Nitrogen Deposition in Different Mediterranean Forest Types along the Eastern Adriatic Coast

Mediterranean forests along the eastern Adriatic coast have an important ecological role. However, few studies have been conducted on nitrogen deposition so far. To improve this knowledge, the main aims of our study were: (i) to estimate nitrogen inputs and determine differences among the four Mediterranean forests, (ii) to determine the seasonal behaviour of N deposition compounds, and (iii) to discuss the results in relation to forest type and precipitation. Measurements were carried out over a two-year period on four plots in two regions: holm oak and pubescent oak in Istria, Aleppo pine and black pine in Dalmatia. Bulk open field and throughfall deposition were sampled with continuously exposed collectors. Measurements, analyses and data validation of precipitation and N compounds were carried out. The results showed that the highest average monthly precipitation was recorded in the black pine plot and the lowest in the Aleppo pine plot. Nitrate and ammonia in conifer plots in throughfall samples were lower than in bulk open field samples, indicating possible retention by the tree canopy. The results revealed a higher amount of N deposition collected in broadleaved forests than in conifer forests indicating the washing out of N compounds previously deposited and accumulated in forest canopy. The chemistry of N deposition was strongly influenced by local and anthropogenic sources as well as neighbouring countries. Our results may fill the knowledge gap in understanding the influence of precipitation and seasonality of N compounds in different Mediterranean forest types along the eastern Adriatic coast.

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Short-Term N-Fertilization Differently Affects the Leaf and Leaf Litter Chemistry of the Dominant Species in a Mediterranean Forest under Drought Conditions

Forests ◽

10.3390/f12050605 ◽

2021 ◽

Vol 12 (5) ◽

pp. 605

Author(s):

Helena Vallicrosa ◽

Jordi Sardans ◽

Romà Ogaya ◽

Pere Roc Fernández ◽

Josep Peñuelas

Keyword(s):

Leaf Litter ◽

Dominant Species ◽

Isotope Analysis ◽

Mediterranean Ecosystems ◽

N Fertilization ◽

N Deposition ◽

Mediterranean Forest ◽

Short Term ◽

Species Response ◽

Drought Conditions

Nitrogen (N) deposition is a key driver of global change with significant effects on carbon (C) cycling, species fitness, and diversity; however, its effects on Mediterranean ecosystems are unclear. Here, we simulated N deposition in an N-fertilization experiment with 15N-labeled fertilizer in a montane evergreen Mediterranean holm oak forest, in central Catalonia, to quantify short-term impacts on leaf, leaf litter elemental composition, and resorption efficiency in three dominant species (Quercus ilex, Phillyrea latifolia, and Arbutus unedo). We found that even under drought conditions, 15N isotope analysis of leaf and leaf litter showed a rapid uptake of the added N, suggesting an N deficient ecosystem. Species responses to N fertilization varied, where A. unedo was unaffected and the responses in P. latifolia and Q. ilex were similar, albeit with contrasting magnitude. P. latifolia benefited the most from N fertilization under drought conditions of the experimental year. These differences in species response could indicate impacts on species fitness, competition, and abundance under increased N loads in Mediterranean forest ecosystems. Further research is needed to disentangle interactions between long-term N deposition and the drought predicted under future climate scenarios in Mediterranean ecosystems.

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Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts

Global Change Biology ◽

10.1111/j.1365-2486.2006.01104.x ◽

2006 ◽

Vol 12 (3) ◽

pp. 470-476 ◽

Cited By ~ 370

Author(s):

GARETH K. PHOENIX ◽

W. KEVIN HICKS ◽

STEVE CINDERBY ◽

JOHAN C. I. KUYLENSTIERNA ◽

WILLIAM D. STOCK ◽

...

Keyword(s):

Nitrogen Deposition ◽

N Deposition ◽

Global Perspective ◽

Atmospheric Nitrogen Deposition ◽

Biodiversity Hotspots ◽

Atmospheric Nitrogen

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Responses of Temperate Forests to Nitrogen Deposition: Testing the Explanatory Power of Modeled Deposition Datasets for Vegetation Gradients

Ecosystems ◽

10.1007/s10021-020-00579-4 ◽

2020 ◽

Author(s):

Marina Roth ◽

Hans-Gerhard Michiels ◽

Heike Puhlmann ◽

Carina Sucker ◽

Maria-Barbara Winter ◽

...

