scholarly journals Nothing else matters? Tree characteristics have more effects than biogeoclimatic context on microhabitat diversity and occurrence: a nationwide analysis

2018 ◽  
Author(s):  
Yoan Paillet ◽  
Nicolas Debaive ◽  
Frédéric Archaux ◽  
Eugénie Cateau ◽  
Olivier Gilg ◽  
...  
Keyword(s):  
Tree Species ◽  
Large Scale ◽  
Wood Decay ◽  
Life Cycles ◽  
Structural Elements ◽  
Biodiversity Indicators ◽  
Forest Reserves ◽  
Tree Diameter ◽  
Dead Trees ◽  
Large Living

AbstractManaging forests to preserve biodiversity requires a good knowledge not only of the factors driving its dynamics but also of the structural elements that actually support biodiversity. Tree-related microhabitats (cavities, cracks, conks of fungi) are tree-borne features that are reputed to support specific biodiversity for at least a part of species’ life cycles. While several studies have analysed the drivers of microhabitats number and occurrence at the tree scale, they remain limited to a few tree species located in relatively narrow biogeographical ranges. We used a nationwide database of forest reserves where microhabitats were inventoried on more than 22,000 trees. We analysed the effect of tree diameter and living status (alive or dead) on microhabitat number and occurrence per tree, taking into account biogeoclimatic variables and tree genus.We confirmed that larger trees and dead trees bore more microhabitats than their smaller or living counterparts did; we extended these results to a wider range of tree genera and ecological conditions. Contrary to expectations, the total number of microhabitat types per tree barely varied with tree genus – though we did find slightly higher accumulation levels for broadleaves than for conifers – nor did it vary with elevation or soil pH. We observed the same results for the occurrence of individual microhabitat types. However, accumulation levels with diameter and occurrence on dead trees were higher for microhabitats linked with wood decay processes (e.g. dead branches or woodpecker feeding holes) than for other, epixylic, microhabitats such as epiphytes (ivy, mosses and lichens).Promoting large living and dead trees of several tree species may be an interesting, and nearly universal, way to favour microhabitats and enhance the substrates needed to support specific biodiversity. In addition, a better understanding of microhabitat drivers and dynamics at the tree scale may help to better define their role as biodiversity indicators for large-scale monitoring.

scholarly journals Large-Scale Mapping of Tree Species and Dead Trees in Šumava National Park and Bavarian Forest National Park Using Lidar and Multispectral Imagery

2020 ◽  
Vol 12 (4) ◽  
pp. 661 ◽  
Author(s):  
Peter Krzystek ◽  
Alla Serebryanyk ◽  
Claudius Schnörr ◽  
Jaroslav Červenka ◽  
Marco Heurich
Keyword(s):  
Tree Species ◽  
National Park ◽  
Large Scale ◽  
Dead Wood ◽  
Multispectral Imagery ◽  
Normalized Cut ◽  
Dead Trees ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
Bavarian Forest

Knowledge of forest structures—and of dead wood in particular—is fundamental to understanding, managing, and preserving the biodiversity of our forests. Lidar is a valuable technology for the area-wide mapping of trees in 3D because of its capability to penetrate vegetation. In essence, this technique enables the detection of single trees and their properties in all forest layers. This paper highlights a successful mapping of tree species—subdivided into conifers and broadleaf trees—and standing dead wood in a large forest 924 km2 in size. As a novelty, we calibrate the critical stopping criterion of the tree segmentation based on a normalized cut with regard to coniferous and broadleaf trees. The experiments were conducted in Šumava National Park and Bavarian Forest National Park. For both parks, lidar data were acquired at a point density of 55 points/m2. Aerial multispectral imagery was captured for Šumava National Park at a ground sample distance (GSD) of 17 cm and for Bavarian Forest National Park at 9.5 cm GSD. Classification of the two tree groups and standing dead wood—located in areas of pest infestation—is based on a diverse set of features (geometric, intensity-based, 3D shape contexts, multispectral-based) and well-known classifiers (Random forest and logistic regression). We show that the effect of under- and oversegmentation can be reduced by the modified normalized cut segmentation, thereby improving the precision by 13%. Conifers, broadleaf trees, and standing dead trees are classified with overall accuracies better than 90%. All in all, this experiment demonstrates the feasibility of large-scale and high-accuracy mapping of single conifers, broadleaf trees, and standing dead trees using lidar and aerial imagery.

