scholarly journals Leaching of inorganic and organic phosphorus and nitrogen in contrasting beech forest soils – seasonal patterns and effects of fertilization

2021 ◽  
Author(s):  
Jasmin Fetzer ◽  
Emmanuel Frossard ◽  
Klaus Kaiser ◽  
Frank Hagedorn
Keyword(s):  
Organic Phosphorus ◽  
High Sensitivity ◽  
European Beech ◽  
P System ◽  
P Fertilization ◽  
N Losses ◽  
Major Pathway ◽  
Climate Conditions ◽  
Organic Layers ◽  
P Fluxes

Abstract. Leaching is one major pathway of phosphorus (P) and nitrogen (N) losses from forest ecosystems. Using a full factorial N×P fertilization and irrigation experiment, we investigated the leaching of dissolved organic and inorganic P (DOP and DIP) and N (DON and DIN) from organic layers (litter, Oe/Oa horizons) and mineral A horizons at two European beech sites of contrasting P status. Leachates showed highest DIP and DIN concentrations in summer and lowest in winter, while dissolved organic forms remained rather constant throughout seasons. During the dry and hot summer 2018, DOC : DOP and DOC : DON ratios in leachates were particularly narrow, suggesting a release of microbial P due to cell lysis by drying and rewetting. This effect was stronger at the low-P site. The estimated annual mean fluxes from the Oe/Oa horizons in the non-fertilized treatment were 60 and 30 mg m−2 yr−1 for total dissolved P and 730 and 650 mg m−2 yr−1 for total dissolved N at the high-P and the low-P site, respectively. Fluxes of P were highest in the organic layers and decreased towards the A horizon, likely due to sorption by minerals. Fertilization effects were additive at the high-P, but antagonistic at the low-P site: At the high-P site, fertilization with +N, +P, and +N+P increased total P fluxes from the Oe/Oa horizon by +33, +51, and +75 %, while the respective increases were +198, +156, and +10 % at the low-P site. The positive N-effect on DIP leaching possibly results from a removed N limitation of phosphatase activity at the low-P site. Fluxes of DOP remained unaffected by fertilization. Fluxes of DIN and DON from the Oe/Oa horizons increased upon +N and +N+P, but not upon +P fertilization. In conclusion, the estimated P fluxes from the A horizons were comparable in magnitude to reported atmospheric P inputs, suggesting that these systems do not deplete in P due to leaching. However, a particularly high sensitivity of DIP leaching to hotter and drier conditions suggests accelerated P losses under the expected more extreme future climate conditions. Increases of P leaching due to fertilization and drying-rewetting were higher in the low-P system, implying that the low-P system is more susceptible to environmental future changes.

scholarly journals Distribution of the timber quality attribute ‘knot surface’ in logs of Fagus sylvatica L. from pure and mixed forest stands

2021 ◽  
Author(s):  
Kirsten Höwler ◽  
Torsten Vor ◽  
Peter Schall ◽  
Peter Annighöfer ◽  
Dominik Seidel ◽  
...  
Keyword(s):  
Fagus Sylvatica ◽  
Mixed Forest ◽  
European Beech ◽  
Forest Stands ◽  
Species Identity ◽  
Mixed Stands ◽  
Mixed Forests ◽  
Climate Conditions ◽  
Timber Quality ◽  
Positive Effects

AbstractResearch on mixed forests has mostly focused on tree growth and productivity, or resistance and resilience in changing climate conditions, but only rarely on the effects of tree species mixing on timber quality. In particular, it is still unclear whether the numerous positive effects of mixed forests on productivity and stability come at the expense of timber quality. In this study, we used photographs of sawn boards from 90 European beech (Fagus sylvatica L.) trees of mixed and pure forest stands to analyze internal timber quality through the quality indicator knot surface that was quantitatively assessed using the software Datinf® Measure. We observed a decrease in knot surface with increasing distance from the pith as well as smaller values in the lower log sections. Regarding the influence of neighborhood species identity, we found only minor effects meaning that timber qualities in mixed stands of beech and Norway spruce (Picea abies (L.) H. Karst.) tended to be slightly worse compared to pure beech stands.