Keyword(s):

Nitrogen Deposition ◽

Nitrogen Availability ◽

Explanatory Power ◽

Context Dependency ◽

Forest Types ◽

Complex Situation ◽

Mixed Effect ◽

Study Region ◽

Vegetation Gradients ◽

Deposition Models

AbstractEutrophication due to increased nitrogen concentrations is known to alter species composition and threaten sensitive habitat types. The contribution of atmospheric nitrogen deposition to eutrophication is often difficult to determine. Various deposition models have been developed to estimate the amount of nitrogen deposited for both entire regions and different landscape surface types. The question arises whether the resulting deposition maps allow direct conclusions about the risk of eutrophication-related changes in the understory vegetation composition and diversity in nitrogen-sensitive forest ecosystems. We combined vegetation and soil data recorded across eutrophication gradients in ten oligo-mesotrophic forest types in southwest Germany with datasets from two different deposition models specifically fitted for forests in our study region. Altogether, 153 forest stands, with three sampling replicates each, were examined. Linear mixed-effect models and NMDS analyses revealed that other site factors, in particular the soil C/N ratio, soil pH and canopy cover, played a greater role in explaining vegetation gradients than nitrogen deposition. The latter only rarely had effects on species richness (positive), nitrophyte cover (positive or negative) and the cover of sensitive character species (negative). These effects varied depending on the deposition model used and the forest types examined. No effects of nitrogen deposition on average Ellenberg N values were found. The results reflect the complex situation in forests where nitrogen availability is not only influenced by deposition but also by nitrogen mineralization and retention which depend on soil type, pH and (micro)climate. This context dependency must be regarded when evaluating the effects of nitrogen deposition.

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Post‐fire restoration with contour‐felled log debris increases early recruitment of Spanish Black pine ( Pinus nigra Arn. ssp. salzmannii ) in Mediterranean forests

Restoration Ecology ◽

10.1111/rec.13338 ◽

2020 ◽

Author(s):

Manuel Esteban Lucas‐Borja ◽

John T. Van Stan ◽

Mehdi Heydari ◽

Reza Omidipour ◽

Francisco Rocha ◽

...

Keyword(s):

Pinus Nigra ◽

Mediterranean Forests ◽

Black Pine ◽

Early Recruitment

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Foliar Spectra and Traits of Bog Plants across Nitrogen Deposition Gradients

Remote Sensing ◽

10.3390/rs12152448 ◽

2020 ◽

Vol 12 (15) ◽

pp. 2448

Author(s):

Alizée Girard ◽

Anna K. Schweiger ◽

Alexis Carteron ◽

Margaret Kalacska ◽

Etienne Laliberté

Keyword(s):

Least Squares ◽

Nitrogen Deposition ◽

Partial Least Squares ◽

Plant Species ◽

Spectral Properties ◽

N Deposition ◽

Morphological Properties ◽

Dry Matter Content ◽

Foliar Traits

Bogs, as nutrient-poor ecosystems, are particularly sensitive to atmospheric nitrogen (N) deposition. Nitrogen deposition alters bog plant community composition and can limit their ability to sequester carbon (C). Spectroscopy is a promising approach for studying how N deposition affects bogs because of its ability to remotely determine changes in plant species composition in the long term as well as shorter-term changes in foliar chemistry. However, there is limited knowledge on the extent to which bog plants differ in their foliar spectral properties, how N deposition might affect those properties, and whether subtle inter- or intraspecific changes in foliar traits can be spectrally detected. The objective of the study was to assess the effect of N deposition on foliar traits and spectra. Using an integrating sphere fitted to a field spectrometer, we measured spectral properties of leaves from the four most common vascular plant species (Chamaedaphne calyculata, Kalmia angustifolia, Rhododendron groenlandicum and Eriophorum vaginatum) in three bogs in southern Québec and Ontario, Canada, exposed to different atmospheric N deposition levels, including one subjected to a 18-year N fertilization experiment. We also measured chemical and morphological properties of those leaves. We found detectable intraspecific changes in leaf structural traits and chemistry (namely chlorophyll b and N concentrations) with increasing N deposition and identified spectral regions that helped distinguish the site-specific populations within each species. Most of the variation in leaf spectral, chemical, and morphological properties was among species. As such, species had distinct spectral foliar signatures, allowing us to identify them with high accuracy with partial least squares discriminant analyses (PLSDA). Predictions of foliar traits from spectra using partial least squares regression (PLSR) were generally accurate, particularly for the concentrations of N and C, soluble C, leaf water, and dry matter content (<10% RMSEP). However, these multi-species PLSR models were not accurate within species, where the range of values was narrow. To improve the detection of short-term intraspecific changes in functional traits, models should be trained with more species-specific data. Our field study showing clear differences in foliar spectra and traits among species, and some within-species differences due to N deposition, suggest that spectroscopy is a promising approach for assessing long-term vegetation changes in bogs subject to atmospheric pollution.