Multiple-source Record Linkage in a Rural Industrial Community, 1680–1820

1994 ◽  
Vol 6 (3) ◽  
pp. 133-142 ◽  
Author(s):  
Steve King
Keyword(s):  
Early Modern ◽  
Large Scale ◽  
Social Economic ◽  
Life Cycles ◽  
Multiple Source ◽  
Demographic Analysis ◽  
Ordinary People ◽  
Industrial Community ◽  
The Social ◽  
Broad Outline

Re-creating the social, economic and demographic life-cycles of ordinary people is one way in which historians might engage with the complex continuities and changes which underlay the development of early modern communities. Little, however, has been written on the ways in which historians might deploy computers, rather than card indexes, to the task of identifying such life cycles from the jumble of the sources generated by local and national administration. This article suggests that multiple-source linkage is central to historical and demographic analysis, and reviews, in broad outline, some of the procedures adopted in a study which aims at large scale life cycle reconstruction.

scholarly journals Classification of Tree Species as Well as Standing Dead Trees Using Triple Wavelength ALS in a Temperate Forest

2019 ◽  
Vol 11 (22) ◽  
pp. 2614 ◽  
Author(s):  
Nina Amiri ◽  
Peter Krzystek ◽  
Marco Heurich ◽  
Andrew Skidmore
Keyword(s):  
Tree Species ◽  
Feature Selection Method ◽  
Silver Fir ◽  
Maximum Point ◽  
Individual Tree ◽  
Dead Trees ◽  
Multi Wavelength ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
532 Nm

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.

scholarly journals Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 458
Author(s):  
Haiyan Deng ◽  
Linlin Shen ◽  
Jiaqi Yang ◽  
Xiaoyong Mo
Keyword(s):  
Tree Species ◽  
Forest Restoration ◽  
Large Scale ◽  
Stand Structure ◽  
Pinus Elliottii ◽  
Stem Form ◽  
Tree Species Composition ◽  
Eucalyptus Plantation ◽  
Mixed Plantation ◽  
Preservation Rate

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.

scholarly journals Co-occurrences of tropical trees in eastern South America: disentangling abiotic and biotic forces

Plant Ecology ◽  
2021 ◽  
Author(s):  
Emma-Liina Marjakangas ◽  
Otso Ovaskainen ◽  
Nerea Abrego ◽  
Vidar Grøtan ◽  
Alexandre A. de Oliveira ◽  
...  
Keyword(s):  
South America ◽  
Tree Species ◽  
Large Scale ◽  
Environmental Filtering ◽  
Limiting Similarity ◽  
Phylogenetic Relatedness ◽  
Biogeographical Regions ◽  
Dependent Processes ◽  
Occurrence Of Species

AbstractSpecies co-occurrences in local communities can arise independent or dependent on species’ niches. However, the role of niche-dependent processes has not been thoroughly deciphered when generalized to biogeographical scales, probably due to combined shortcomings of data and methodology. Here, we explored the influence of environmental filtering and limiting similarity, as well as biogeographical processes that relate to the assembly of species’ communities and co-occurrences. We modelled jointly the occurrences and co-occurrences of 1016 tropical tree species with abundance data from inventories of 574 localities in eastern South America. We estimated species co-occurrences as raw and residual associations with models that excluded and included the environmental effects on the species’ co-occurrences, respectively. Raw associations indicate co-occurrence of species, whereas residual associations indicate co-occurrence of species after accounting for shared responses to environment. Generally, the influence of environmental filtering exceeded that of limiting similarity in shaping species’ co-occurrences. The number of raw associations was generally higher than that of the residual associations due to the shared responses of tree species to the environmental covariates. Contrary to what was expected from assuming limiting similarity, phylogenetic relatedness or functional similarity did not limit tree co-occurrences. The proportions of positive and negative residual associations varied greatly across the study area, and we found a significant tendency of some biogeographical regions having higher proportions of negative associations between them, suggesting that large-scale biogeographical processes limit the establishment of trees and consequently their co-occurrences.

Projects Selection and Evaluation Tools for the of Non-Conventional Materials and Technologies (NOCMATS)

2012 ◽  
Vol 517 ◽  
pp. 13-19 ◽  
Author(s):  
P. Ohayon ◽  
Khosrow Ghavami
Keyword(s):  
Large Scale ◽  
Evaluation Criteria ◽  
Second World War ◽  
Structural Elements ◽  
Industrialized Countries ◽  
Governmental Agencies ◽  
Vegetable Fibers ◽  
Private Organizations ◽  
The Social ◽  
Second World

The results of many successfully realized Research and Development (R&D) concerned with non-conventional materials and technologies (NOCMAT) in developing countries including Brazil have not been used in large scale in practice. This is due to the lack of selection and evaluation criteria and concepts from planning and designing to implementation programs by governmental agencies and private organizations concerned with the newly developed sustainable materials and technologies. The problems of selecting and evaluating R&D innovation outputs and impacts for construction are complex and need scientific and systematic studies in order to avoid the social and environmental mistakes occurred in industrialized countries after the Second World War. This paper presents a logical framework for the implementation of pertinent indicators to be used as a tool in R&D of NOCMAT projects selection and evaluation concerned with materials, structural elements and technologies of bamboo and composites reinforced with vegetable fibers. Indicators, related to the efficiency, effectiveness, impact, relevance and sustainability of such projects are considered and discussed.