scholarly journals Disentangling the Legacies of Climate and Management on Tree Growth

Ecosystems ◽  
2021 ◽  
Author(s):  
Laura Marqués ◽  
Drew M. P. Peltier ◽  
J. Julio Camarero ◽  
Miguel A. Zavala ◽  
Jaime Madrigal-González ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Management ◽  
Tree Growth ◽  
European Beech ◽  
Ring Formation ◽  
Silver Fir ◽  
Past Climate ◽  
Climate Conditions ◽  
Ecological Memory ◽  
Historical Forest

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.

scholarly journals Drivers of nitrogen leaching from organic layers in Central European beech forests

2016 ◽  
Vol 403 (1-2) ◽  
pp. 343-360 ◽  
Author(s):  
Martin T. Schwarz ◽  
Sebastian Bischoff ◽  
Stefan Blaser ◽  
Steffen Boch ◽  
Fabrice Grassein ◽  
...  
Keyword(s):  
European Beech ◽  
Nitrogen Leaching ◽  
Beech Forests ◽  
Central European ◽  
Organic Layers

An improved method for determining microbially available phosphorus in drinking water

2016 ◽  
Vol 16 (4) ◽  
pp. 1149-1158 ◽  
Author(s):  
Gang Wen ◽  
Qin Deng ◽  
Ting-Lin Huang ◽  
Jun Ma
Keyword(s):  
Drinking Water ◽  
Microbial Consortium ◽  
Incubation Temperature ◽  
Organic Phosphorus ◽  
High Sensitivity ◽  
Cell Number ◽  
Growth Potential ◽  
Utilization Efficiency ◽  
Available Phosphorus ◽  
Time Saving

Microbially available phosphorus (MAP) is the labile phosphorus that is readily assimilated by microorganisms, which is linearly correlated to bacterial re-growth in drinking water in some regions. The conventional MAP bioassay for drinking water was originally developed by Markku based on the growth potential of Pseudomonas fluorescens P17 (P17). However, the bioassay bears some demerits, such as time-consuming and labor-intensive enumeration. For convenience, an alternative method based on a similar principle was developed to assess the content of MAP in drinking water, in which natural microbial consortium was used as inoculum instead of pure culture P17, cell number was counted using flow cytometry (FCM), and cultivation at 30 °C was adopted. Natural microbial consortium is able to efficiently utilize organic phosphorus and exhibit high sensitivity since more cells are produced per μg P utilized. FCM is a rapid method to count all bacteria growing in drinking water. With incubation temperature increasing up to 30 °C, there is a shorter test period (64 h), excellent sensitivity and better utilization efficiency for organic phosphorus. The results show that the developed bioassay is sensitive, time-saving and easily operated.

scholarly journals Biogeochemical controls of surface ocean phosphate

2019 ◽  
Vol 5 (8) ◽  
pp. eaax0341 ◽  
Author(s):  
Adam C. Martiny ◽  
Michael W. Lomas ◽  
Weiwei Fu ◽  
Philip W. Boyd ◽  
Yuh-ling L. Chen ◽  
...  
Keyword(s):  
Regional Differences ◽  
High Sensitivity ◽  
Nutrient Supply ◽  
Earth System ◽  
Lateral Transport ◽  
Climate Conditions ◽  
Surface Ocean ◽  
Earth System Models ◽  
Incomplete Picture

Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the vertical nutrient supply and surface lateral transport are additional drivers of phosphate concentrations. Our study demonstrates the importance of accurately quantifying nutrients for understanding the regulation of ocean ecosystems and biogeochemistry now and under future climate conditions.

scholarly journals Locomotion of Slope Geohazards Responding to Climate Change in the Qinghai-Tibetan Plateau and Its Adjacent Regions