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Responses of Carbon Dynamics to Nitrogen Deposition in Typical Freshwater Wetland of Sanjiang Plain

Journal of Chemistry ◽

10.1155/2014/603948 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Yang Wang ◽

Jingshuang Liu ◽

Longxue He ◽

Jingxin Dou ◽

Hongmei Zhao

Keyword(s):

Soil Carbon ◽

Nitrogen Deposition ◽

Carbon Dynamics ◽

N Deposition ◽

Sanjiang Plain ◽

Carbon Accumulation ◽

Total Biomass ◽

Soil System ◽

Carbon Fractions ◽

Soil Carbon Fractions

The effects of nitrogen deposition (N-deposition) on the carbon dynamics in typicalCalamagrostis angustifoliawetland of Sanjiang Plain were studied by a pot-culture experiment during two continuous plant growing seasons. Elevated atmospheric N-deposition caused significant increases in the aboveground net primary production and root biomass; moreover, a preferential partition of carbon to root was also observed. Different soil carbon fractions gained due to elevated N-deposition and their response intensities followed the sequence of labile carbon > dissolved organic carbon > microbial biomass carbon, and the interaction between N-deposition and flooded condition facilitated the release of different carbon fractions. Positive correlations were found between CO2and CH4fluxes and liable carbon contents with N-deposition, and flooded condition also tended to facilitate CH4fluxes and to inhibit the CO2fluxes with N-deposition. The increases in soil carbon fractions occurring in the nitrogen treatments were significantly correlated with increases in root, aboveground parts, total biomass, and their carbon uptake. Our results suggested that N-deposition could enhance the contents of active carbon fractions in soil system and carbon accumulation in plant of the freshwater wetlands.

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Preference by Donkeys and Goats among Five Mediterranean Forest Species: Implications for Reducing Fire Hazard

Animals ◽

10.3390/ani10081302 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1302

Author(s):

Jordi Bartolomé ◽

Jordi Miró ◽

Xavier Panadès ◽

Maria José Broncano ◽

Josefina Plaixats ◽

...

Keyword(s):

Forest Fires ◽

Pinus Halepensis ◽

Fire Hazard ◽

Mediterranean Forest ◽

Mediterranean Forests ◽

Forest Species ◽

Rubus Ulmifolius ◽

Key Species ◽

The Mediterranean ◽

Cafeteria Test

During the second half of the 20th century, European countries experienced an increase in their forest area due to the global change. Consequently, there has been an increase in large forest fires, mainly in the Mediterranean basin, and this has forced the development of several types of prevention programs. One of them is the control of the understory by livestock. In this sense, browsing with a combination of donkeys and goats could be a good option, as both animals usually feed on forest species. However, little is known about their preferences for the key species of the Mediterranean forest. Using a cafeteria test, the preferences and consumption of both animals have been determined for five typical species of the Mediterranean forest, such as Quercus ilex, Pinus halepensis, Phillyrea latifolia, Rubus ulmifolius, and Brachypodium retusum. Results showed that donkeys and goats could act complementarily in the reduction of the fuel biomass of forests. Donkeys appear to act more on fine fuel, such as B. retusum, and goats on the more pyrophyte species, in this case P. halepensis. In addition, given that donkeys are at severe risk of extinction in Europe, this role of providing ecosystem services could contribute to their conservation. Despite this study only showing that goats and donkeys would consume all five presented plant species and that there are some differences in consumption during a short-term test, it constitutes a useful first step for conservation and fire prevention in the Mediterranean forests.

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Forest vulnerability and tree mortality in the Mediterranean: Impacts and Opportunities

10.5194/egusphere-egu2020-2522 ◽

2020 ◽

Author(s):

Tamir Klein

Keyword(s):

Tree Mortality ◽

Niche Partitioning ◽

Common Garden ◽

Fruit Trees ◽

Forest Tree ◽

Aleppo Pine ◽

Mediterranean Forests ◽

Mortality Pattern ◽

Key Species ◽

The Mediterranean

The Mediterranean basin is a mosaic of human and natural landscapes, many of which are important forests and woodlands. Among global biomes, it has been under the longest anthropogenic stress, and today, in addition to the ongoing warming, it experiences drying. In my talk I will give examples from new research on the impacts of these processes on Mediterranean forests, as well as opportunities for increasing their sustainability under intensifying change.Aleppo pine is perhaps the single most important forest tree species for the region, and has been grown for decades in common garden plots of provenances from around the region. Forest scientists from Spain, Italy, Greece and Israel, teamed up to synthesize the results of these provenance trials. Together, we produced the temperature and precipitation growth sensitivity profiles for Aleppo pine. Next, these profiles were applied on future climate maps, to show the potential expansion of this key species northward, as well as its extinction in many southern locations. In a seven decades-long tree mortality study across Israel, this mortality pattern is already occurring, driven by hotter and longer drought periods.My current research is focused on finding new avenues to ensure the long-term existence of forests and trees in the Mediterranean. Examples include: (1) Mixed forests, with native broadleaf and conifer species coexisting, have high resilience, thanks to interspecific niche partitioning; (2) Native fruit trees have higher drought resistance than their cultivated relatives, and should be protected and integrated into local agriculture; (3) Native savannah trees from the southern fringes of the region are becoming more important, and offer new resilience strategies; and (4) Variations among Aleppo pine ecotypes give hope for the future suitability of this species across the Mediterranean.

