Holding approximately 89,000 Tg of organic carbon, tropical peatlands are one of the largest pedological sinks of carbon (Page et al., 2011). Waterlogged conditions in undisturbed peatlands reduce heterotrophic respiration and provide environments in which organic matter accumulates (Moore et al., 2013). However, from 1990 to 2010, the forest cover in the peatlands of South East Asia fell from 77% to 36%; at this rate of decline, all of the undisturbed peatlands are likely to have disappeared by 2030 (Li et al., 2007; Koh et al., 2011; Miettinen et al., 2011). Land-use changes in these ecosystems can have important consequences for carbon (C) budgets (Page et al., 2002; Hooijer et al., 2010). Recently a number of studies have been carried out on tropical peatlands (e.g. Couwenberg et al., 2010; Hergoualc'h and Verchot, 2011; Hirano et al., 2012; Jauhiainen et al., 2005, 2012; Li et al., 2007; Melling et al., 2005; Page et al., 2009), but some parts of the C budget are yet to be quantified. In order to fill these gaps in our knowledge, the goal of this work was to assess heterotrophic and total soil respiration, litterfall, litter decomposition and evaluate peat properties in an intact peat swamp forest, a transitional logged drained forest and an oil palm plantation located on the same alluvial peat plain. This in-situ research lasted two years, and heterotrophic and total soil respiration were separated using the trenching method. Our results from the carbon dioxide flux monitoring in the three land uses showed that the trenched plots provided a good proxy for heterotrophic respiration. The annual integrated total soil respiration was lower in the intact and drained forest than in the oil palm plantation, at 20.2 ±3.4, 18.7 ±1.1 and 26.4 ±1.7 Mg C ha-1 y-1, respectively. A similar pattern was seen in the heterotrophic respiration for the same land uses, 9.6 ±7.7, 15.7 ±1.0 and 22.9 ±2.0 Mg C ha-1 y-1, respectively. When extrapolated to the landscape, the percentage of heterotrophic 4 respiration appeared to have significantly increased following drainage, even before the conversion to oil palm, with percentages of 47.6 ±10.1, 83.9 ±7.3, 86.6 ±1.9 for intact forest, drained forest and oil palm plantation, respectively. The average litterfall in the three land uses was not significantly different, at 26.3 ±4.1, 23.2 ±4.2 and 18.6 ±3.5 kg dry litter ha-1 d-1 respectively. Overall, the C fluxes results produced in this thesis point towards a negative C balance (i.e. net ecosystem loss of C) for the drained forest, a pronounced negative C balance for the oil palm plantation and a near neutral balance for the intact forest. Other relevant findings in the study were: (1) the impacts of N fertilizer application in the oil palm plantation lasted only a few days and were unlikely to have significant consequences on the annual C budget; (2) concerns over the diurnal variability of carbon dioxide fluxes are not particularly pertinent in these tropical peatlands; and (3) the principal soil property affected by drainage and land-use change was the abundance of logs in the soil. In summary, the results produced in this thesis represent noteworthy data about the C budget and C dynamics in tropical peatlands and will help decision making by policy makers and land managers for sustainable use of these ecosystems.