2021 ◽  
Vol 13 (19) ◽  
pp. 10488
Author(s):  
Yiru Jia ◽  
Jifu Liu ◽  
Lanlan Guo ◽  
Zhifei Deng ◽  
Jiaoyang Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Climatic Factors ◽  
High Sensitivity ◽  
Spatial Location ◽  
Future Climate ◽  
Tibet Plateau ◽  
The South ◽  
Climate Conditions ◽  
Temperature And Precipitation ◽  
Qinghai Tibet Plateau

Slope geohazards, which cause significant social, economic and environmental losses, have been increasing worldwide over the last few decades. Climate change-induced higher temperatures and shifted precipitation patterns enhance the slope geohazard risks. This study traced the spatial transference of slope geohazards in the Qinghai-Tibet Plateau (QTP) and investigated the potential climatic factors. The results show that 93% of slope geohazards occurred in seasonally frozen regions, 2.6% of which were located in permafrost regions, with an average altitude of 3818 m. The slope geohazards are mainly concentrated at 1493–1988 m. Over time, the altitude of the slope geohazards was gradually increased, and the mean altitude tended to spread from 1984 m to 2562 m by 2009, while the slope gradient varied only slightly. The number of slope geohazards increased with time and was most obvious in spring, especially in the areas above an altitude of 3000 m. The increase in temperature and precipitation in spring may be an important reason for this phenomenon, because the results suggest that the rate of air warming and precipitation at geohazard sites increased gradually. Based on the observation of the spatial location, altitude and temperature growth rate of slope geohazards, it is noted that new geohazard clusters (NGCs) appear in the study area, and there is still a possibility of migration under the future climate conditions. Based on future climate forecast data, we estimate that the low-, moderate- and high-sensitivity areas of the QTP will be mainly south of 30° N in 2030, will extend to the south of 33° N in 2060 and will continue to expand to the south of 35° N in 2099; we also estimate that the proportion of high-sensitivity areas will increase from 10.93% in 2030 to 14.17% in 2060 and 17.48% in 2099.

scholarly journals Growth response of mixed beech forests to climate change, various management and game pressure in Central Europe

2019 ◽  
Vol 65 (No. 9) ◽  
pp. 331-345 ◽  
Author(s):  
Stanislav Vacek ◽  
Anna Prokůpková ◽  
Zdeněk Vacek ◽  
Daniel Bulušek ◽  
Václav Šimůnek ◽  
...  
Keyword(s):  
Stand Structure ◽  
Abies Alba ◽  
European Beech ◽  
Silver Fir ◽  
Timber Production ◽  
Beech Forests ◽  
Great Density ◽  
Climate Conditions ◽  
Growth Variability ◽  
Browsing Damage

The growth, structure and production of mixed beech (Fagus sylvatica L.) forests were analysed  in the Broumovsko Protected Landscape Area, Czech Republic. The objective of the paper was to evaluate stand structure, timber production and dynamics of forests with historically different silvicultural practices in relation to climate conditions, management and game damage. The results indicate that scree forests (coppices and coppices with standards) were stands with high-rich species diversity and structure compared to herb-rich beech forests (high forests) with higher timber production. The Norway spruce (Picea abies [L.] Karst.) was the most sensitive tree species compared to low growth variability in European beech. The climate factors had the highest effect on radial growth from June to August. Natural regeneration showed great density potential (13,880–186,462 recruits·ha<sup>–1</sup>), especially in expansion of maples and European ash (Fraxinus excelsior L.). However, recruits were seriously limiting by damage caused by hoofed game, especially in silver fir (Abies alba Mill.; 53% browsing damage), wych elm (Ulmus glabra Hudson; 51%) and rowan (Sorbus aucuparia L.; 50%).

scholarly journals Modifying elastic modulus of two-component polyurethane adhesive for structural hardwood bonding

