scholarly journals Forest migration outpaces tree species range shift across North America

2021 ◽  
Author(s):  
Akane Abbasi ◽  
Christopher Woodall ◽  
Javier Gamarra ◽  
Thomas Ochuodho ◽  
Sergio de-Miguel ◽  
...  
Keyword(s):  
North America ◽  
Tree Species ◽  
Global Environmental Change ◽  
Species Abundance ◽  
Range Shift ◽  
New Paradigm ◽  
Mean Velocity ◽  
Individual Tree ◽  
Migration Patterns ◽  
Geographic Ranges

Abstract Mounting evidence suggests that geographic ranges of tree species worldwide are shifting under global environmental change, but little is known about forest migration—the shift in the geographic ranges of forest types—and how it differs from individual tree species migration. Here, based on in situ records of more than 9 million trees from 596,282 sample plots, we quantified and compared the migration patterns of forests and tree species across North America between 1970 and 2019. On average, forests migrated at a mean velocity of 205.2 km per decade, which is twice as fast as species-level migration (95.6 km per decade), and 12 times faster than the average of previous estimates (16.3 km per decade). Our findings suggest that as subtle perturbations in species abundance can aggregate to change an entire forest from one type to another, failing to see the forest for the trees may result in a gross underestimation of the impacts of global change on forest ecosystem functioning and services. With the first forest classification and quantification of forest migration patterns at a continental level, this study provides an urgently needed scientific basis for a new paradigm of adaptive forest management and conservation under a rapid forest migration.

scholarly journals Role of Anthropogenic drivers in altering the forest community structure in a prime tiger habitat in central India

2021 ◽  
Author(s):  
Soumya Dasgupta ◽  
Tapajit Bhattacharya ◽  
Prafulla Bhamburkar ◽  
Rahul Kaul
Keyword(s):  
Plant Community ◽  
Tree Species ◽  
Deciduous Forest ◽  
Species Abundance ◽  
Central India ◽  
Forest Community ◽  
Anthropogenic Factors ◽  
Importance Value Index ◽  
Forest Patches ◽  
Individual Tree

Tropical forests are complex systems with heterogenous community assemblages often threatened under conservation conflicts. Herbivory and disturbances affect the diversity and species assemblages within forest patches having different disturbance regimes. We studied the change in plant community composition and structure under a disturbance gradient in the tropical dry deciduous forest of the corridor area between Nagzira-Navegaon Tiger reserve of central India. We tested the hypothesis that the plant community will change along the proximity gradient from the human settlement depending on the anthropogenic stress. We sampled 183 nested quadrat plots to collect data on species abundance and various disturbance parameters. Density, diversity, and Importance Value Index were calculated from the collected data on species abundance and girth at breast height (GBH) of individual tree species. We did multivariate analysis to assess the changes in species assemblage along the disturbance gradients. We found 76% dissimilarity between the plant communities in the three disturbance gradients from near to far from the villages perpetrated by the difference in mean abundance of species like Tectona grandis, Terminalia sp, and Largerstroemia parviflora. The anthropogenic factors significantly influence the density and diversity of tree species and regeneration classes. We found the abundance of regeneration class increased along the distance from the villages. The study intensifies the need for proper management and conservative approach to preserve the minimum diversity of the forest patches for its structural and functional contiguity as a corridor in the central India's highly susceptible and intricate corridor framework.

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 Urbanization pressures alter tree rhizosphere microbiomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carl L. Rosier ◽  
Shawn W. Polson ◽  
Vincent D’Amico ◽  
Jinjun Kan ◽  
Tara L. E. Trammell
Keyword(s):  
Organic Matter ◽  
Relative Abundance ◽  
Tree Species ◽  
High Throughput Sequencing ◽  
Regional Climate ◽  
Keystone Species ◽  
Fagus Grandifolia ◽  
Yellow Poplar ◽  
Individual Tree ◽  
Structural Formation

AbstractThe soil microbial community (SMC) provides critical ecosystem services including organic matter decomposition, soil structural formation, and nutrient cycling. Studies suggest plants, specifically trees, act as soil keystone species controlling SMC structure via multiple mechanisms (e.g., litter chemistry, root exudates, and canopy alteration of precipitation). Tree influence on SMC is shaped by local/regional climate effects on forested environments and the connection of forests to surrounding landscapes (e.g., urbanization). Urban soils offer an ideal analog to assess the influence of environmental conditions versus plant species-specific controls on SMC. We used next generation high throughput sequencing to characterize the SMC of specific tree species (Fagus grandifolia [beech] vs Liriodendron tulipifera [yellow poplar]) across an urban–rural gradient. Results indicate SMC dissimilarity within rural forests suggests the SMC is unique to individual tree species. However, greater urbanization pressure increased SMC similarity between tree species. Relative abundance, species richness, and evenness suggest that increases in similarity within urban forests is not the result of biodiversity loss, but rather due to greater overlap of shared taxa. Evaluation of soil chemistry across the rural–urban gradient indicate pH, Ca+, and organic matter are largely responsible for driving relative abundance of specific SMC members.