Orientador: Iraê Amaral Guerrini / Banca: Roberto Lyra Vilas Bôas / Banca: Cássio Hamilton Abreu Junior / Resumo: O uso de lodo de esgoto como fertilizante orgânico, além de ser uma alternativa para a destinação final desse resíduo, pode melhorar as propriedades do solo, já que é um material rico em nutrientes e matéria orgânica, podendo favorecer o desenvolvimento das plantas. O objetivo deste trabalho foi verificar o efeito da aplicação de doses de lodo de esgoto e composto de lodo no desenvolvimento inicial de um híbrido Eucalyptus. grandis x E. urophylla. O experimento foi conduzido em estufa plástica, sem controle ambiental, e foi composto por 48 vasos contendo 50L de Latossolo textura média. Trata-se de um experimento fatorial, com dois fatores: fertilizante orgânico (lodo de esgoto e composto de lodo - ambos sem adição de calcário) e dose (10, 20, 30, 40 e 50 Mg ha-¹ + K), além de dois tratamentos adicionais (controle e adubação inorgânica indicada para a espécie). Cada tratamento foi composto por quatro repetições. A altura, diâmetro do colo e índice de cor verde foram medidos mensalmente, durante seis meses e a área foliar, massa de matéria seca, nutrição das plantas e fertilidade do solo foram avaliadas ao final do experimento (seis meses após plantio). Os dados foram submetidos à análise de variância, complementado com testes de comparações múltiplas e com ajustes de modelos de regressão polinomial para avaliar o efeito das doses, ao nível de 5% de significância. Tanto o lodo de esgoto, como o composto, nas doses de 40 e 50 Mg ha-1, forneceram quantidades de nutrientes, às pla... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of sewage sludge as an organic fertilizer, besides being an alternative for the final disposal of such waste, it may improve the soil properties, since it is a material rich in nutrients and organic matter, which may favor the development of plants. The objective of this work was to verify the effect of doses of sewage sludge and sludge compost in the initial development of a hybrid of Eucalyptus grandis x Eucalyptus urophylla. The experiment was conducted in plastic greenhouse, without environment control, and was composed of 48 vessels containing 50L of dystrophic medium texture. It is a factorial experiment with two factors: organic fertilizer (sewage sludge and sludge compost - both without limestone) and dose (10, 20, 30, 40 and 50 Mg ha-¹ + K), plus two additional treatments (absolute control and mineral fertilization indicated to the species). Each treatment was composed by four repetitions. The height, stem diameter and index of green color were measured monthly, during six months and leaf area, dry matter mass, plant nutrition and soil fertilizer were evaluated at the end of the experiment. The data were subjected to analysis of variance, complemented with tests of multiple comparisons and adjustments of polynomial regression models to evaluate the effect of doses, at 5% level of significance. Both sewage sludge and sludge compost, in the doses of 40 e 50 Mg ha-1, provided quantities of nutrients to plants and soil, higher than absolute control and greater than or equal to inorganic fertilization but never lower than it, what explain the improvements in the soil fertilizer and in the plants development like higher height, diameter, leaf area and production of dry matter mass when they received these quantities of both of organic fertilizers. So, the sludge and the sludge compost, when used in doses of 40 and 50 Mg ha-1 provided enough quantities of nutrients for plants of Eucalyptus to have... / Mestre

Diploma thesis is aimed at evaluation of soil organic carbon dynamic and humic substances quality in monoculture of spring barley and Norfolk crop rotation system. Further we followed the influence of different soil tillage system (minimalization and conventional tillage) on to humus and humic substances dynamic. Gleiyc Fluvisol was classified and observed during 2017 – 2018 within field long term experiments of Mendel University in Brno at locality Žabčice. Measured data set was evaluated using program StatisticaCZ12, software (StatSoft software Inc., Tulsa, Oklahoma, USA). Obtained results shown that statistically significant differences between Norfolk and monoculture were in following parameters: organic carbon content, humus content and humic substances content. Higher values were in Norfolk crop rotation system.

