Forest Decline and Ozone

1997 ◽  
Keyword(s):  
Forest Decline

scholarly journals Holocene vegetation record of upland northern Calabria, Italy: Environmental change and human impact

The Holocene ◽  
2019 ◽  
Vol 29 (4) ◽  
pp. 633-647 ◽  
Author(s):  
Jan Sevink ◽  
Corrie C Bakels ◽  
Peter AJ Attema ◽  
Mauro A Di Vito ◽  
Ilenia Arienzo
Keyword(s):  
Bronze Age ◽  
Forest Decline ◽  
Human Impacts ◽  
Time Frame ◽  
Archaeological Record ◽  
Pollen Data ◽  
Plant Remains ◽  
Middle Bronze Age ◽  
Climatic Event ◽  
Mobile Pastoralism

Earlier studies on Holocene fills of upland lakes (Lago Forano and Fontana Manca) in northern Calabria, Italy, showed that these hold important palaeoecological archives, which however remained poorly dated. Their time frame is improved by new 14C dates on plant remains from new cores. Existing pollen data are reinterpreted, using this new time frame. Two early forest decline phases are distinguished. The earliest is linked to the 4.2 kyr BP climatic event, when climate became distinctly drier, other than at Lago Trifoglietti on the wetter Tyrrhenian side, where this event is less prominent. The second is attributed to human impacts and is linked to middle-Bronze Age mobile pastoralism. At Fontana Manca (c. 1000 m a.s.l.), it started around 1700 BC, in the higher uplands a few centuries later (Lago Forano, c. 1500 m a.s.l.). In the Fontana Manca fill, a thin tephra layer occurs, which appears to result from the AP2 event (Vesuvius, c. 1700 BC). A third, major degradation phase dates from the Roman period. Land use and its impacts, as inferred from the regional archaeological record for the Raganello catchment, are confronted with the impacts deduced from the palaeoarchives.

scholarly journals Tree Vitality and Forest Health: Can Tree-Ring Stable Isotopes Be Used as Indicators?

2021 ◽  
Author(s):  
Paolo Cherubini ◽  
Giovanna Battipaglia ◽  
John L. Innes
Keyword(s):  
Air Pollution ◽  
Stable Isotopes ◽  
Tree Ring ◽  
Forest Decline ◽  
Forest Health ◽  
Stress Factors ◽  
Tree Vitality ◽  
The Past ◽  
Physiological Processes

Abstract Purpose of Review Society is concerned about the long-term condition of the forests. Although a clear definition of forest health is still missing, to evaluate forest health, monitoring efforts in the past 40 years have concentrated on the assessment of tree vitality, trying to estimate tree photosynthesis rates and productivity. Used in monitoring forest decline in Central Europe since the 1980s, crown foliage transparency has been commonly believed to be the best indicator of tree condition in relation to air pollution, although annual variations appear more closely related to water stress. Although crown transparency is not a good indicator of tree photosynthesis rates, defoliation is still one of the most used indicators of tree vitality. Tree rings have been often used as indicators of past productivity. However, long-term tree growth trends are difficult to interpret because of sampling bias, and ring width patterns do not provide any information about tree physiological processes. Recent Findings In the past two decades, tree-ring stable isotopes have been used not only to reconstruct the impact of past climatic events, such as drought, but also in the study of forest decline induced by air pollution episodes, and other natural disturbances and environmental stress, such as pest outbreaks and wildfires. They have proven to be useful tools for understanding physiological processes and tree response to such stress factors. Summary Tree-ring stable isotopes integrate crown transpiration rates and photosynthesis rates and may enhance our understanding of tree vitality. They are promising indicators of tree vitality. We call for the use of tree-ring stable isotopes in future monitoring programmes.

Influences of forest decline on various properties of soils on Mt. Hirugatake, Tanzawa Mountains, Kanto District, Japan

2003 ◽  
Vol 49 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Kenji Ohse ◽  
Yoriko Ohkawa ◽  
Kenji Tamura ◽  
Teruo Higashi
Keyword(s):  
Forest Decline ◽  
Kanto District ◽  
Tanzawa Mountains

scholarly journals Terpenes and forest decline

Nature ◽  
1991 ◽  
Vol 352 (6337) ◽  
pp. 672-672 ◽  
Author(s):  
HOWARD B. ROSS ◽  
CLAES DE SERVES
Keyword(s):  
Forest Decline

Fertilization as a tool to mitigate forest decline associated with nutrient deficiencies

1987 ◽  
Vol 33 (3-4) ◽  
pp. 265-276 ◽  
Author(s):  
Reinhard F. H�ttl ◽  
Joe Wisniewski
Keyword(s):  
Forest Decline ◽  
Nutrient Deficiencies

Mycorrhizal, association and forest decline (yellowing of spruce)

1990 ◽  
Vol 28 (1-4) ◽  
pp. 381-387 ◽  
Author(s):  
Robert Perrin ◽  
Dominique Estivalet
Keyword(s):  
Forest Decline ◽  
Mycorrhizal Association

scholarly journals Seasonal Drought Induces Hydraulic Dysfunction, Not Carbohydrate Depletion, for Robinia Pseudoacacia in a Semi-humid Forest

2021 ◽  
Author(s):  
Qingyin Zhang ◽  
Xiaoxu Jia ◽  
Mingan Shao
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Forest Decline ◽  
Robinia Pseudoacacia ◽  
Area Index ◽  
Drought Period ◽  
Humid Forest ◽  
Seasonal Drought ◽  
Growing Seasons ◽  
Hydraulic Failure

Abstract BackgroundShifts in rainfall patterns that are associated with climate change are likely to cause widespread forest decline in regions where droughts are predicted to increase in duration and severity. However, causes of forest decline and their physiological mechanisms remain unclear, particularly the roles of carbon metabolism and xylem function. To explore the response of hydraulic architecture and non-structural carbohydrates (NSC) traits under seasonal drought, we conducted a manipulation experiment in a Robinia pseudoacacia plantation in 2015 and 2016 in Loess Plateau of China. Sap-flow, leaf area index, water potential, non-structural carbohydrate concentrations, and hydraulics in different organs were measured. ResultsThe mean pre-dawn and midday leaf water potential after two growing seasons of drought stress was significantly lower (-2.2 MPa and -2.7 MPa, respectively) than those of control trees (-1.5 MPa and -2.0 MPa, respectively). Drought stress accelerated the loss of conductivity, and promoted the formation of narrow hydraulic safety margins, which indicated that hydraulic failure could be a good predictor of “physiological drought” in trees when subjected to two growing seasons of drought. Both sugar and starch concentrations in stems and roots were similar in all trees throughout the drought period, which indicated that trees maintained good coordination between carbon supply and demand when confronted with two growing seasons of drought.ConclusionsOur results emphasized that hydraulic failure plays the predominant role in causing tree death during highly intense drought, while whether "carbon starvation" occurs during tree mortality remains to be tested in longer (multi-year) but less intense drought.

Incipient Forest Decline in the Province of Trento (Northern Italy). Preliminary Sem Observations and Consideration of Inorganic Components of Leaves and Roots

1993 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Marco Ferretti ◽  
Emilia Barbolani ◽  
Paolo Grossoni ◽  
Romano Gellini ◽  
Francesco Pantani
Keyword(s):  
Forest Decline ◽  
Northern Italy ◽  
Leaves And Roots ◽  
Inorganic Components
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