scholarly journals Decomposition in mixed beech forests in the south-western Alps under severe summer drought

2020 ◽  
Author(s):  
Marion Jourdan ◽  
Stephan Hättenschwiler
Keyword(s):  
Tree Species ◽  
Abies Alba ◽  
Plant Litter ◽  
Summer Drought ◽  
Negative Effects ◽  
Beech Forests ◽  
N Loss ◽  
C And N ◽  
Litter Mixing ◽  
Drought Effects

ABSTRACTClimate and plant litter diversity are major determinants of carbon (C) and nitrogen (N) cycling rates during decomposition. Yet, how these processes will be modified with combined changes in climate and biodiversity is poorly understood. With a multisite field experiment, we studied the interactive effects of summer drought (using rainout shelters) and tree species mixing in beech forests in the French Alps. Forests included monospecific stands of Fagus sylvatica, Abies alba, and Quercus pubescens and two-species mixtures composed of beech and one of the other species. We hypothesized (1) negative effects of summer drought on C and N loss during decomposition and (2) mitigation of these negative effects in mixed tree species stands. Litter lost 35% of initial C, and 15% of N on average across all sites and litter types over 30 months of decomposition. Summer drought consistently, but weakly, reduced C loss but had no effect on N loss. Tree species mixing did not alter drought effects on decomposition but had non-additive effects on C and N loss, which were dominated by direct litter mixing rather than indirect tree canopy effects. Our data suggest relatively small drought effects on decomposition, possibly because process rates are generally slow during summer and because microsite variability exceeds that in response to rain exclusion. The dominant contribution of litter mixing to biodiversity effects supports the importance of microsite conditions for C and N dynamics during decomposition, which should be accounted for more explicitly in climate and biodiversity change predictions.

scholarly journals Metagenomic reconstruction of nitrogen and carbon cycling pathways in forest soil: Influence by different hardwood tree species

2020 ◽  
Author(s):  
Charlene N. Kelly ◽  
Geoffrey W. Schwaner ◽  
Jonathan R. Cumming ◽  
Timothy P. Driscoll
Keyword(s):  
Tree Species ◽  
Plant Litter ◽  
American Chestnut ◽  
Soil Microbiome ◽  
Red Oak ◽  
Black Cherry ◽  
Soil Microbial ◽  
Below Ground ◽  
C And N ◽  
Hardwood Tree

AbstractThe soil microbiome plays an essential role in processing and storage of nitrogen (N) and carbon (C), and is influenced by vegetation above-ground through imparted differences in chemistry, structure, mass of plant litter, root physiology, and dominant mycorrhizal associations. We used shotgun metagenomic sequencing and bioinformatic analysis to quantify the abundance and distribution of gene families involved in soil microbial N and C cycling beneath three deciduous hardwood tree species: ectomycorrhizal (ECM)-associated Quercus rubra (red oak), ECM-associated Castanea dentata (American chestnut), and arbuscular mycorrhizal (AM)-associated Prunus serotina (black cherry). Chestnut exhibited the most distinct soil microbiome of the three species, both functionally and taxonomically, with a general suppression of functional genes in the nitrification, denitrification, and nitrate reduction pathways. These changes were related to low inorganic N availability in chestnut stands as soil was modified by poor, low-N litter quality relative to red oak and black cherry soils.IMPORTANCEPrevious studies have used field biogeochemical process rates, isotopic tracing, and targeted gene abundance measurements to study the influence of tree species on ecosystem N and C dynamics. However, these approaches do not enable a comprehensive systems-level understanding of the relationship between microbial diversity and metabolism of N and C below-ground. We analyzed microbial metagenomes from soils beneath red oak, American chestnut, and black cherry stands and showed that tree species can mediate the abundance of key microbial genes involved in N and (to a lesser extent) C metabolism pathways in soil. Our results highlight the genetic framework underlying tree species’ control over soil microbial communities, and below-ground C and N metabolism, and may enable land managers to select tree species to maximize C and N storage in soils.

Admixing other tree species to European beech forests: Effects on soil organic carbon and total nitrogen stocks. A review.