Orientador: Juliano Carlos Calonego / Banca: Alexandrius de Moraes Barbosa / Banca: Gustavo Pavan Mateus / Banca: Kleber Pereira Lanças / Banca: João Paulo Gonsiorkiewicz Rigon / Resumo: Com o advento de sistemas de direcionamento via satélite, onde é possível controlar tanto o tráfego das máquinas, quanto planejar e realizar o preparo e a sulcação apenas em locais pré-definidos, onde não haverá tráfego de máquinas, novos sistemas de preparo do solo têm surgido. O preparo profundo cateirizado consiste em preparar, corrigir e adubar o terreno somente na área onde serão confeccionados os sulcos de plantio, ou seja, somente na zona de crescimento das plantas, limitando a compactação em área específica de trânsito de maquinários. Porém, ainda é pouco conhecido os efeitos desse sistema de preparo na estrutura do solo e produtividade da cana-de-açúcar. Objetivou-se com esse trabalho avaliar, em área de cultivo de cana-de-açúcar, o efeito da calagem e do preparo do solo, na produtividade de colmos, nos atributos físicos do solo e na qualidade da matéria orgânica. Para isso, foram realizados dois experimentos, sendo um em solo de textura argilosa (Nitossolo Vermelho) e outro em solo de textura franco-arenosa (Latossolo Vermelho-Amarelo), utilizando-se o delineamento experimental de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos por: Preparo Convencional (PC) sem aplicação de calcário, PC com aplicação de calcário, Preparo Profundo (PP) sem aplicação de calcário, e PP com aplicação de calcário. Foram avaliados os atributos físicos, carbono orgânico total (COT), fracionamento físico da MOS, biomassa microbiana do solo e produtividade de c... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The advent of satellite guidance systems promoted the emergence of the new tillage systems due to the possibility to control machine traffic, as well as to plan and prepare and furrow only in pre-defined locations where there will be no machine traffic. The deep soil tillage in the plant growth zone consists in the descompactation, liming and fertilization only in the area where the planting furrows will be made, ie only in the plant growth zone, limiting soil compaction in a specific machine traffic zone. However, the effects of this tillage system on soil structure and sugarcane yield are still poorly known.The aim of this experiment was to assess the effect of liming and soil tillage (deep tillage banded and conventional tillage), in the area of sugarcane production, on stalks yield, soil physical attributes and soil organic matter quality. For this, two experiments were carried out, one in clayey soil and the other in sandy soil, using a randomized blocks experimental design with four replications. The treatments were constituted by: conventional preparation (PC) without application of limestone, PC with limestone application, deep preparation (PP) without application of limestone, and PP with application of limestone. The physical attributes, total organic carbono, physical fractionation of organic matter, soil microbial biomass and stalk yield were evaluated. In both experiments, the soil tillage reduced the soil organic carbon in the plant growth zone, up to 20 cm depth, independent of the limestone application, and when PC with liming was carried out with higher carbon impact associated with minerals. The ability of C immobilization by soil microbial biomass was inversely proportional to soil management intensity, with higher levels of microbial biomass carbon and microbial quotient in the conventional tillage system, independent of the limestone application to the clayey soil, and with ... / Doutor

The subject of this research is a level of aberration of soil on selected sites in the land register of Vlkov u Osové Bítýšky village. During a Complex soil survey (1967/1968) were collected three samples In 1966 and 1967, in this territory. From these samples were selected data from texture analysis pH and humus. The old soil sampling sites were re-localized and from the very spots, new samples were taken from the depth of approximately 75 cm in order to gain current results. These new samples were analyzed in a laboratory and these results were compared with the 50 years old ones. This allowed us to evaluate changes in soil on the selected sites.

No description available.

La generación de residuos sólidos orgánicos es un problema ambiental que afecta a la población, razón por la cual muchas municipalidades realizan programas de segregación para disminuir su impacto negativo, como lo es el distrito de Reque, el cual generó en el año 2020 un total de 4 845 128, 26 kg de residuos, de los cuales el 51,57%, es decir, 2 498 632,64 kg, fueron materia orgánica, gracias a esta materia se puede obtener humus, un producto que es considerado uno de los abonos orgánicos que más nutrientes aporta a la tierra y que es usado por los productores agrícolas orgánicos del Perú. Se determinó como mercado objetivo a los productores orgánicos a nivel nacional, cuya demanda fue de 10 868,49 toneladas, tomando como demanda del proyecto el 18,09%, para el año 2027, representando en este último año una producción de humus de 78 658 sacos en presentación de sacos de 25 kg. Se estableció la ubicación de la planta en el distrito de Reque con un área total de 13 720,41 m2. La inversión tangible fue de S/.2 562 189, 41 con una inversión diferida de S/.4 559, haciendo una inversión total de S/.3 253 484,08 la cual será inversión propia sin financiamiento. Se obtuvo un VAN de S/. 1 731 317,68 y un TIR de 20,99%, el costo beneficio de la propuesta fue de 2,06, lo que significa que por cada sol invertido se obtiene 1,06 soles de ganancia.

No description available.

