scholarly journals Climate warming predispose sessile oak forests to drought-induced tree mortality regardless of management legacies

2021 ◽  
Vol 491 ◽  
pp. 119097
Author(s):  
Any Mary Petritan ◽  
Ion Catalin Petritan ◽  
Andrea Hevia ◽  
Helge Walentowski ◽  
Olivier Bouriaud ◽  
...  
2019 ◽  
Vol 12 (5) ◽  
pp. 894-906
Author(s):  
Jordi Bou ◽  
Lluís Vilar

AbstractAimsOur aims were 3-fold: (i) to determine whether global change has altered the composition and structure of the plant community found in the sessile oak forests on the NE Iberian Peninsula over the last decades, (ii) to establish whether the decline in forest exploitation activities that has taken place since the mid-20th century has had any effect on the forests and (iii) to ascertain whether there is any evidence of impact from climate warming.MethodsWe assess changes in the plant community by comparing a current survey of sessile oak forest with a historical data set obtained from previous regional studies dating from 1962 to 1977. We analyse the regional changes in the community in terms of biodiversity variables, species composition and plant traits. Furthermore, plants traits such as plant life forms and chorological groups are used to discern any effects from land-use changes and climate warming on the plant community.Important FindingsThere has been a loss of diversity in the community and, in the hottest region, there is also a loss of species richness. The composition of the community suggests that, although significant changes have taken place over recent decades, these changes differ between regions as a result of the low impact global change has had in the western regions. For instance, while the tree canopy cover in the western sessile oak forests remains stable, the eastern sessile oak forests are still recovering from the former exploitation that led to a loss of their rich and abundant herbaceous stratum. In fact, the recovery process in the Catalan Pre-Coastal Range has constituted an increase in the Euro-Siberian plants typical to this community. Moreover, in the eastern forests, there is evidence that climate warming has impacted the thermophilization of the sessile oak forests found on the Coastal Range.


2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Imre Berki ◽  
Ervin Rasztovits ◽  
Norbert Móricz ◽  
László Kolozs ◽  
◽  
...  

2020 ◽  
Vol 21 (2) ◽  
pp. 71-82
Author(s):  
Roumen Petrin

The height-diameter curves of natural even-aged Hungarian oak, sessile oak and Turkey oak forests in the regions of Staro Oryahovo, Sherba, Tsonevo and Aytos Forestry Districts have been studied. In order to explore the shape of the curves and, in particular, their steepness, the steepness index SI of Douhovnikov (“the method of natural indicators”) was applied. The curves were divided into three groups according to it: flat curves, medium steep curves and steep curves. Both the traditional height-diameter curves and the corresponding relative curves of Tyurin were studied. Consideration of the traditional height-diameter curves gives a certain ground for investigating to-gether the height-diameter curves of Hungarian oak and sessile oak, disregarding the tree species. This inference was confirmed by comparing the relative height-diameter curves for Hungarian oak, sessile oak and Turkey oak with Tyurin’s uniform curve of relative heights. For these comparisons we used the Willcoxon test. A statistically significant great proximity in their shapes was found. As a uniform average curve of relative heights has been established for all tree species, this proximity indicates a possibility of creating a single fan of height-diameter curves for high Hungarian, sessile and Turkey oak.


2013 ◽  
pp. 27-55
Author(s):  
Rade Cvjeticanin ◽  
Olivera Kosanin ◽  
Milun Krstic ◽  
Marko Perovic ◽  
Marijana Novakovic-Vukovic

This research was carried out in natural stands of sessile oak (Quercus petraea agg. Ehrendorfer 1967) on Miroc mountain. Three comunities were investigated: Pure sessile oak forest (Quercetum montanum Cer. et Jov. 1953. s.l.), sessile oak-common hornbeam forest (Querco-Carpinetum moesiacum Rud. 1949. s.l.) and sessile oak-balkan beech forest (Querco-Fagetum Glis. 1971). Pure sessile oak forests are found on the following soils: dystric ranker and acid cambic soil on sandstone, dystric ranker and acid cambisols on phyllite, and acid cambic soil on schists. Sessile oak-hornbeam forests grow on sandstone, granite and schists. Sessile oak-beech forests are found on acid cambisol on phyllite and sandstone conglomerate. Various ecological conditions (exposition, slope, altitude, soil types and bedrock) on Mt Miroc caused the occurence of diverse sessile oak forest communities, while different states of these forest stands resulted from the implementation of management measures.


