scholarly journals Assessing the influence of climate on the growth rate of boreal tree species in northeastern Canada through long term permanent sample plot datasets

2020 ◽  
Author(s):  
Tyler Searls ◽  
Xinbiao Zhu ◽  
D.W. McKenney ◽  
Rony Mazumder ◽  
James Steenberg ◽  
...  
Keyword(s):  
Tree Growth ◽  
Tree Species ◽  
Newfoundland And Labrador ◽  
Climatic Variables ◽  
Limiting Factor ◽  
Climate Projections ◽  
Sample Plot ◽  
Permanent Sample Plot ◽  
Mixed Modelling

Climate has a considerable influence on tree growth. Forest managers benefit from the empirical study of the historic relationship between climatic variables and tree growth to support forest management frameworks which are to be applied under scenarios of climate change. Through this research, we have utilized long-term permanent sample plot records, historic climate datasets, and linear mixed modelling techniques to evaluate the historic influence of climatic variables on the growth rates of major boreal tree species in Newfoundland and Labrador, Canada. For the commercially significant spruce and fir forests of the province, we found growing degree days (GDD) to negatively correlate with tree productivity in warmer regions, such as much of Newfoundland (±1,350 GDD), but positively correlate with growth in cooler regions, such as those in Labrador (±750 GDD). With respect to precipitation, environmental moisture was not on average a limiting factor to species productivity in the province. These dynamics have implications for the productivity of the spruce-fir forests of the study area when considered alongside contemporary climate projections for the region, which generally entail both a warmer and wetter growing environment.

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.

The 2018 drought and its consequences: Investigating the resilience of different tree species based on comprehensive long-term monitoring of forest hydrology

2020 ◽  
Author(s):  
Theresa Blume ◽  
Daniel Balanzategui ◽  
Lisa Schneider ◽  
Daniel Rasche ◽  
Markus Morgner ◽  
...  
Keyword(s):  
Soil Moisture ◽  
High Resolution ◽  
Water Deficit ◽  
Tree Growth ◽  
Tree Species ◽  
Temperate Forest ◽  
Subsurface Water ◽  
Forest Stands ◽  
Northeastern Germany

<p>Many forests in Central Europe experienced unprecedented drought conditions in 2018. The exceptionally long dry period, lasting from early-summer 2018 and into the winter, was followed by another dry summer with record-breaking temperatures.   Ecohydrological consequences of extended droughts for these temperate forest systems are difficult to anticipate, and investigating the resilience of forest hydrological systems requires comprehensive and systematic long-term observations.</p><p>Monitoring at the TERENO-NE temperate forest observatory in northeastern Germany includes input characterization (throughfall and stemflow), high-resolution soil moisture observations in 14 different forest stands down to a depth of 2 m below the soil surface, shallow and deep groundwater observations, sap flow, tree water deficit and high-resolution tree growth measurements since 2012. The investigated forest stands cover the three tree species pine, oak and beech in both pure and mixed stands. This is complemented by terrestrial gravimetric measurements of total water storage changes. Steep hillslope transects allow us to investigate the impact of presence or absence of groundwater availability on tree water uptake and growth.</p><p>We find that after the unprecedented drought in 2018, which already had pronounced ecohydrological effects, the rainfall amounts over the winter 2018/19 were insufficient to refill the subsurface water storages. Dry conditions altered the growth phenology of each monitored tree species, while tree-water deficit and tree growth were negatively impacted in both years, but to varying extent. Soil moisture storage and dynamics are strongly affected and the drought caused a long-term memory effect.</p>

scholarly journals Changes in Supraglacial Lakes on George VI Ice Shelf, Antarctic Peninsula: 1973–2020

2021 ◽  
Author(s):  
Thomas James Barnes ◽  
Amber Alexandra Leeson ◽  
Malcolm McMillan ◽  
Vincent Verjans ◽  
Jeremy Carter ◽  
...  
Keyword(s):  
Historical Context ◽  
Limiting Factor ◽  
Climate Projections ◽  
Climate Data ◽  
Ice Shelf ◽  
Air Content ◽  
Supraglacial Lakes ◽  
Lake Formation ◽  
Sentinel 2

Abstract. High densities of supraglacial lakes have been associated with ice shelf instability and collapse. 2020 was a record melt year on George VI ice shelf with ~12 % of its northernmost portion being covered by lakes. We use 208 Sentinel-2 and Landsat-1-8 satellite images from the past 47 years, together with climate data and firn modelling, to assess the long-term presence of lakes on George VI, thus placing 2020 within a historical context. We find that the ~12 % lake coverage observed in 2020 is not unprecedented and similar to previous high lake years; events of similar magnitude occurred at least five times previously. Secondly, we find lake coverage is controlled by a combination of melting, accumulation, firn air content and firn build-up strong melting alone does not entail high lake coverage. Instead, while melting contributes positively to lake formation, we find accumulation to act as a limiting factor on the formation of lakes in response to melt, introducing new frozen material to the surface, thus cooling and storing meltwater. We find accumulation’s ability to limit melt to be further enhanced by its build-up, increasing available firn air content, and thus meltwater storage capacity. Our findings are supported by comparative analysis, showing years such as 1989 to have 55 % less melt, but similar lake coverage to 2020. Finally, we find that climate projections suggest future temperature increases, but steady snowfall in this region. Thus, in future there will be a greater propensity for higher lake densities on North George VI ice shelf, and associated risk of instability.

scholarly journals Modeling the long-term dynamics of tropical forests: from leaf traits to whole-tree growth patterns