2020 ◽  
Author(s):  
Stephanie Rehschuh ◽  
Michael Dannenmann
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Tree Species ◽  
Forest Floor ◽  
Mineral Soil ◽  
European Beech ◽  
Summer Drought ◽  
Beech Forests ◽  
Soc Stocks

<p>Drought-sensitive European beech forests are increasingly challenged by climate change. Admixing other, preferably more deep-rooting, tree species has been proposed to increase the resilience of beech forests to summer drought. This might not only alter soil water dynamics and availability, but also soil organic carbon (SOC) and total nitrogen (TN) storage in soils. Since information of these effects is scattered, our aim was to synthesize results from studies that compared SOC/TN stocks of beech monocultures with those of mixed beech stands as well as of other monocultures. We conducted a meta-analysis including 40 studies with 208, 231 and 166 observations for forest floor, mineral soil and the total soil profile, respectively. Pure conifer stands had higher SOC stocks compared to beech in general, especially in the forest floor with up to 200% (larch forests). Other broadleaved tree species (ash, oak, lime, maple, hornbeam) showed in comparison to beech lower SOC storage in the forest floor, with little impact on total stocks.  Similarly, for mixed beech-conifer stands we found significantly increased SOC stocks of >10% and a small increase in TN stocks of approx. 4% compared to beech monocultures, which means a potential SOC storage increase of >0.1 t ha<sup>-1</sup>yr<sup>-1 </sup>(transformation of mineral soil to 100 cm depth). In contrast, mixed beech-broadleaved stands did not show a significant change in total SOC stocks. Currently, the influence climatic and soil parameters on SOC changes due to admixture of other tree species is analyzed based on this dataset. This is expected to facilitate an assessment which mixtures with beech have the largest potential towards increasing SOC stocks.</p>

scholarly journals Long-term transformation of submontane spruce-beech forests in the Jizerské hory Mts.: dynamics of natural regeneration

2017 ◽  
Vol 63 (4) ◽  
pp. 213-225 ◽  
Author(s):  
Jiří Slanař ◽  
Zdeněk Vacek ◽  
Stanislav Vacek ◽  
Daniel Bulušek ◽  
Jan Cukor ◽  
...  
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Natural Regeneration ◽  
Abies Alba ◽  
Negative Influence ◽  
Silver Fir ◽  
Acer Pseudoplatanus ◽  
Beech Forests ◽  
Forest Transformation ◽  
Tree Layer

AbstractThe paper deals with development of the natural regeneration of even-aged spruce-beech forests during their transformation to uneven-aged stands with diversified structure at the Jedlový důl area in the Protected Landscape Area Jizerské hory Mts., Czech Republic. Shelterwood management system and free felling policy based on selection principles has been applied there since 1979 with the support of admixed tree species of the natural species composition, especially silver fir (Abies alba Mill.). The research was focuses on structure and development of natural regeneration with the emphasis on ungulate damage and interaction with tree layer from 1979 to 2015. In the course of 36 years, the regeneration structure was diversified towards the close-to-nature tree species composition, spatial and age structure. The number of regeneration recruits increased in average from 941 to 41,669 ind ha-1. During this period share of European beech (Fagus sylvatica L.) significantly (p < 0.01) increased (by 53.6%), while the share of Norway spruce (Picea abies [L.] Karst.) decreased (by 51.5%), such as damage caused by ungulate (by 61.4%) with the highest loses on sycamore maple (Acer pseudoplatanus L.), rowan (Sorbus aucuparia L.) and silver fir. Moreover, the parent trees had a significant negative influence on natural regeneration at smaller spacing (within a 1 - 5 m radius from the stem). Both, regeneration potential and effective role of the tree layer during the forest transformation has been confirmed as important prerequisites for ongoing forest transformation.

scholarly journals Comparison of C:N:P Stoichiometry in the Plant–Litter–Soil System Between Poplar and Elm Plantations in the Horqin Sandy Land, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Kai Wang ◽  
Risheng Zhang ◽  
Lining Song ◽  
Tao Yan ◽  
Enhang Na
Keyword(s):  
Tree Species ◽  
Plant Litter ◽  
Nutrient Cycle ◽  
Horqin Sandy Land ◽  
Sandy Land ◽  
Poplar Plantation ◽  
Soil System ◽  
Soil C ◽  
Soil C And N ◽  
C And N