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
S. Bockel ◽  
S. Harling ◽  
J. Konnerth ◽  
P. Niemz ◽  
G. Weiland ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Polymer Films ◽  
Modulus Of Elasticity ◽  
Beech Wood ◽  
European Beech ◽  
Lap Joints ◽  
Climate Conditions ◽  
Wetting Properties ◽  
Two Component ◽  
Dry Conditions

Abstract Subject to this study is the modification of an experimental two-component polyurethane (2C PUR) as an alternative adhesive for structural hardwood bonding. The 2C PUR has been adapted by calcium carbonate as filler to increase its modulus of elasticity with the aim of increasing the modulus analogue to the ones typically observed for classic amino- and phenol based adhesives. The 2C PUR system was compared with a commercial one-component polyurethane (1C PUR) and a phenol resorcinol formaldehyde (PRF) adhesive. The wetting properties of the adhesives were tested in terms of surface tension, polar and dispersive part and contact angle on European beech wood (Fagus sylvatica L.). In addition, adhesive polymer films of 2C PUR were tested for tensile strength and modulus of elasticity (E-Modulus) following ISO 527-1. The adhesives bond performance on beech wood was determined by lap-joints according to EN 302-1 in various climate conditions. The results show that 2C PUR has proper wettability properties on beech wood. Adding 60% wt filler to the polyol component increased the E-Modulus from 2.3 GPa (0%) to 4.4 GPa. The tensile strength of the modified 2C PUR polymer films was comparable with the industrial 1C PUR. Tensile shear strength and wood failure percentage of 2C PUR lap-joints were increased by adding filler and met requirements in dry and re-dried conditions according to EN 302-1. However, the addition of filler didn’t result in an improvement in wet conditions. The present study shows sufficient performance for bonding hardwood with 2C PUR in dry conditions, while the system still needs to be improvement regarding its performance in humid conditions.

scholarly journals Linking Soil Acidity to P Fractions and Exchangeable Base Cations under Increased N and P Fertilization of Mono and Mixed Plantations in Northeast China

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1274
Author(s):  
Nowsherwan Zarif ◽  
Attaullah Khan ◽  
Qingcheng Wang
Keyword(s):  
Soil Acidification ◽  
Northeast China ◽  
Soil Acidity ◽  
Organic Phosphorus ◽  
Base Cations ◽  
N Deposition ◽  
Limiting Factor ◽  
P Availability ◽  
P Fertilization ◽  
P Addition

Atmospheric N deposition is increasing worldwide, especially in China, significantly affecting soil health, i.e., increasing soil acidification. The northern region of China is considered to be one of the N deposition points in Asia, ranging from 28.5 to 100.4 N ha−1yr−1. Phosphorus (P) is the limiting factor in the temperate ecosystem and an important factor that makes the ecosystem more susceptible to N-derived acidification. However, it remained poorly understood how the soil acidification process affects soil P availability and base cations in the temperate region to increased N deposition. To address this question, in May 2019, a factorial experiment was conducted under N and P additions with different plantations in Maoershan Experimental Forest Farm, Northeast China, considering species and fertilization as variables. The effective acidity (EA) increased by N and NP fertilizations but was not significantly affected by P fertilization. Similarly, the pH, base saturation percentage (BS%), calcium (Ca2+), and magnesium (Mg2+) were decreased under N addition, while the Al:Ca ratio increased, whereas NaHCO3 inorganic phosphorus (Pi) and NaOH organic phosphorus (Po) significantly decreased under N enrichments. However, NaOH Pi increased in N-enriched plots, while H2O Pi and NaHCO3 Pi increased under the P addition. Thus, the results suggest that the availability of N triggers the P dynamics by increasing the P uptake by trees. The decrease in base cations, Ca2+, and Mg2+ and increase in exchangeable Fe3+ and Al3+ ions are mainly responsible for soil acidification and lead to the depletion of soil nutrients, which, ultimately, affects the vitality and health of forests, while the P addition showed a buffering effect but could not help to mitigate the soil acidity.

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