2020 ◽  
Author(s):  
Gunnar Petter ◽  
Holger Kreft ◽  
Yongzhi Ong ◽  
Gerhard Zotz ◽  
Juliano Sarmento Cabral
Keyword(s):  
Tropical Forests ◽  
Functional Traits ◽  
Tree Growth ◽  
Tree Species ◽  
Leaf Traits ◽  
Forest Stand ◽  
Growth Patterns ◽  
Leaf Economic Spectrum ◽  
Individual Trees

AbstractTropical forests are the most diverse terrestrial ecosystems and home to numerous tree species with diverse ecological strategies competing for resources in space and time. Functional traits influence the ecophysiological performance of tree species, yet the relationship between traits and emergent long-term growth pattern is poorly understood. Here, we present a novel 3D forest stand model in which growth patterns of individual trees and forest stands are emergent properties of leaf traits. Individual trees are simulated as 3D functional-structural tree models (FSTMs), considering branches up to the second order and leaf dynamics at a resolution of one m3. Each species is characterized by a set of leaf traits that corresponds to a specific position on the leaf economic spectrum and determines light-driven carbon assimilation, respiration and mortality rates. Applying principles of the pipe model theory, these leaf scale-processes are coupled with within-tree carbon allocation, i.e., 3D tree growth emerges from low-level processes. By integrating these FSTMs into a dynamic forest stand model, we go beyond modern stand models to integrate structurally-detailed internal physiological processes with interspecific competition, and interactions with the environment in diverse tree communities. For model calibration and validation, we simultaneously compared a large number of emergent patterns at both the tree and forest levels in a pattern-oriented modeling framework. At the tree level, varying specific leaf area and correlated leaf traits determined the maximum height and age of a tree, as well as its size-dependent growth rate and shade tolerance. Trait variations along the leaf economic spectrum led to a continuous transition from fast-growing, short-lived and shade-intolerant to slow-growing, long-lived and shade-tolerant trees. These emerging patterns resembled well-known functional tree types, indicating a fundamental impact of leaf traits on long-term growth patterns. At the forest level, a large number of patterns taken from lowland Neotropical forests were reproduced, indicating that our forest model simulates structurally realistic forests over long time spans. Our ecophysiological approach improves the understanding of how leaf level processes scale up to the tree and the stand level, and facilitates the development of next-generation forest models for species-rich forests in which tree performance emerges directly from functional traits.

scholarly journals Tropical tree growth sensitivity to climate is driven by species intrinsic growth rate and leaf traits

2021 ◽  
Author(s):  
David Bauman ◽  
Claire Fortunel ◽  
Lucas A. Cernusak ◽  
Lisa P. Bentley ◽  
Sean M. McMahon ◽  
...  
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Tree Species ◽  
Forest Dynamics ◽  
Species Traits ◽  
Growth Responses ◽  
Growth Data ◽  
Short Term ◽  
Evaporative Demand

A better understanding of how climate affects growth in tree species is essential for improved predictions of forest dynamics under climate change. Long-term climate averages (mean climate) and short-term deviations from these averages (anomalies) both influence tree growth, but the rarity of long-term data integrating climatic gradients with tree censuses has so far limited our understanding of their respective role, especially in tropical systems. Here, we combined 49 years of growth data for 509 tree species across 23 tropical rainforest plots along a climatic gradient to examine how tree growth responds to both climate means and anomalies, and how species functional traits mediate these tree growth responses to climate. We showed that short-term, anomalous increases in atmospheric evaporative demand and solar radiation consistently reduced tree growth. Drier forests and fast-growing species were more sensitive to water stress anomalies. In addition, species traits related to water use and photosynthesis partly explained differences in growth sensitivity to both long-term and short-term climate variations. Our study demonstrates that both climate means and anomalies shape tree growth in tropical forests, and that species traits can be leveraged to understand these demographic responses to climate change, offering a promising way forward to forecast tropical forest dynamics under different climate trajectories.

scholarly journals Tree demography in an undisturbed Dipterocarp permanent sample plot at Uppangala, Western Ghats of India

Ecology ◽  
2011 ◽  
Vol 92 (6) ◽  
pp. 1376-1376 ◽  
Author(s):  
Raphaël Pélissier ◽  
Jean-Pierre Pascal ◽  
N. Ayyappan ◽  
B. R. Ramesh ◽  
S. Aravajy ◽  
...  
Keyword(s):  
Western Ghats ◽  
Sample Plot ◽  
Tree Demography ◽  
Western Ghats Of India ◽  
Permanent Sample Plot

Development of Forest Shelterbelts Considering Statistical Forecasts Modelling of Local Weather

2021 ◽  
Vol 18 (1) ◽  
pp. 7-14
Author(s):  
Irina Volkova ◽  
Kseniia Pitulko ◽  
Anzhelika Sergeeva ◽  
Saida Pshidatok
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Structural Changes ◽  
Moscow Oblast ◽  
Phytopathogenic Bacteria ◽  
Heat Damage ◽  
Class 1 ◽  
Local Weather ◽  
Species Class

This work aims to study the effect of high temperatures and phytopathogenic bacteria on different types of trees in the forest shelterbelts. Therefore, in 2018, 17 tree species were studied from 50 sample sites in the Moscow oblast (Russia). Leaf scorching, diseases caused by phytopathogenic bacteria, and heat damage to the crowns were examined in 5224 tree species. Based on the degree of crown damage, the studied tree species were divided into four classes. It was found that the heat damage to tree crowns was identical between the three sampling aspects (correlation coefficient 0.99). The plant species composition must be considered when developing forest shelterbelts. A long-term forecast on structural changes of planted areas is possible, considering the species composition and climatic characteristics of the region. Class 5 includes only chestnut; class 4 includes three species; class 3 is represented by seven species. Class 2, includes six species, and is the most suitable in developing forest plantations. No tree species in class 1 were found (trees with no damage). There is a connection between pathologies and heat injuries in trees from classes 4 to 5 (correlation 0.89).

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