2011 ◽  
pp. 97-108 ◽  
Author(s):  
Milan Knezevic ◽  
Violeta Babic ◽  
Zoran Galic ◽  
Olivera Kosanin

The soils formed on sandstones in sessile oak forests (Quercetum montanum typicum Cer. et Jov. 1953) were researched in the area of Fruska Gora. On permanent sample plots established in management units ?Cortanovacka Forest-Hopovo-Velika Remeta? and ?Beocin-Manastir-Katanske Livade-Osovlje?, in the are of NP ?Fruska Gora?, aiming at the monitoring of the effect of light regime on the development of sessile oak progeny in the given environmental conditions, based on the morphogenetic characteristics of the soil and analytic values of the soil properties, and based on the soil classification by Skoric et al. (1985), the following two soil types were defined: acid brown soil (dystric cambisol), and illimerised soil (luvisol). Acid brown soil belongs to the form of medium deep soils, and illimerised soil is classified as deep soil.


2021 ◽  
Vol 42 ◽  
pp. e70549
Author(s):  
Jordi Bou ◽  
Lluís Vilar

The sessile oak forests found on the northeast of the Iberian Peninsula are ascribed to the Lathyro-Quercetumpetraeae association and play a key role in understanding the ecology of this habitat, as this region represents its xeric limit. For this reason, we analysed the biodiversity patterns and current conservation status of the sessile oak forests in the region. To do so, we collected Braun-Blanquet inventories of 34 plots randomly distributed throughout the sessile oak forests. The results showed a relationship between the climatic conditions and the biodiversity variables. While the richness of the community increased with decreasing temperatures, the characteristic species found within the community decreased at these same temperatures. This result was due to the presence of most companion species in the cool zones at high elevations.Sessile oaks are found close to other communities, such as silver birches and Scot pine forests.On the other hand, in the warm areas at low elevations, the sessile oak community was more established, with plants typical of this type of forest. These slightly warmer zones with sessile oaks are very important in terms of conservation and more vulnerable to climate change and the thermophilization of the community, as has been studied. As such, protecting and managing these forests is key to conserving this community. Nevertheless, as current protection measures do not safeguard most of these forests, it is essential to define a conservation strategy to preserve them. Using the conservation status, we have established criteria to improve the conservation strategy for sessile oak forest on the NE Iberian Peninsula.


2020 ◽  
Author(s):  
Maria Castellaneta ◽  
Angelo Rita ◽  
J. Julio Camarero ◽  
Michele Colangelo ◽  
Angelo Nolè ◽  
...  

<p>Several die-off episodes related to heat weaves and drought spells have evidenced the high vulnerability of Mediterranean oak forests. These events consisted in the loss in tree vitality and manifested as growths decline, elevated crown transparency (defoliation) and rising tree mortality rate. In this context, the changes in vegetation productivity and canopy greenness may represent valuable proxies to analyze how extreme climatic events trigger forest die-off. Such changes in vegetation status may be analyzed using remote-sensing data, specifically multi-temporal spectral information. For instance, the Normalized Difference Vegetation Index (NDVI) measures changes in vegetation greenness and is a proxy of changes in leaf area index (LAI), forest aboveground biomass and productivity. In this study, we analyzed the temporal patterns of vegetation in three Mediterranean oak forests showing recent die-off in response to the 2017 severe summer drought. For this purpose, we used an open-source platform (Google Earth Engine) to extract collections of MODIS NDVI time-series from 2000 to 2019. The analysis of both NDVI trends and anomalies were used to infer differential patterns of vegetation phenology among sites comparing plots where most trees were declining and showed high defoliation (test) versus plots were most trees were considered healthy (ctrl) and showed low or no defoliation. Here we discuss: i) the likely offset in NDVI time-series between test- versus ctrl- sites; and ii) the impact of summer droughts  on NDVI.</p><p><strong>Keywords</strong>: climate change, forest vulnerability, time series, remote sensing.</p>


2011 ◽  
Vol 28 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Zhaofei Fan ◽  
Xiuli Fan ◽  
Martin A. Spetich ◽  
Stephen R. Shifley ◽  
W. Keith Moser ◽  
...  

Abstract Black oak (Quercus velutina Lam.) and scarlet oak (Quercus coccinea Muenchh.)—two major components (44% of total stand basal area) of upland oak forests—are suffering severe decline and mortality in the Ozark Highlands, Missouri. However, factors influencing their survival (mortality) are not well understood. In this study we quantified how stand and tree-level predisposing factors are associated with survival of black and scarlet oaks. Sixteen-year monitoring data from the Missouri Ozark Forest Ecosystem Project (MOFEP) indicated that overall annual mortality of black and scarlet oaks averaged 2.2 and 1.7%, respectively, three to five times higher than expected (around 0.5%) for white oak, a common associate. For the first 8 years of the study (1990‐1998), survival rates of black and scarlet oaks were similar. Thereafter, the survival rate of black oak declined relative to scarlet oak. Using the classification and regression tree (CART) method we classified black oak and scarlet oak trees into seven and nine risk groups, respectively, that differed significantly in rates of tree mortality. Groups were distinguished based on tree diameter, crown class, and size relative to competitors. An oak decline and mortality hazard index was thus developed as the weighted means of risk group mortality, which can help managers prescribe species-specific silvicultural treatments to help mitigate oak decline and associated mortality.


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