Sabine Braun

Institut für Angewandte Pflanzenbiologie | IAP

Plain Language Summary In the middle of a hot and dry summer, we often think that a large rain event can “rescue” a forest from drought. However, it is not clear whether trees can or do consistently use the water from summer rains. A growing body of research indicates that over the course of the summer growing season, trees take up significant amou...

Langzeituntersuchungen der Bodenlösung aus der Interkantonalen Walddauerbeobachtung zeigen eine deutliche Zunahme der Versauerung von Waldböden.

The critical level of ozone flux for forest trees is based entirely on biomass data from fumigation experiments with saplings, mostly in open-top chambers. Extrapolation to mature forests asks, therefore, for validation, which may be performed by epidemiological data analysis. This requires a multivariable regression analysis with a number of covar...

Die Nährstoffausstattung des Oberbodens ist für die Vitalität und das Wachstum der Waldbäume entscheidend. Die seit Jahrzehnten hohen Stickstoffeinträge in die Wälder führen zu Eutrophierung. Gleichzeitig verarmt der Boden an wichtigen Nährstoffkationen und versauert. Über die sich daraus ergebenden möglichen Engpässe in der Nährstoffversorgung für...

Radial stem growth dynamics at seasonal resolution are essential to understand how forests respond to climate change. We studied daily radial growth of 160 individuals of seven temperate tree species at 47 sites across Switzerland over 8 years. Growth of all species peaked in the early part of the growth season and commenced shortly before the summ...

Programme d’observation permanente intercantonal des forêts des cantons d’AG, BE, BL, BS, GR, SO, TG, ZH , des offices de l´environnement de la Suisse centrale et de l’OFEV. Rapport allemand avec les résultats majeurs en français

Interkantonales Walddauerbeobachtungsprogramm der Kantone AG, BE, BL, BS, GR, SO, TG, ZH und der Zentralschweizer Umweltämter (LU, NW, OW, SZ, UR, ZG) mit Beteiligung des BAFU 2017-2021

Intercantonal Permanent Forest Observation Program of the Cantons AG, BE, BL, BS, GR, SO, TG, ZG, ZH , of the environmental offices of Central Switzerland (LU, NW, OW, SZ, UR, ZG) and of the Federal Office for the Enviroment (FOEN) German report with main results in English

Programma d’osservazione intercantonale dei boschi nei Cantoni AG, BE, BL, BS,GR, SO, TG, ZH e degli uffici cantonali dell’ambiente della Svizzera centrale (LU,NW, OW, SZ, UR, ZG) con la partecipazione dell‘UFAM Rapporto 6: 2017-2021 Rapporto in tedesco, con introduzione italiana

Long-term investigation of the soil solution in Swiss forests and the influences of air pollutants and climate change on forest health

The TreeNet research and monitoring network has been continuously collecting data from point dendrometers and air and soil microclimate using an automated system since 2011. The goal of TreeNet is to generate high temporal resolution datasets of tree growth and tree water dynamics for research and to provide near real-time indicators of forest grow...

European beech is one of the most important deciduous tree species in natural forest ecosystems in Central Europe. Its dominance is now being questioned by the emerging drought damages due to the increased incidence of severe summer droughts. In Switzerland, Fagus sylvatica have been observed in the Intercantonal Forest Observation Program since 19...

This RMarkdown was created using the R version 4.0.3 (2020-10-10) (R core Team 2021). This scripts includes data preparation and all statistical models including model diagnostics and plots used for the paper. All codes are coded by the main authors, based on literature given in the main paper and supplementary material. In case of any questions pl...

A network of forest monitoring plots was established in Switzerland in 1984, covering gradients in drought, nitrogen deposition, ozone, age, altitude and soil chemistry. Data are available from 95 plots with European beech (Fagus sylvatica) and 76 plots with Norway spruce (Picea abies). The results of this long-term forest monitoring programme show...

The timing of diel stem growth of mature forest trees is still largely unknown, as empirical data with high temporal resolution have not been available so far. Consequently, the effects of day‐night conditions on tree growth remained uncertain. Here we present the first comprehensive field study of hourly‐resolved radial stem growth of seven temper...

Auswirkungen des Trockensommers 2018 auf Flächen der Interkantonalen Walddauerbeobachtung Die Interkantonale Walddauerbeobachtung untersucht seit 1984 die Waldgesundheit an Buchen, Fichten und Eichen in heute 185 Beobachtungsflächen in der Schweiz. Sie ist ein geeignetes Instrument, um schleichende Veränderungen dieser Wälder zu dokumentieren. Aktu...

Soil solution chemistry is influenced by atmospheric deposition of air pollutants, exchange processes with the soil matrix and soil-rhizosphere-plant interactions. In this study we present the results of the long-term Intercantonal Forest Observation Program in Switzerland with soil solution measurements since 1998 on a current total of 47 plots. T...

Excess deposition of the mineral nutrient nitrogen (N) is a serious threat for European forests. Its effect on foliar nutrient concentrations of Fagus sylvatica, along with other predictors, was analyzed in the present study which bases on 30 year's observation data in 74 forest monitoring plots in Switzerland. The data include gradients in soil ch...

In Swiss beech forests (Fagus sylvatica), the increasing frequency of extreme heat and drought events leads to increased tree mortality as well as physiological damage including crown defoliation, discoloration, and dead branches. Interestingly, we find forest stands with damaged or stressed trees next to healthy trees. Therefore, we aim to investi...

