in most cases, especially for estimating the EOS. Despite the difficulty in modelling the phenology of different tree species in a mixed forest using remote sensing, it was possible to estimate SOS and EOS with moderate errors as low as <8 days (Fagus sylvatica and Tilia sp.) and <10 days (Fagus sylvatica and Populus tremula), respectively.

scholarly journals USING UAV-BASED 3D IMAGES OF INDIVIDUAL TREE SPECIES IN DISTANCE EDUCATION IN FORESTRY

2021 ◽  
Vol XLVI-4/W5-2021 ◽  
pp. 533-537
Author(s):  
Z. Uçar ◽  
A. E. Akay
Keyword(s):  
Distance Education ◽  
Tree Species ◽  
3D Models ◽  
Field Trips ◽  
Individual Tree ◽  
3D Images ◽  
Reading Materials ◽  
Virtual Field ◽  
Technological Developments ◽  
The Individual

Abstract. Distance education has been offered for years, but the integration of technological developments and opportunities into education has recently increased its popularity and event it became an indispensable method during the Covid-19 pandemic period. In distance education, accessing all class materials such as lecture presentations, class notes, reading materials, videos, live chats or class hours, and archive records allow students (participants) to learn without being in the same environments with teachers or learners. Technology has made vast contributions to the field of education. For instance, 3D as a teaching tool for the class attracts students’ attention, makes the learning process more enjoyable, and increases participation. In particular, for the disciplines, such as forestry, earth, and environmental sciences, which require laboratory exercises, field observation, field trips, and in-situ measurements, 3D modeling has provided many benefits in distance education. It enables 3D demonstration of the individual tree species to develop a virtual field laboratory. This study focused on the data sources and techniques to generate a 3D model of the individual tree species that forestry students used for distance education. The capabilities of the method in the generation of 3D models were evaluated by using UAV-based SfM photogrammetry. The results indicated that implementing 3D images of individual tree species can be a promising method that may increase the interest, interaction and satisfaction of the students in distance education in forestry.

Base-cation Cycling by Individual Tree Species in Old-growth Forests of Upper Michigan, USA

2005 ◽  
Vol 74 (3) ◽  
pp. 357-376 ◽  
Author(s):  
Ryo Fujinuma ◽  
James Bockheim ◽  
Nick Balster
Keyword(s):  
Tree Species ◽  
Base Cation ◽  
Old Growth ◽  
Individual Tree ◽  
Old Growth Forests

scholarly journals Spatial Segregation Facilitates the Coexistence of Tree Species in Temperate Forests

Forests ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 768 ◽  
Author(s):  
Peijian Shi ◽  
Jie Gao ◽  
Zhaopeng Song ◽  
Yanhong Liu ◽  
Cang Hui
Keyword(s):  
Tree Species ◽  
Species Coexistence ◽  
Spatial Competition ◽  
Plant Competition ◽  
Spatial Segregation ◽  
Forest Community ◽  
Niche Separation ◽  
Large Spatial Scale ◽  
Chinese Pine ◽  
Management Intervention

Competition between plants has an important role during the natural succession of forest communities. Niche separation between plants can reduce such interspecific competition and enable multispecies plant to achieve coexistence, although this proposition has rarely been supported in experiments. Plant competition can be captured by spatial segregation of the competing species to avoid fierce direct conflicts for nutrients and light. We investigated a site of 400 m × 1000 m in Beijing Pine Mountain National Nature Reserve that was established for protecting Chinese pine and some rare fungi. Six dominant tree species (Fraxinus chinensis Roxb., Syringa reticulata (Blume) H. Hara var. amurensis (Rupr.) J. S. Pringle, Quercus mongolica Fisch. ex Ledeb., Armeniaca sibirica (L.) Lam., Pinus tabuliformis Carrière, and Ulmus pumila L.) were individually marked. Metrics of spatial segregation, based on the theory of spatial point process, were calculated to detect spatial competition. The corresponding type (species)-specific probabilities and the p-values from a spatially implicit test revealed significant overall spatial segregation between the six tree species. We further used the cross-type L-function to check the spatial correlation between Chinese pine and the other tree species, and detected a significant spatial repulsion relationship with four other tree species. Our study shows that each of the six dominant tree species occupies a different subarea in the landscape to effectively reduce direct spatial competition. We thus argue that patchy distributions of different tree species could be common in late forest community succession, and the coexistence of plants could be maintained over a large spatial scale. Management intervention, such as thinning the densities of dominant tree species, could be used to foster species coexistence and ensure the productivity of commercial stands.

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