scholarly journals Forest defoliator pests alter carbon and nitrogen cycles

2016 ◽  
Vol 3 (10) ◽  
pp. 160361 ◽  
Author(s):  
Anne l-M-Arnold ◽  
Maren Grüning ◽  
Judy Simon ◽  
Annett-Barbara Reinhardt ◽  
Norbert Lamersdorf ◽  
...  

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea  L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata  L.) and mottled umber ( Erannis defoliaria  L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

2019 ◽  
Author(s):  
Jörg Matschullat ◽  
Roberval Monteiro Bezerra de Lima ◽  
Sophie F. von Fromm ◽  
Solveig Pospiech ◽  
Andrea M. Ramos ◽  
...  

Abstract. Given the dimensions of the Amazon basin (7.5 million km2), its internal dynamics, increasing anthropogenic strain on this large biome, and its global role as one of two continental biospheric tipping elements, it appears crucial to have data-based knowledge on carbon and nitrogen concentrations and pools as well as on possible intra-annual dynamics. We quantified carbon (Ct, Corg), nitrogen (N) and sulfur (S) concentrations in litter (ORG) and mineral soil material (TOP 0–20 cm, BOT 30–50 cm) of upland (terra firme) oxisols across Amazonas state and present a first pool calculation. Data are based on triplicate seasonal sampling at 29 sites (forest and post-forest) within the binational project EcoRespira-Amazon (ERA). Repeated sampling increased data accuracy and allows for interpreting intra-annual (seasonal) and climate-change related dynamics. Extreme conditions between the dry season in 2016 and the subsequent wet season (ENSO-related) show differences more clearly. Median CNS in the Amazon basin TOP soils (Ct 1.9, Corg 1.6, N 0.15, S 0.03 wt-% under forest canopy) as well as Corg / N ratios show concentrations similar to European soils (FOREGS, GEMAS). TOP Ct concentrations ranged from 1.02 to 3.29 wt-% (medianForest 2.17 wt-%; medianPost-Forest 1.75 wt-%), N from 0.088 to 0.233 wt-% (medianForest 0.17 wt-%; medianPost-Forest 0.09 wt-%) and S from 0.012 to 0.051 wt.-% (medianForest 0.03 wt.-%; medianPost-Forest 0.02 wt-%). Corg / N ratios ranged from 6 to 14 (median 10). A first pool calculation (hectare-based) illustrates forest versus post-forest changes. The elements are unevenly distributed in the basin with generally higher CNS values in the central part (Amazonas graben) as compared to the southern part of the basin. Deforestation and drought conditions lead to C and N losses – within 50 years after deforestation, C and N losses average 10 to 15 %. Regional climate change with increased drought will likely speed up carbon and nitrogen losses.


2021 ◽  
Author(s):  
Yanghua Yu ◽  
Yingu Wu ◽  
Yanping Song ◽  
Yitong Li

Abstract Background and aimsUnderstanding the relationship between carbon, nitrogen and their stable isotope 13C, 15N and soil stoichiometry may assist to reveal the distribution pattern and stability mechanism of nutrient elements in karst ecosystem.MethodsFour plantations of Zanthoxylum planispinum var. dintanensis (5–7, 10–12, 20–22 and 30–32 years) in the karst plateau gorge area of Guizhou Province, China, were selected as the research objects to clarify the variation characteristics and interaction effects of leaf, litter, soil C, N and their isotopes with plantation age, and to explore the relationship between soil stoichiometry and the 13C, 15N of Zanthoxylum planispinum var. dintanensis plantation.Results(1) the 13C in leaf, litter and soil were − 28.04‰±0.59‰, -26.85‰±0.67‰ and − 19.39‰±1.37‰, respectively, correspondingly, the contents of 15N were 2.01‰±0.99‰, 2.91‰±1.32‰ and 3.29‰±0.69‰, respectively. The contents of the 13C and 15N can be rank ordered as soil > litter > leaf; (2) with the increase of plantation age, the soil 13C decreased; the leaf and litter 15N increased first then decreased; the litter 13C and soil 15N did not vary significantly; (3) the litter layer positively correlated to soil 13C, and negatively correlated to 15N; (4) redundancy analysis showed that soil microbial biomass carbon (MBC) and bacteria/fungi (BAC/FUN) were the dominant factors affecting C and N isotope natural abundances.ConclusionsThis study indicated that the species and acidity of soil microbial can affect the C and N isotope natural abundance.