Defining the Center—Finding the Boundaries: The Challenge of Re-Visioning the Church in North America for the Twenty-First Century

1994 ◽  
Vol 22 (3) ◽  
pp. 317-337
Author(s):  
Craig Van Gelder
Keyword(s):  
North America ◽  
North American ◽  
American Culture ◽  
First Century ◽  
New Paradigm ◽  
Twenty First Century ◽  
Mission Field ◽  
The Church

It is becoming increasingly clear that we are experiencing a shift in North American culture that requires the church to think of North America as mission field. The thesis of this article is that the church will need to develop a new paradigm of mission to accomplish this. This article identifies 18 issues which such a paradigm of mission will need to address. These issues are discussed in terms of three aspects: (1) the context in which we live, (2) the gospel we seek to proclaim, and (3) the church which seeks to proclaim this gospel.

scholarly journals Long-Term Projections of the Natural Expansion of the Pine Wood Nematode in the Iberian Peninsula

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 849
Author(s):  
Begoña de la Fuente ◽  
Santiago Saura
Keyword(s):  
Iberian Peninsula ◽  
Tree Species ◽  
Average Rate ◽  
Limiting Factor ◽  
Pine Wood Nematode ◽  
Individual Tree ◽  
Pine Wood ◽  
Pine Tree ◽  
Informative Content

The invasive pine wood nematode (PWN), Bursaphelenchus xylophilus, causal agent of pine wilt disease, was first reported in Europe, near Lisbon, in 1999, and has since then spread to most of Portugal. We here modelled the spatiotemporal patterns of future PNW natural spread in the Iberian Peninsula, as dispersed by the vector beetle Monochamus galloprovincialis, using a process-based and previously validated network model. We improved the accuracy, informative content, forecasted period and spatial drivers considered in previous modelling efforts for the PWN in Southern Europe. We considered the distribution and different susceptibility to the PWN of individual pine tree species and the effect of climate change projections on environmental suitability for PWN spread, as we modelled the PWN expansion dynamics over the long term (>100 years). We found that, in the absence of effective containment measures, the PWN will spread naturally to the entire Iberian Peninsula, including the Pyrenees, where it would find a gateway for spread into France. The PWN spread will be relatively gradual, with an average rate of 0.83% of the total current Iberian pine forest area infected yearly. Climate was not found to be an important limiting factor for long-term PWN spread, because (i) there is ample availability of alternative pathways for PWN dispersal through areas that are already suitable for the PWN in the current climatic conditions; and (ii) future temperatures will make most of the Iberian Peninsula suitable for the PWN before the end of this century. Unlike climate, the susceptibility of different pine tree species to the PWN was a strong determinant of PWN expansion through Spain. This finding highlights the importance of accounting for individual tree species data and of additional research on species-specific susceptibility for more accurate modelling of PWN spread and guidance of related containment efforts.

Geographic patterns of genetic diversity in North American trees: a continent-wide analysis

2021 ◽  
Author(s):  
Andrew V. Gougherty
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
North America ◽  
North American ◽  
Tree Species ◽  
Geographic Patterns ◽  
Study Characteristics ◽  
Dispersal Traits ◽  
The Last Glacial Maximum ◽  
The Last Glacial

In the northern hemisphere, many species have been reported to have greater genetic diversity in southern populations than northern populations - ostensibly due to migration northward following the last glacial maximum (LGM). The generality of this pattern, while well-established for some taxa, remains unclear for North American trees. To address this issue, I collected published population genetics data for 73 North American tree species, and tested whether genetic diversity was associated with latitude or longitude and whether geographic trends were associated with dispersal traits, range or study characteristics. I found there were no general geographic patterns in genetic diversity, and the strength of the geographic gradients were not associated with any species or study characteristics. Species in the northern and western regions of North America tended to have more species with genetic diversity that declined with latitude, but most species had no significant trend. This work shows that North American trees have complex, individualistic, patterns of genetic diversity that may negate explanation by any particular dispersal trait or range characteristic.

scholarly journals Individual Tree Species Classification by Illuminated—Shaded Area Separation

2009 ◽  
Vol 2 (1) ◽  
pp. 19-35 ◽  
Author(s):  
Eetu Puttonen ◽  
Paula Litkey ◽  
Juha Hyyppä
Keyword(s):  
Tree Species ◽  
Species Classification ◽  
Individual Tree ◽  
Tree Species Classification

scholarly journals Effect of disturbance on plant species abundance and density distribution in tropical forest of Sunsari district, Eastern Nepal

2016 ◽  
Vol 6 (1) ◽  
pp. 1-12
Author(s):  
Tilak Prasad Gautam ◽  
Tej Narayan Mandal
Keyword(s):  
Carbon Sequestration ◽  
Species Composition ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Tree Species ◽  
Forest Disturbance ◽  
Species Abundance ◽  
Forest Degradation ◽  
Tree Density ◽  
Shrub Species

The disappearance of global tropical forests due to deforestation and forest degradation has reduced the biodiversity and carbon sequestration capacity. In these contexts, present study was carried out to understand the species composition and density in the undisturbed and disturbed stands of moist tropical forest located in Sunsari district of eastern Nepal. Study revealed that the forest disturbance has reduced the number of tree species by 33% and tree density by 50%. In contrary, both number and density of herb and shrub species have increased with forest disturbance.

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