scholarly journals Above-ground net primary productivity in young stands of beech and spruce

2013 ◽  
Vol 59 (3) ◽  
Author(s):  
Jozef Pajtík ◽  
Bohdan Konôpka ◽  
Róbert Marušák

AbstractOne of the expected consequences of climate change and its inherent phenomena to forest ecosystems is the gradual modification of their tree species composition (i.e. expansion of resistant species instead of less resistant ones). Climate change accompanied with increasing temperatures and a lack of precipitations may present a threat especially to spruce stands in the European part of the temperate zone. European beech is one of the possible forest tree species which might replace the potentially endangered spruce. In this paper, we observed, by using a combination of continual measurements and destructive whole-tree sampling, standing stocks of above-ground biomass (i.e. stem, branches, and foliage) and its annual net primary productivity (NPP) in naturally regenerated young stands of beech and spruce. We intentionally selected a site where the changing climate conditions are better suited to the ecological demands of beech rather than spruce (the species is dominant in the observed area). We recorded only small differences in the standing stock of stems of the beech, if based on tons per ha. However, this is in favor of spruce if based on cubic meters per ha. The largest difference between the species was found for the standing stock of foliage, spruce retained three times the biomass of beech. Also, beech allocated more carbohydrates to stem than spruce. On the other hand, we estimated nearly the same production of foliages and branches in both stands.

2020 ◽  
Vol 73 (1) ◽  
pp. 64-76
Author(s):  
Dagmar Zádrapová ◽  
Jiří Korecký ◽  
Jakub Dvořák ◽  
Zuzana Faltinová ◽  
Jan Bílý

Abstract European beech (Fagus sylvatica L.) is one of the most important broadleaved tree species in Europe both ecologically and economically. Nowadays, in the Czech Republic, beech is underrepresented in forest tree species composition, and there are tendencies to increase its proportion. When reintroducing beech, genetic variability, along with other factors, play a key role. The main aim of this study was to evaluate the genetic diversity of ten selected indigenous beech populations across the Czech Republic. Two hundred and fifty individuals were genotyped on 21 polymorphic nuclear microsatellite markers, which were amplified using two newly assembled multiplexes. According to the results, observed heterozygosity (Ho ) among populations ranged from 0.595 to 0.654 and expected heterozygosity (He ) from 0.650 to 0.678. That is comparable with the findings in other European studies. The high discriminatory power of the assembled multiplexes was confirmed by calculating the Probability of Identity among both unrelated and related individuals. Principal Coordinate Analysis (PCoA) based on Nei's genetic distances revealed that there are genetic differences among populations resulting in three approximate clusters (geographically north, south-east, and south-west). Nevertheless, the results implicate that on a geographical scale of the Czech Republic, the distance is unlikely to be the primary driver of genetic differentiation.


2013 ◽  
Vol 71 (2) ◽  
pp. 211-225 ◽  
Author(s):  
Christopher Reyer ◽  
Petra Lasch-Born ◽  
Felicitas Suckow ◽  
Martin Gutsch ◽  
Aline Murawski ◽  
...  

Ecosystems ◽  
2021 ◽  
Author(s):  
Laura Marqués ◽  
Drew M. P. Peltier ◽  
J. Julio Camarero ◽  
Miguel A. Zavala ◽  
Jaime Madrigal-González ◽  
...  

AbstractLegacies of past climate conditions and historical management govern forest productivity and tree growth. Understanding how these processes interact and the timescales over which they influence tree growth is critical to assess forest vulnerability to climate change. Yet, few studies address this issue, likely because integrated long-term records of both growth and forest management are uncommon. We applied the stochastic antecedent modelling (SAM) framework to annual tree-ring widths from mixed forests to recover the ecological memory of tree growth. We quantified the effects of antecedent temperature and precipitation up to 4 years preceding the year of ring formation and integrated management effects with records of harvesting intensity from historical forest management archives. The SAM approach uncovered important time periods most influential to growth, typically the warmer and drier months or seasons, but variation among species and sites emerged. Silver fir responded primarily to past climate conditions (25–50 months prior to the year of ring formation), while European beech and Scots pine responded mostly to climate conditions during the year of ring formation and the previous year, although these responses varied among sites. Past management and climate interacted in such a way that harvesting promoted growth in young silver fir under wet and warm conditions and in old European beech under drier and cooler conditions. Our study shows that the ecological memory associated with climate legacies and historical forest management is species-specific and context-dependent, suggesting that both aspects are needed to properly evaluate forest functioning under climate change.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhe Yuan ◽  
Yongqiang Wang ◽  
Jijun Xu ◽  
Zhiguang Wu

AbstractThe ecosystem of the Source Region of Yangtze River (SRYR) is highly susceptible to climate change. In this study, the spatial–temporal variation of NPP from 2000 to 2014 was analyzed, using outputs of Carnegie–Ames–Stanford Approach model. Then the correlation characteristics of NPP and climatic factors were evaluated. The results indicate that: (1) The average NPP in the SRYR is 100.0 gC/m2 from 2000 to 2014, and it shows an increasing trend from northwest to southeast. The responses of NPP to altitude varied among the regions with the altitude below 3500 m, between 3500 to 4500 m and above 4500 m, which could be attributed to the altitude associated variations of climatic factors and vegetation types; (2) The total NPP of SRYR increased by 0.18 TgC per year in the context of the warmer and wetter climate during 2000–2014. The NPP was significantly and positively correlated with annual temperature and precipitation at interannual time scales. Temperature in February, March, May and September make greater contribution to NPP than that in other months. And precipitation in July played a more crucial role in influencing NPP than that in other months; (3) Climatic factors caused the NPP to increase in most of the SRYR. Impacts of human activities were concentrated mainly in downstream region and is the primary reason for declines in NPP.