2009 ◽  
Vol 66 (1) ◽  
pp. 132-135 ◽  
Author(s):  
Elizabeth J. Avramides ◽  
Matina Christou ◽  
David L. Jones

Many temperate agricultural soils have prolonged periods in the winter when plant carbon inputs to the soil are low. Soil maintained at low temperature in the absence of plants was used to simulate the conditions in a vineyard soil during winter. In a four month simulated overwintering period we showed that the concentration of dissolved organic carbon and nitrogen in soil solution slowly declined alongside heterotrophic soil respiration. Measurements of free amino acid concentrations and turnover indicated that the amino acid pool in soil was rapidly depleted but readily replenished throughout the four-month period. This indicates that the soil contained intrinsic reserves of labile C that was capable of supporting the soil microbial community in times of reduced plant C inputs.


2017 ◽  
Vol 25 (6) ◽  
pp. 5550-5557 ◽  
Author(s):  
Pascale Bourgeade ◽  
Mohamed Bourioug ◽  
Sandra Macor ◽  
Laurence Alaoui-Sossé ◽  
Badr Alaoui-Sossé ◽  
...  

Author(s):  
И.А. Уткина ◽  
В.В. Рубцов

Дубовая широкоминирующая моль Acrocercops brongniardella (Fabricius, 1798) (Lepidoptera, Gracillariidae) давно известный и массово размножающийся в дубравах европейской части России, Украины, странах Западной Европы вид филлофаговминёров. В последние два десятилетия появились свидетельства увеличения её численности в ряде регионов. Вместе с тем до сих пор остаются пробелы в знаниях об особенностях развития этого вида. По мнению одних ученых, моль производит одно поколение в год, других два. Такое расхождение может быть связано с разной погодной ситуацией в разных местообитаниях или изменяющимися условиями одного и того же местообитания. При одновременном массовом размножении дубовой широкоминирующей моли и зимней пяденицы Operophtera brumata (Linnaeus, 1758) (Lepidoptera: Geometridae) дефолиация крон обеих феноформ дуба происходит поразному, что связано с тем, что первичную листву ранней формы дуба, повреждённую зимней пяденицей, моль не заселяет и начинает минировать листья дуба поздней и промежуточных форм, не повреждённых зимней пяденицей, что увеличивает уровень их дефолиации. После окукливания зимней пяденицы, при появлении на раннем дубе нежной вторичной листвы, дубовая широкоминирующая моль успешно её осваивает. Деревья дуба при этом испытывают более продолжительное и интенсивное повреждение листвы разных генераций, что сказывается на их текущем состоянии и дальнейшем развитии. Таким образом, при высокой плотности популяции зимней пяденицы она оказывает определенное давление на популяцию дубовой широкоминирующей моли, лишая её возможности питаться весенней листвой дуба ранней формы. Лёт бабочек дубовой широкоминирующей моли ежегодно продолжительный в течение всего летнего периода он проходит очень неравномерно в разных типах дубрав и существенно зависит от погодных условий. Ее высокая вредоносность сохраняется. Вспышка зимней пяденицы прекратилась после сильных морозов в январе феврале 2012 г. The brown oak slender Acrocercops brongniardella (F., 1798) (Lepidoptera, Gracillariidae) is a wellknown species of leaf miners that has been widely reproducing in oak forests of the European part of Russia, Ukraine, and Western European countries. In the past two decades, evidence of an increase in its abundance and population density in some regions has appeared. However, there are still gaps in knowledge on the development features of this species. According to some authors, the moth produces one generation per year, while other authors indicate two. This discrepancy may be due to different weather conditions in different habitats, or the change in conditions of the same habitat. With simultaneous mass reproduction of the brown oak slender and the winter moth Operophtera brumata (L., 1758) (Lepidoptera: Geometridae), the defoliation of the crowns of both phenological forms of the oak occurs differently, due to the fact that the primary foliage of the early form of the oak damaged by the winter moth, the brown oak slender does not colonize and begins to mine the leaves of the oak of the late and intermediate forms not damaged by the winter moth. This increases the level of defoliation. After pupation of the winter moth, when delicate secondary foliage appears on early oak, the brown oak slender successfully utilizes it. At this point, oak trees experience a more prolonged and intensive damage to the foliage of different generations, which affects their current state and further development. Thus, at a high density of the winter moth population, it exerts a certain pressure on the population of the brown oak slender, depriving it of the opportunity to feed on the spring foliage of the earlyshaped oak. The flight of the brown oak slender is annually long, during the whole summer, but it occurs very unevenly in different types of oak forests and significantly depends on the weather conditions. The damage caused by the brown oak slender is still high. The outbreak of the winter moth stopped after a severe frost in January February of 2012.