In einem für das Erzgebirge (Sachsen, Südostdeutschland) typischen Wirtschaftswald aus ca. 60-jähriger Fichte (Picea abies [L.] KARST.), in den Sand-Birken (Betula pendula Roth) eingemischt sind, sollte die Wirkung der Baumartenmischung auf den Oberbodenzustand erfasst und bewertet werden. Die Befunde stammen aus einem Bestand, der sowohl hinsichtlich der Altersstruktur, des Bodentyps als auch der Stoffeinträge und der Kalkung für das Erzgebirge repräsentativ ist. Analysiert wurden photosynthetisch aktive Strahlung, Bodenvegetation, Streumenge und -verteilung, Dynamik der Streuzersetzung, Humuskörpermorphologie sowie chemische und mikrobiologische Oberbodeneigenschaften. Dabei fand ein einzelbaumweiser Ansatz in Kopplung mit Transekten Anwendung. Es wurden eindeutige Effekte durch einzelbaumweise eingemischte Birken nachgewiesen. Mit Hilfe des Einzelbaumansatzes und davon ausgehenden Transekten wurden reine Fichtenbereiche und Mischungsbereiche untersucht. Zusätzlich wurden für die Auswertung drei Straten gebildet. Die Zuordnung dafür war die folgende: Probepunkte unter der Birkenkrone ergaben das Birken-Stratum, Probepunkte unter der Fichte das Fichten-Stratum und Probepunkte im Übergangsbereich zwischen Birke und Fichte das Fichten-Birken-Stratum. Im Bereich der Birkenkronen waren überwiegend höhere Strahlungswerte festzustellen als unter den Fichtenkronen. Gezeigt wurde aber auch, dass die höheren Strahlungswerte, die unter den Birkenkronen auftraten, auch in lichteren bzw. lückigeren Partien des reinen Fichtenbestandes zu finden waren. Die Sippenanzahl der Bodenvegetation erhöhte sich sowohl unter reiner Fichte als auch in Mischung von Fichte und Birke vor allem mit zunehmender Annäherung zum Kronenrand. Insgesamt waren aber bei der Mischung von Fichte und Birke ähnlich hohe Sippenanzahlen wie im reinen Fichtenbereich zu finden. Allerdings gab es Sippen, die nur auf einer der beiden Flächen auftraten. Es waren höhere Deckungsgrade bei der Mischung von Fichte und Birke im Vergleich zur reinen Fichte sichtbar. Die Befunde der Streusammler ließen erkennen, dass in einer Entfernung von > 16 m vom Birkenstamm kaum noch Birkenstreu auftrat. Nennenswerte Trockenflussdichten wurden nur in einem Radius von 10 m festgestellt. In diesem Bereich ist ein Effekt der Birkenstreu auf die Oberbodeneigenschaften zu erwarten. Die Gesamttrockenmasse einer relativ vitalen Birke mit rund 38 cm Brusthöhendurchmesser betrug im Untersu-chungsjahr rund 8 kg. Die Modellierung unter Hinzunahme weniger vitaler Birken reduzierte die Gesamttrockenmasse auf 6,3 kg. Der Massenverlust der Birkenblätter in den Litter-Bags war in allen drei Straten bei der Mischung der Birkenblätter mit Fichtennadeln im Verhältnis 5:1 am größten. Bei den Fichtennadeln zeigten sich die höchsten Trockenmassenverluste in den reinen Nadel-Litter-Bags. Die Litter-Bags unter der Birkenkrone wiesen für alle Varianten die beste Zersetzung der Birkenblätter und der Fichtennadeln auf. Die C/N-Verhältnisse der Streu ließen keine eindeutigen positiven Effekte der Birkenkrone erkennen. Sie waren aber bei den Birkenblättern in allen Varianten, in allen Straten und zu allen Terminen deutlich enger als die der Fichtennadeln. Desweiteren war der Abfall der C/N-Kurven bei den Birkenblättern steiler als bei den Fichtennadeln. Die Mächtigkeit des Of-Horizontes wies sowohl in der Mischsituation als auch in der reinen Fichtenfläche deutlichere räumliche Muster auf als im Oh-Horizont. Im Of waren dadurch deutliche, vom Einzelbaum abhängige, Muster zu erkennen. Die höchsten Mächtigkeiten traten in Stammnähe auf. Die größten Gesamtmächtigkeiten existierten unter reiner Fichte. Beim Vergleich der Mächtigkeiten in den Straten war in der Of-Lage vor allem das Birken-Stratum signifikant verschieden vom Fichten-Stratum. Für die Oh-Mächtigkeit und somit auch die Gesamtmächtigkeit zeigte zusätzlich das Fichten-Birken-Stratum signifikante Unterschiede im Vergleich zum Birken-Stratum. Als Humusform trat der rohhumusartige Moder auf. Dabei überwog im Fichtenstratum der feinhumusreiche rohhumusartige Moder, im Fichten-Birken-Stratum