Guidelines for choosing volume equations in the presence of measurement error in height

2000 ◽  
Vol 30 (2) ◽  
pp. 306-310 ◽  
Author(s):  
M S Williams ◽  
H T Schreuder
Keyword(s):  
Measurement Error ◽  
Tree Species ◽  
Measurement Errors ◽  
Tree Diameter ◽  
Total Height ◽  
Volume Equations

Assuming volume equations with multiplicative errors, we derive simple conditions for determining when measurement error in total height is large enough that only using tree diameter, rather than both diameter and height, is more reliable for predicting tree volumes. Based on data for different tree species of excurrent form, we conclude that measurement errors up to ±40% of the true height can be tolerated before inclusion of estimated height in volume prediction is no longer warranted.

Ecological processes maintaining differential tree species distributions in an Australian subtropical rain forest: implications for models of species coexistence

2000 ◽  
Vol 16 (3) ◽  
pp. 387-415 ◽  
Author(s):  
Igor Debski ◽  
David F. R. P. Burslem ◽  
David Lamb
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Rain Forest ◽  
Large Scale ◽  
Species Coexistence ◽  
Common Species ◽  
Size Class ◽  
Differential Mortality ◽  
Mixed Composition ◽  
Large Scale Disturbance

All stems ≥ 1 cm dbh were measured, tagged, mapped and identified on a 1-ha plot of rain forest at Gambubal State Forest, south-east Queensland, Australia. The spatial patterns and size class distributions of 11 common tree species on the plot were assessed to search for mechanisms determining their distribution and abundance. The forest was species-poor in comparison to many lowland tropical forests and the common species are therefore present at relatively high densities. Despite this, only limited evidence was found for the operation of density-dependent processes at Gambubal. Daphnandra micrantha saplings were clumped towards randomly spaced adults, indicating a shift of distribution over time caused by differential mortality of saplings in these adult associated clumps. Ordination of the species composition in 25-m × 25-m subplots revealed vegetation gradients at that scale, which corresponded to slope across the plot. Adult basal area was dominated by a few large individuals of Sloanea woollsii but the comparative size class distributions and replacement probabilities of the 11 common species suggest that the forest will undergo a transition to a more mixed composition if current conditions persist. The current cohort of large S. woollsii individuals probably established after a large-scale disturbance event and the forest has not attained an equilibrium species composition.

A Model of Seawater Structure Near the West Coast of Vancouver Island, British Columbia

1963 ◽  
Vol 20 (4) ◽  
pp. 939-967 ◽  
Author(s):  
Robert K. Lane
Keyword(s):  
British Columbia ◽  
West Coast ◽  
Large Scale ◽  
Coastal Region ◽  
Vancouver Island ◽  
Structural Elements ◽  
The West ◽  
Characteristic Structure ◽  
Oceanographic Data ◽  
Vertical Sections

Oceanographic data collected in a line of stations extending seaward of the west coast of Vancouver Island, British Columbia, were reviewed and analyzed. On the basis of these data and the large-scale meteorological processes of wind, insolation, and precipitation, the characteristic structure of temperature and salinity in the coastal region was denned in five temporal stages throughout the year. These stages are presented as vertical sections along the line with characteristic ranges of values to be found in each of the structural elements.

scholarly journals An assessment of the population status of the threatened medicinal plant Illicium griffithii Hook.f. & Thomson in West Kameng District of Arunachal Pradesh, India

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tashi Dorjee Bapu ◽  
Gibji Nimasow
Keyword(s):  
Medicinal Plant ◽  
Large Scale ◽  
Arunachal Pradesh ◽  
Mature Trees ◽  
Regeneration Rate ◽  
Dead Trees ◽  
Threatened Medicinal Plant ◽  
The Family ◽  
Proper Training ◽  
Large Scale Cultivation

Illicium griffithii Hook.f. & Thomson, a medicinal plant of the family Schisandraceae, is an Endangered species listed by the IUCN.  A decline in population of this plant due to climate change as well as increasing human influences on the natural resources has been a matter of great concern among the researchers.  In order to estimate the existing population of this plant, a field-based study employing linear transect method was conducted in four phases, May–June 2017, May–June 2018, April–May 2019, October–November 2019 covering an area of 700km² (approx.) in West Kameng District of Arunachal Pradesh that lies within the Himalayan biodiversity hotspot.  The study recorded 3,044 live individuals of I. griffithii including 1,372 seedlings, 1,358 saplings, and only 314 mature trees.  Additionally, 126 dead trees were also recorded.  The study confirmed that the plant has a good regeneration rate but with a poor survival rate of saplings.  Besides, large-scale collection of its fruits for trade and anthropogenic disturbances in the study area appears to be the major threat to its existing population.  Therefore, proper training of the local people on large-scale cultivation of this plant together with awareness towards judicious harvesting of fruits from the wild may be the significant approach to conservation. 

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