2020 ◽  
Vol 33 (1) ◽  
pp. 31-42 ◽  
Author(s):  
SARAH PRISCILLA DO NASCIMENTO AMORIM ◽  
CÁCIO LUIZ BOECHAT ◽  
LIZANDRA DE SOUSA LUZ DUARTE ◽  
CÍNTIA BEZERRA ROCHA ◽  
FILIPE SELAU CARLOS

ABSTRACT The cover crop straw may cause changes in the microbial activity and population, with repercussions on environmental changes and on the C and N dynamics, providing important information for the planning of adequate land use in the Cerrado. The objective of this study was to evaluate the effect of straw of cover crops on the soil microbial attributes and quality of organic matter. Experimental units consisted of 100 g of sieved soil placed in small plastic cups mixed with straw from cover plants. Treatments were distributed in a CRD, in a factorial scheme of 7 x 7 + 1, with seven types of straw, evaluated at 7, 14, 21, 28, 42, 63 and 105 days after incubation, and control without straw, with three replicates. The qCO2 ranged from 0.1 (Crotalaria spectabilis at 14 days) to 5.1% (Cajanus cajan ‘IAPAR 43’ at 42 days). The organic carbon and nitrogen reservoir are differently affected by straw of legumes and grasses on the dates. The incorporation of Brachiaria brizantha and Mucuna aterrima had a positive impact on the microbial attributes until the 21st incubation (qCO2, Cmic and Nmic), with little loss of carbon dioxide and growth of the microbial population. All the evaluated species presented a potential to be used in crop rotation systems, enabling no-tillage systems in the Cerrado of Piauí. However, it is recommended to select species according to specific purposes. Thus, the use of cover crops is an important tool for increasing the biological quality of Brazilian northeastern cerrado soils.


2021 ◽  
Vol 318 ◽  
pp. 107490
Author(s):  
Marie Sünnemann ◽  
Julia Siebert ◽  
Thomas Reitz ◽  
Martin Schädler ◽  
Rui Yin ◽  
...  

2018 ◽  
Author(s):  
Spencer Diamond ◽  
Peter Andeer ◽  
Zhou Li ◽  
Alex Crits-Christoph ◽  
David Burstein ◽  
...  

AbstractSoil microbial activity drives the carbon and nitrogen cycles and is an important determinant of atmospheric trace gas turnover, yet most soils are dominated by organisms with unknown metabolic capacities. Even Acidobacteria, among the most abundant bacteria in soil, remain poorly characterized, and functions across groups such as Verrucomicrobia, Gemmatimonadetes, Chloroflexi, Rokubacteria are understudied. Here, we resolved sixty metagenomic, and twenty proteomic datasets from a grassland soil ecosystem and recovered 793 near-complete microbial genomes from 18 phyla, representing around one third of all organisms detected. Importantly, this enabled extensive genomics-based metabolic predictions for these understudied communities. Acidobacteria from multiple previously unstudied classes have genomes that encode large enzyme complements for complex carbohydrate degradation. Alternatively, most organisms we detected encode carbohydrate esterases that strip readily accessible methyl and acetyl groups from polymers like pectin and xylan, forming methanol and acetate, the availability of which could explain high prevalences of C1 metabolism and acetate utilization in genomes. Organism abundances among samples collected at three soil depths and under natural and amended rainfall regimes indicate statistically higher associations of inorganic nitrogen metabolism and carbon degradation in deep and shallow soils, respectively. This partitioning decreased in samples under extended spring rainfall indicating long term climate alteration can affect both carbon and nitrogen cycling. Overall, by leveraging natural and experimental gradients with genome-resolved metabolic profiles, we link organisms lacking prior genomic characterization to specific roles in complex carbon, C1, nitrate, and ammonia transformations and constrain factors that impact their distributions in soil.


2017 ◽  
Vol 6 (1) ◽  
pp. 17-25
Author(s):  
Suresh P. Tiwari

Understanding soil health impacts in relation to climate change is possible through the use of indicators which relate soil physical, chemical and biological. Major soil health indicators are governed by climate change. Selection of indicators within a minimum data depends on their sensitivity to management and climate changes, capacity to integrate and relate to other soil functions, ease of use, repeatability and cost of measurement. In this paper impact of soil health indicators including drivers for climate change; Carbon dioxide, nitrogen deposition, temperature, rainfall, soil structure, bulk density, rooting depth, soil surface cover, soil pH, electrical conductivity, available nutrients to plants, soil organic matter, soil carbon, potentially mineralisable Carbon and Nitrogen, soil respiration, soil microbial biomass, soil enzyme activities, genetic and functional biodiversity of soils on nematodes and selection of soil health key indicators are briefly discussed.


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