2014 ◽  
Vol 7 (1) ◽  
pp. 1535-1600
Author(s):  
M. Scherstjanoi ◽  
J. O. Kaplan ◽  
H. Lischke

Abstract. To be able to simulate climate change effects on forest dynamics over the whole of Switzerland, we adapted the second generation DGVM LPJ-GUESS to the Alpine environment. We modified model functions, tuned model parameters, and implemented new tree species to represent the potential natural vegetation of Alpine landscapes. Furthermore, we increased the computational efficiency of the model to enable area-covering simulations in a fine resolution (1 km) sufficient for the complex topography of the Alps, which resulted in more than 32 000 simulation grid cells. To this aim, we applied the recently developed method GAPPARD (Scherstjanoi et al., 2013) to LPJ-GUESS. GAPPARD derives mean output values from a combination of simulation runs without disturbances and a patch age distribution defined by the disturbance frequency. With this computationally efficient method, that increased the model's speed by approximately the factor 8, we were able to faster detect shortcomings of LPJ-GUESS functions and parameters. We used the adapted LPJ-GUESS together with GAPPARD to assess the influence of one climate change scenario on dynamics of tree species composition and biomass throughout the 21st century in Switzerland. To allow for comparison with the original model, we additionally simulated forest dynamics along a north-south-transect through Switzerland. The results from this transect confirmed the high value of the GAPPARD method despite some limitations towards extreme climatic events. It allowed for the first time to obtain area-wide, detailed high resolution LPJ-GUESS simulation results for a large part of the Alpine region.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Xavier Morin ◽  
Lorenz Fahse ◽  
Hervé Jactel ◽  
Michael Scherer-Lorenzen ◽  
Raúl García-Valdés ◽  
...  

2018 ◽  
Vol 15 (4) ◽  
pp. 1173-1183 ◽  
Author(s):  
Aaron M. Sparks ◽  
Crystal A. Kolden ◽  
Alistair M. S. Smith ◽  
Luigi Boschetti ◽  
Daniel M. Johnson ◽  
...  

Abstract. Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy – FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from −67 to −312 g C m−2 yr−1 (−13 to −54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose–response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.


2021 ◽  
Author(s):  
Katharina Enigl ◽  
Matthias Schlögl ◽  
Christoph Matulla

<p>Climate change constitutes a main driver of altering population dynamics of spruce bark beetles (<em>Ips typographus</em>) all over Europe. Their swarming activity as well as development rate are strongly dependent on temperature and the availability of brood trees. Especially over the last years, the latter has substantially increased due to major drought events which led to a widespread weakening of spruce stands. Since both higher temperatures and longer drought periods are to be expected in Central Europe in the decades ahead, foresters face the challenges of maintaining sustainable forest management and safeguarding future yields. One approach used to foster decision support in silviculture relies on the identification of possible alternative tree species suitable for adapting to expected future climate conditions in threatened regions. </p><p>In this study, we focus on the forest district of Horn, a region in Austria‘s north east that is beneficially influenced by the mesoclimate of the Pannonian basin. This fertile yet dry area has been severely affected by mass propagations of <em>Ips typographus</em> due to extensive droughts since 2017, and consequently has suffered from substantial forest damage in recent years. The urgent need for action was realized and has expedited the search for more robust alternative species to ensure sustainable silviculture in the area.</p><p>The determination of suitable tree species is based on the identification of regions whose climatic conditions in the recent past are similar to those that are to be expected in the forest district of Horn in the future. To characterize these conditions, we consider 19 bioclimatic variables that are derived from monthly temperature and rainfall values. Using downscaled CMIP6 projections with a spatial resolution of 2.5 minutes, we determine future conditions in Horn throughout the 21st century. By employing 20-year periods from 2021 to 2100 for the scenarios SSP1-26, SSP2-45, SSP3-70 and SSP5-85,  and comparing them to worldwide past climate conditions, we obtain corresponding bioclimatic regions for four future time slices until the end of the century. The Euclidian distance is applied as measure of similarity, effectively yielding similarity maps on a continuous scale. In order to account for the spatial variability within the forest district, this procedure is performed for the colder northwest and the warmer southeast of the area, individually seeking similar bioclimatic regions for each of these two subregions. Results point to Eastern Europe as well as the Po Valley in northern Italy as areas exhibiting the highest similarity to the future climate in this North-Eastern part of Austria.</p>


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