The chemistry of the soil solution is influenced by atmospheric deposition of air pollutants, by exchange processes between the soil matrix and the soil solution and by processes between the rhizosphere and the soil. At sites of the Intercantonal Long-term Forest Observation Programme in Switzerland the soil solution has been monitored since 1998 i...

Central Europe experienced an exceptionally hot summer in 2015. The area of investigation in the Central Alps in Switzerland faced the second warmest summer since the beginning of measurements in 1864. As a consequence, agriculture suffered from considerable production losses. But how were forests affected by the hot summer? We analyzed stem growth...

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. W...

[This corrects the article DOI: 10.1371/journal.pone.0205296.].

Studies of stable isotopes of water in the environment have been fundamental to advancing our understanding of how water moves through the soil-plant-atmosphere continuum; however, much of this research focuses on how water isotopes vary in time, rather than in space. We examined the spatial variation in the δ18O and δ2H of throughfall and bulk soi...

Rain recharges soil water storages and either percolates downward into aquifers and streams, or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored....

Studies of stable isotopes of water in the environment have been fundamental to advancing our understanding of how water moves through the soil‐plant‐atmosphere continuum; however, much of this research focuses on how water isotopes vary in time, rather than in space. We examined the spatial variation in the δ18O and δ2H of throughfall and bulk soi...

Atmospheric deposition of nitrogen (N) influences forest demographics and carbon (C) uptake through multiple mechanisms that vary among tree species. Prior studies have estimated the effects of atmospheric N deposition on temperate forests by leveraging forest inventory measurements across regional gradients in deposition. However, in the United St...

Species-level sample characteristics and summarized results. (XLSX)

Full survival equations. (PDF)

Full growth equations. (PDF)

Parameters for each species model. (XLSX)

Species relationships between atmospheric deposition and growth and survival. (PDF)

Atmospheric nitrogen (N) deposition in terrestrial ecosystems is difficult to quantify, especially in forests. In this study, we compared three approaches for determining the wet and dry deposition of nitrogen (total deposition) at 17 intensively monitored forest sites in Switzerland. Specifically, we considered approaches based on: 1) measurements...

Report No. 5 (2013-2017). German report with English introduction

Atmospheric pollution has implications for the health and diversity of temperate forests covering large parts of central Europe. Long-term elevated anthropogenic deposition of nitrogen (N) is driving forest ecosystems from the limitation by N to other nutrients and is found to affect tree health and ectomycorrhizal fungi (EMF), which most trees dep...

Understanding the effects of nitrogen deposition, ozone and climate on tree growth is important for planning sustainable forest management also in the future. The complex interplay of all these factors cannot be covered by experiments. Here we use observational data of mature forests for studying associations of various biotic and abiotic factors w...

Atmospheric pollution has implications for the health and diversity of temperate forests covering large parts of central Europe. Long-term elevated anthropogenic deposition of nitrogen (N) is driving forest ecosystems from the limitation by N to other nutrients and is found to affect tree health and ectomycorrhizal fungi (EMF), which most trees dep...

Stickstoff ist von Natur aus ein Mangelelement in Wäldern und Bäume sind an ein geringes Angebot pflanzenverfügbaren Stickstoffs angepasst. Mit dem Eintrag grosser Mengen leicht verfügbaren Stickstoffs werden die natürlichen Stoffkreisläufe gestört. Die kontinuierliche Stickstoffanreicherung in Wäldern wird auch als «Stickstoffsättigung» bezeichnet...

This fully revised version of Chapter 3 includes updates to the critical levels for ozone agreed at the 30 th ICP Vegetation Task Force Meeting, 14-17 February, 2017, Poznan, Poland. The critical levels for SO2, NOX and NH3 and associated text have not been changed since the previous version.

For human health studies, epidemiology has been established as important tool to examine factors that affect the frequency and distribution of disease, injury, and other health-related events in a defined population, serving the purpose of establishing prevention and control programs. On the other hand, gradient studies have a long tradition in the...

The International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation) was established in 1987. It is led by the UK and has its Programme Coordination Centre at the Centre for Ecology & Hydrology (CEH) in Bangor. It is one of seven ICPs and Task Forces that report to the Working Group on Effects (WGE) o...

Indicators for quantitative assessment of drought risks in beech and Norway spruce forests The application of climate models to forecast future forest development asks for quantitative drought-response relationships, with the term “drought” first needing a definition. The long-term data series of an intercantonal forest observation program allowed...

This chapter presents four geochemical dynamic models (VSD, MAGIC, ForSAFE and SMARTml) that have been used to assess impacts of nitrogen and acidity inputs on soil and soil solution chemistry. These models differ in their complexity and description of some processes. Some models can be used to calculate effects on surface waters as well. For all m...

Empirical critical loads of nitrogen (N) were first presented in a background document for a workshop in 1992 in Sweden. Since their first presentation, the critical loads of N have been updated at regular intervals and for a large number of habitats. This chapter presents a brief history of the empirical critical loads and explains the process of...

To realistically simulate possible future changes in plant species diversity, it is imperative to include the effects of both climate change and atmospheric deposition. Both factors have direct effects on the vegetation, such as the favouring of nitrophilous plants under elevated nitrogen (N) deposition or the elimination of drought-sensitive plant...

Zusammenfassung Aufgrund von langjährigen Waldbeobachtungsdaten aus der Schweiz wurden ver-schiedene Trockenheitsindizes berechnet, verglichen und für eine quantitative Anwendung in Klimaszenarien evaluiert. Der Grundflächenzuwachs konnte am besten mit Indikatoren der Standortswasserbilanz erklärt werden, ebenso die Buchenmortalität, während für di...