und im Birken-Stratum dagegen der feinhumusarme rohhumusartige Moder. Signifikante Unterschiede zwischen Straten konnten in der Of-Lage für den pH-Wert, Cges-Vorrat, Ccarbonat-Gehalt, Nges-Gehalt, Nges-Vorrat, und den metabolischen Quotienten erfasst werden. In der Oh-Lage waren es die nachstehenden Oberbo-deneigenschaften: Corg/N-Verhältnis, Cges-Gehalt, Nmik-Gehalt, Cmik/Nmik-Verhältnis, Basalatmungsaktivität, sowie der metabolische Quotient, die sich zwischen den Straten signifikant unterschieden. Im A-Horizont zeigten sich signifikante Unterschiede der Straten beim Corg/N-Verhältnis, Cges-Gehalt, Ccabonat-Gehalt, Corg-Gehalt sowie dem Nges-Vorrat. Mit Hilfe der multivariaten Ordination (mit verschiedenen Elementgehalten und pH-Werten) ist die Stratenbildung erneut bestätigt worden. Dabei hatten die Elemente C, Mg, Ca und N den größten Einfluss. Die Auswertung der Daten der effektiven Kationenaustauschkapazität ließ vor allem für den A-Horizont Unterschiede zwischen den Straten erkennen. Dabei war die Akeff im Fichtenstratum am kleinsten und der prozentuale Anteil der sauren Kationen an der Akeff am größten. Die höchste Akeff besaß das Birken-Stratum. Eine Reihe der untersuchten Größen ließen eindeutige Baumarteneffekte erkennen. Alles in allem wurde der Nachweis erbracht, dass die Effekte in dem Bereich zu finden sind, der durch die Laubstreu der Birken geprägt ist. Bei den Oberbodeneigenschaften wurden keine Veränderungen an Punkten, die mehr als 10 m vom Birkenstamm entfernt waren, festgestellt. Aus den Ergebnissen war abzuleiten, dass für ähnliche Bedingungen wie im Untersuchungsbestand ein Mischungsanteil der Birke von mindestens 10 % zu empfehlen ist. Die Ergebnisse sind aber durch zukünftige Forschung noch zu verifizieren. Dafür sollten vor allem die Produktionsziele und die waldbaulichen Behandlungskonzepte für Mischbestände aus Fichte und Birke in Deutschland erneut konkretisiert werden. Um dafür eindeutige ökologische und ökonomische Kriterien festlegen zu können, wird eine Zusammenführung wichtiger Ergebnisse aus den verschiedenen forstlichen Forschungsbereichen (z. B. Standortskunde, Vegetationskunde, Waldwachstumskunde, Ökonomie, Zoologie, Waldbau) empfohlen. / In a typical managed forest of the Ore Mountains (Saxony, SE Germany), consisting of 60 years old Norway spruce (Picea abies [L.] KARST.) admixed with silver birches (Betula pendula Roth) the impact of the admixture on topsoil properties was quantified and evaluated. This study was conducted in a stand which is representative for the Ore Mountains regarding the soil type, deposition and liming. Photosynthetic active radiation, the layer of herbs and mosses, the mass and distribution of the litter fall, the dynamics of litter decom-position, and morphology of the humus layer as well as the chemical and microbiological topsoil properties were all analyzed. The study was based on a single-tree-approach where samples were collected along transects from selected sample trees of birch and spruce. Transects were established within areas of pure spruce as well as within areas of spruce and birch mixture. Three different strata were defined based on the situation of the examined points in relation to the crowns of birch and spruce: the birch stratum, the spruce stratum and the spruce-birch stratum with measurements from underneath the crowns of birches, spruces and the transition area between spruce and birch crowns, respectively. Higher photosynthetic active radiation values were detected in the area underneath the crowns of birch crowns in comparison with the area underneath the crowns of spruce. Higher values of photosynthetic active radiation were also registered within areas of light foliage and in gaps in the pure spruce stand. The number of ground vegetation species underneath pure spruce and in the mixture of spruce and birch was negatively correlated with the distance to the crown edge. But altogether the same number of ground vegetation species was found in the mixed stand and in the pure spruce stand. A few species were, however, specific for each stand type. A