Afforestation is among the most effective means of preventing and controlling desertification. Silver poplar (Populus alba) is commonly planted tree species for afforestation of the Horqin Sandy Land of China. However, this species has exhibited some drawbacks such as top shoot dieback, premature senescence and mortality, and soil and ecosystems degradation. In contrast, Siberian elm (Ulmus pumila) rarely experiences these problems in the same regions. Ecological stoichiometry plays a vital role in exploring ecological processes and nutrient cycle relationships in plant–litter–soil systems. To explore the differences in the carbon (C), nitrogen (N), and phosphorus (P) balance, the stoichiometry characteristics and stoichiometric homeostasis in elm and poplar plantations in the Horqin Sandy Land, we measured C, N, and P concentrations in leaves, branches, roots, litter, and soils and analyzed N and P resorption efficiencies in the two plantations. The results showed that soil C and N concentrations, C:P, and N:P were greater in the elm plantation than in the poplar plantation. The leaf and root C:P and N:P during summer and litter N and P concentrations were greater, whereas N and P resorption efficiencies were lower, in the elm plantation than in the poplar plantation. Generally, elm exhibited greater N:P homeostasis than poplar. N and N:P homeostasis were greater in roots than in leaves and branches in the elm plantation, but they varied with soil N concentration and N:P in the poplar plantation. These findings indicate that poplar exhibited more developed internal nutrient conservation and allocation strategies but poor nutrient accumulation in soil, which may contribute to degradation of poplar plantation. In contrast, elm tended to return more nutrients to the soil, showing an improved nutrient cycle in the plant–litter–soil system and increased soil C and N accumulation in the elm plantation. Therefore, compared with poplar, elm may be a more suitable afforestation tree species for the Horqin Sandy Land, in terms of promoting the accumulation of soil nutrients and enhancing nutrient cycling in the plant–litter–soil system.

scholarly journals Diverging Responses of Two Subtropical Tree Species (Schima superba and Cunninghamia lanceolata) to Heat Waves

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 513
Author(s):  
Luping Qu ◽  
Hans J. De Boeck ◽  
Huihua Fan ◽  
Gang Dong ◽  
Jiquan Chen ◽  
...  
Keyword(s):  
Water Transport ◽  
Tree Species ◽  
Heat Waves ◽  
Cunninghamia Lanceolata ◽  
Negative Effects ◽  
Xylem Embolism ◽  
Schima Superba ◽  
High Vapor ◽  
Use Efficiency ◽  
Coniferous Tree Species

The frequency and intensity of heat waves (HWs) has increased in subtropical regions in recent years. The mechanism underlying the HW response of subtropical trees remains unclear. In this study, we conducted an experiment with broad-leaved Schima superba (S. superba) and coniferous Cunninghamia lanceolata (C. lanceolata) seedlings to examine HW (5-day long) effects on stem water transport, leaf water use efficiency (WUE), morphology and growth, and to elucidate differences in the responses of both species. Our results indicated that HWs can significantly reduce hydraulic conductivity in both species. C. lanceolata experienced significant xylem embolism, with the percentage loss of conductivity (PLC) increasing by 40%, while S. superba showed a non-significant increase in PLC (+25%). Furthermore, HW also caused a reduction in photosynthesis rates (An), but transpiration rates (Tr) increased on the 5th day of the HW, together leading to a significant decrease in leaf WUE. From diurnal dynamics, we observed that the HW caused significant decrease of S. superba An only in the morning, but nearly the all day for C. lanceolata. During the morning, with a high vapor pressure deficit (VPD) environment, the HW increased Tr, which contributed a lot to latently cooling the foliage. In comparing the two tree species, we found that HW effects on S. superba were mostly short-term, with leaf senescence but limited or no xylem embolism. The surviving S. superba recovered rapidly, forming new branches and leaves, aided by their extensive root systems. For C. lanceolata, continued seedling growth initially but with subsequent xylem embolism and withering of shoots, led to stunted recovery and regrowth. In conclusion, apart from the direct thermal impacts caused by HW, drought stress was the main cause of significant negative effects on plant water transport and the photosynthetic system. Furthermore, S. superba and C. lanceolata showed clearly different responses to HW, which implies that the response mechanisms of broad-leaved and coniferous tree species to climate change can differ.