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Modelling Nitrogen Deposition on a Local Scale—A Review of the Current State of the Art

Environmental Chemistry ◽

10.1071/en06038 ◽

2006 ◽

Vol 3 (5) ◽

pp. 317 ◽

Cited By ~ 60

Author(s):

Ole Hertel ◽

Carsten Ambelas Skjøth ◽

Per Løfstrøm ◽

Camilla Geels ◽

Lise Marie Frohn ◽

...

Keyword(s):

Nitrogen Deposition ◽

Environmental Assessment ◽

State Of The Art ◽

N Deposition ◽

Model Systems ◽

Special Focus ◽

Ammonia Emissions ◽

High Nitrogen ◽

Current State ◽

The Impact

Abstract. Local ammonia emissions from agricultural activities are often associated with high nitrogen deposition in the close vicinity of the sources. High nitrogen (N) inputs may significantly affect the local ecosystems. Over a longer term, high loads may change the composition of the ecosystems, leading to a general decrease in local biodiversity. In Europe there is currently a significant focus on the impact of atmospheric N load on local ecosystems among environmental managers and policy makers. Model tools designed for application in N deposition assessment and aimed for use in the regulation of anthropogenic nitrogen emissions are, therefore, under development in many European countries. The aim of this paper is to present a review of the current understanding and modelling parameterizations of atmospheric N deposition. A special focus is on the development of operational tools for use in environmental assessment and regulation related to agricultural ammonia emissions. For the often large number of environmental impact assessments needed to be carried out by local environmental managers there is, furthermore, a need for simple and fast model systems. These systems must capture the most important aspects of dispersion and deposition of N in the nearby environment of farms with animal production. The paper includes a discussion on the demands on the models applied in environmental assessment and regulation and how these demands are fulfilled in current state-of-the-art models.

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Nitrogen deposition: how important is it for global terrestrial carbon uptake?

Biogeosciences Discussions ◽

10.5194/bgd-10-11077-2013 ◽

2013 ◽

Vol 10 (7) ◽

pp. 11077-11109 ◽

Cited By ~ 1

Author(s):

G. Bala ◽

N. Devaraju ◽

R. K. Chaturvedi ◽

K. Caldeira ◽

R. Nemani

Keyword(s):

Nitrogen Deposition ◽

Carbon Storage ◽

Climate Warming ◽

N Deposition ◽

Carbon Uptake ◽

Terrestrial Carbon ◽

Co2 Fertilization ◽

Current Increase ◽

Community Land Model ◽

Global Mean

Abstract. Global carbon budget studies indicate that the terrestrial ecosystems have remained a~large sink for carbon despite widespread deforestation activities. CO2-fertilization, N deposition and re-growth of mid-latitude forests are believed to be key drivers for land carbon uptake. In this study, we assess the importance of N deposition by performing idealized near-equilibrium simulations using the Community Land Model 4.0 (CLM4). In our equilibrium simulations, only 12–17% of the deposited Nitrogen is assimilated into the ecosystem and the corresponding carbon uptake can be inferred from a C : N ratio of 20:1. We calculate the sensitivity of the terrestrial biosphere for CO2-fertilization, climate warming and N deposition as changes in total ecosystem carbon for unit changes in global mean atmospheric CO2 concentration, global mean temperature and Tera grams of Nitrogen deposition per year, respectively. Based on these sensitivities, it is estimated that about 242 PgC could have been taken up by land due to the CO2 fertilization effect and an additional 175 PgC taken up as a result of the increased N deposition since the pre-industrial period. Because of climate warming, terrestrial ecosystem could have lost about 152 PgC during the same period. Therefore, since preindustrial times terrestrial carbon losses due to warming may have been approximately compensated by effects of increased N deposition, whereas the effect of CO2-fertilization is approximately indicative of the current increase in terrestrial carbon stock. Our simulations also suggest that the sensitivity of carbon storage to increased N deposition decreases beyond current levels, indicating climate warming effects on carbon storage may overwhelm N deposition effects in the future.

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