higher coverage of ground vegetation was found in the mixture of spruce and birch in comparison to the pure spruce. The results of the litter traps show marginal densities of birch leaves at a distance of more than 16 m from the birch stem. The majority of the dry flux density was found within a radius of 10 m around the birch stem. Within this area an effect of the birch litter on top soil properties was expected. The whole dry litter mass was measured in the study time of a relative vital birch with a diameter at breast high of ca. 38 cm and was ca. 8 kg. Modeling the amount of litter for birches with lower vitality indicated a dry litter mass of 6.3 kg. The mass lost of the birch leaves in the litter bags was in each stratum the highest at a ratio of 5 to 1 of birch leaves to spruce needles. The greatest loss of dry mass for spruce needles was registered in litter-bags with pure needles. The litter-bags under the birch crowns exhibited the best decomposition rate of birch leaves and spruce needles for all variants. The C/N-ratios of the litter showed no clear positive effects of the birch crown. But they were clearly smaller for the birch leaves in contrast to the spruce needles in all variants, in each stratum and at all dates. Furthermore the C/N-curves drop away more for the birch leaves in contrast to the spruce needles. The thickness of the Of-horizon in contrast to the Oh-horizon showed clear spatial patterns for the mixed situation and the pure spruce area. Thus in the Of-horizon a clear spatial pattern in connection to the single tree was apparent. The highest thickness was found close to the stem. The highest total thickness of the Of- and Oh-horizon was found underneath the pure spruce stand. When comparing the thickness of the humus layers between the stratums, significant differences where found for the Of-layer between the birch stratum and the spruce stratum. In addition, for the thickness of the Oh-layer as well as for the total thickness of all layers, significant differences were observed between the spruce-birch stratum and the birch stratum. The humus form was a mor-like moder. In the spruce stratum more fine-humus-rich variants of the mor-like moder was found, in the spruce-birch stratum and in the birch stratum it was more fine-humus-poor variants of the mor-like moder. Significant differences between the stratums in the Of-layer were found with respect to acidification, the pool of Ctot and Ntot, the content of Ccarbonat and Ntot and the metabolic quotient. For the Oh-layer significant differences between the stratums were found for the ratio of Corg and N, the content of Ctot and Nmic, the ratio of Cmic and Nmic, the basal respiration activity and the metabolic quotient. In the A-horizon significant differences between the stratums were found for the ration of Corg and N, the content of Ctot, Ccarbonat and Corg and the pool of Ntot. The results of multivariate ordination confirm the formation of stratums again. Thereby the contents of C, Mg, Ca and N had the greatest influence. The data analysis of the effective cation exchange capacity (ECEC) showed differences between the stratums mainly for the A horizon. In the spruce stratum the ECEC was lowest and the percentage of acid cations at the ECEC was greatest. The highest ECEC was in the birch stratum. Different results showed clear tree effects. These were only found in areas, which are influenced by birch leaves. In this study, a minimum tree admixture of 10% was required before an impact on the ground conditions of the whole stand was observed. Therefore, based on the results of this study, an admixture of birch of 10% is recommended. These results however must be verified through future research. These findings can be used to assist in meeting the goals of silvicultural management for mixed spruce and birch forests in Germany. Definition of explicit ecological and economic criteria created from a combination of results from different forest research sectors (e. g. Site ecology, Vegetation science, Forest Growth, Economy, Zoology, Silviculture) is recommended.