Factors influencing early vegetation establishment following soil scarification in a mixed forest in northern Japan

2005 ◽  
Vol 35 (1) ◽  
pp. 175-188 ◽  
Author(s):  
Toshiya Yoshida ◽  
Yoko Iga ◽  
Megumi Ozawa ◽  
Mahoko Noguchi ◽  
Hideaki Shibata
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Tree Species ◽  
Mixed Forest ◽  
Canopy Cover ◽  
Total Density ◽  
Dwarf Bamboo ◽  
Negative Effects ◽  
Tall Tree ◽  
Northern Japan

Scarification is widely conducted in northern Japan to remove understory dwarf bamboo species in degraded forests for replacement with tree species. To explore ways to enhance species diversity and restoration of mixed forest at the treated site, we clarified the mechanisms that lead to compositional heterogeneity of plant species. We evaluated the relative importance of environmental factors (scarification properties, soil properties, light conditions, litter cover, and presence of canopy trees) for the demography of tall tree species (emergence, mortality, and growth) and whole vegetation structure (species diversity and composition) over the two growing seasons immediately following scarification. Of tall tree species, Betula spp. were dominant (60% in total density), followed by Abies sachalinensis (Fr. Schm.) Masters, Acer mono Maxim., and Phellodendron amurense Rupr. Light intensity was an important factor, having mostly negative effects on the demography of these species. Soil factors (e.g., nitrogen content, moisture) affected the demography mainly of shade-intolerant or hygrophilous species. In general, extreme environmental conditions led to the dominance of grasses, forbs, and lianas rather than tall trees. Maintenance of canopy cover, which limits light and supplies seeds as well as litter, proved to be most important in promoting plant species diversification on the scarification site.

Antagonistic interactions between above- and belowground biota reduce their negative effects on a tree species

2020 ◽  
Vol 454 (1-2) ◽  
pp. 379-393
Author(s):  
Qiang Yang ◽  
Arjen Biere ◽  
Jeffrey A. Harvey ◽  
Jianqing Ding ◽  
Evan Siemann
Keyword(s):  
Tree Species ◽  
Negative Effects ◽  
Antagonistic Interactions

scholarly journals Molecular size distribution and hydrophilic and hydrophobic properties of humic acids isolated from forest soil

2008 ◽  
Vol 2 (No. 2) ◽  
pp. 45-53 ◽  
Author(s):  
B. Debska ◽  
M. Drag ◽  
M. Banach-Szott
Keyword(s):  
Humic Acids ◽  
Forest Soils ◽  
Tree Species ◽  
Plant Material ◽  
Molecular Size ◽  
European Beech ◽  
Plant Litter ◽  
Hydrophobic Properties ◽  
Degree Of Maturity ◽  
Molecular Size Distribution

The aim of the present paper was to determine hydrophilic and hydrophobic properties and the degree of polydispersity of humic acids depending on their degree of maturity and the properties of the plant material participating in the process of humification. The study involved humic acids isolated from samples taken from organic and mineral horizons of forest soils. The samples were taken under the tree stands of: pine with an admixture of hardbeam, European beech, elm, fir, spruce, and thuja. It was demonstrated that the properties of humic acids of the organic horizon and mineral horizons are determined by the kind of plant litter, mainly by the tree species. The humification process is connected with an increase of the proportion of humic acids of lower molecular size as compared to the proportion of molecules greater in size, and with an increase of hydrophilic fractions and a decrease of hydrophobic fractions. Based on the correlation relationships, it was shown that the degree of polydispersity of molecules of humic acids is related to their hydrophilic and hydrophobic properties. Humic acids with a larger proportion of high-molecular fractions demonstrate also a higher proportion of hydrophobic fractions.

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