Les hydrocarbures aromatiques polycycliques (HAP) constituent un groupe de polluants organiques persistants (POP). Ils sont produits par la combustion incomplète de la matière organique et peuvent être transférés sur de longues distances. Leur nature organique et hydrophobe leur confère une affinité vis-à-vis des surfaces lipidiques et des compartiments contenant de la matière organiques. Ils peuvent donc s’adsorber sur les matrices végétales et sur la matière organique des sols. La canopée, du fait de sa rugosité aérodynamique importante, constitue un puits important de HAP. Dans cette étude, nous avons suivi l’évolution de la concentration en HAP, sur une période de 20 ans (de 1993 à 2011), dans la végétation (feuilles/aiguilles), les couches organiques (OL, OF et OH) et les couches organo-minérales (0 – 10 cm, 10 – 20 cm et 20 - 40 cm) des sites forestiers français suivis par le réseau RENECOFOR (Réseau National de suivi à long terme des ECOsystèmes FORestiers).14 sites répartis sur tout le territoire français ont été choisis selon des caractéristiques différentes (type de l’essence forestière, climat, altitude, latitude, longitude, type d’humus forestier, contenu en carbone organique, etc.). Ainsi, 14 HAP considérés comme prioritaires par l’agence de protection de l’environnement des Etats-Unis (US-EPA) ont été quantifiés.Cette étude a mis en évidence l’efficacité de la végétation dans l’enregistrement de l’historique de la qualité de l’air des sites forestiers. Une baisse générale de la concentration en HAP dans la végétation et dans l’atmosphère pendant les 20 dernières années a été constatée. La végétation joue le rôle d’une pompe qui accumule les HAP et les transferts vers les sols forestiers. Le contenu en carbone organique semble être le paramètre contrôlant l’accumulation des HAP dans les sols forestiers. Ainsi, la dynamique des HAP entre les différents compartiments forestiers semble dépendre de leurs propriétés physico-chimiques et de leur capacité à subir des mécanismes de dissipation (lixiviation, dégradation, etc). Enfin, cette étude montre que les couches organo-minérales des sols forestiers constituent un puits plus important de HAP (légers, intermédiaires et lourds) que la végétation et les couches organiques dans l’écosystème forestier. / Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants (POPs). They are produced by incomplete combustion of organic matter and can be transported over long distances in the atmosphere. Because of their organic and hydrophobic nature they have a strong affinity for lipid surfaces and compartments containing organic matter. They can therefore be adsorbed on the plant matrices and on the organic matter of the soils. The canopy, due to its important aerodynamic roughness, constitutes an important sink for PAHs.In this study, we have monitored the evolution of PAHs concentrations over a period of 20 years (from 1993 to 2011) in 3 compartments of the forest ecosystem: vegetation (leaves / needles), organic layers (OL, OF and OH) and organo-mineral layers (0-10 cm, 10-20 cm and 20-40 cm) of French forest sites monitored by the RENECOFOR network (National Network for Long-term FOrest ECOsystem Monitoring).4 sites distributed throughout France were selected according to different characteristics (type of forest species, climate, altitude, latitude, longitude, type of forest humus, organic carbon content, etc.). Thus, 14 PAHs, considered as priority pollutants by the United States Environmental Protection Agency (U.S. EPA), were quantified.This study highlights the efficiency of vegetation in registering the history of air quality at forest sites. A general decrease in the concentration of PAHs in vegetation and in the atmosphere over the past 20 years has been observed.Vegetation plays the role of a pump that accumulates PAHs and transfers them to forest soils. Organic carbon content appears to be the most important parameter controlling PAHs accumulation in forest soils. Thus, PAHs transfer between the different forest compartments appears to depend on their physico-chemical properties and their ability to undergo dissipation mechanisms (leaching, degradation, etc.).Finally, this study shows that the organo-mineral layers of forest soils constitute a more important sink of (light, intermediate and heavy) PAHs than vegetation and organic layers in the forest ecosystem.