Tree-ring record in Ethiopian church forests reveals successive generation differences in growth rates and disturbance events

Abstract. Wetland forests around the world have been reduced to a small proportion of their original expanse due to changing climatic conditions and intensification of human land use activities. As a case in point, the Columbia bottomland hardwood forests along the Brazos-Colorado Coastal Basin on the Gulf coast of Texas are currently threatened by an increasingly erratic hydroclimate in the form of both extreme floods as well as droughts, and by urban expansion. In this study, we use dendrochronology and tree-ring carbon isotopes to understand the effect of changing hydroclimatic conditions on the functional attributes of these forests. We examined tree-rings of Quercus nigra at four sites within the Columbia bottomlands, of which one site experiences frequent and prolonged flooding, while the other three are less flood-prone. The objectives of this study were to: (i) understand the impact of hydroclimatic variation on growth rates using tree-ring width analysis, (ii) assess the magnitude of physiological stress inflicted by extreme hydroclimatic conditions using tree-ring δ13C measurements, and (iii) evaluate the relationship between physiological stress and growth inhibition. Growth rates across the landscape were influenced most strongly by mid-growing season climate, while early-growing season climate inflicted the greatest physiological stress. Neither growth inhibition nor changes in δ13C values were observed in trees at the wetter site under extreme hydrologic conditions such as droughts or floods. In addition, trees at the wet site were less sensitive to precipitation and showed no response to higher temperatures. In contrast, trees of the three drier sites experienced growth inhibition and had higher tree-ring δ13C values during dry periods. Our results indicate higher physiological resilience in trees growing under wetter conditions. Management and conservation strategies dependent on site-specific conditions are critical for the health of these wetland forests under a rapidly changing hydroclimate. This study provides the first dendrochronological baseline for this region and thresholds of optimum conditions for the growth and health of these forests which can assist management decisions such as streamflow regulation and conservation plans.

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Lichenometric dating using Rhizocarpon subgenus Rhizocarpon in the Patagonian Andes, Argentina

Quaternary Research ◽

10.1016/j.yqres.2009.01.012 ◽

2009 ◽

Vol 71 (3) ◽

pp. 271-283 ◽

Cited By ~ 12

Author(s):

Irene Adriana Garibotti ◽

Ricardo Villalba

Keyword(s):

Tree Ring ◽

Growth Rates ◽

Growth Curves ◽

The Past ◽

Glacier Fluctuations ◽

Andean Cordillera ◽

Latitudinal Difference ◽

Patagonian Andes ◽

Over Time ◽

Lichen Growth

AbstractThis study represents the first attempt to develop and apply lichenometric dating curves of Rhizocarpon subgenus Rhizocarpon for dating glacier fluctuations in the Patagonian Andes. Six glaciers were studied along the Patagonian Andes. Surfaces of known ages (historical evidences and tree-ring analyses) were used as control sites to develop indirect lichenometric dating curves. Dating curves developed for the studied glaciers show the same general logarithmic form, indicating that growth rate of subgenus Rhizocarpon decreases over time. The strong west–east precipitation gradient across the Andean Cordillera introduces statistically significant differences in the growth curves, with faster growth rates in the moist west sites than the drier eastern sites. Latitudinal difference among the studied glaciers does not appear to be a major factor regulating lichen growth rates. Therefore, we developed two lichenometric curves for dating glacier fluctuations in wetter and drier sites in the Patagonian Andes during the past 450 yrs. Application of the developed curves to moraine dating allowed us to complement glacial chronologies previously obtained by tree-ring analyses. A first chronosequence for moraine formation in the Torrecillas Glacier (42°S) is presented. Our findings confirm the utility of lichenometry to date deglaciated surfaces in the Patagonian Andes.

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Global tree-ring analysis reveals rapid decrease in tropical tree longevity with temperature

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2003873117 ◽

2020 ◽

Vol 117 (52) ◽

pp. 33358-33364 ◽

Cited By ~ 1

Author(s):

Giuliano Maselli Locosselli ◽

Roel J. W. Brienen ◽

Melina de Souza Leite ◽

Manuel Gloor ◽

Stefan Krottenthaler ◽

...

Keyword(s):

Tree Ring ◽

Growth Rates ◽

Tree Mortality ◽

Forest Biomass ◽

Global Scale ◽

Forest Composition ◽

Future Evolution ◽

Tree Ring Data ◽

The Tropics ◽

Tropical Lowlands

Forests are the largest terrestrial biomass pool, with over half of this biomass stored in the highly productive tropical lowland forests. The future evolution of forest biomass depends critically on the response of tree longevity and growth rates to future climate. We present an analysis of the variation in tree longevity and growth rate using tree-ring data of 3,343 populations and 438 tree species and assess how climate controls growth and tree longevity across world biomes. Tropical trees grow, on average, two times faster compared to trees from temperate and boreal biomes and live significantly shorter, on average (186 ± 138 y compared to 322 ± 201 y outside the tropics). At the global scale, growth rates and longevity covary strongly with temperature. Within the warm tropical lowlands, where broadleaf species dominate the vegetation, we find consistent decreases in tree longevity with increasing aridity, as well as a pronounced reduction in longevity above mean annual temperatures of 25.4 °C. These independent effects of temperature and water availability on tree longevity in the tropics are consistent with theoretical predictions of increases in evaporative demands at the leaf level under a warmer and drier climate and could explain observed increases in tree mortality in tropical forests, including the Amazon, and shifts in forest composition in western Africa. Our results suggest that conditions supporting only lower tree longevity in the tropical lowlands are likely to expand under future drier and especially warmer climates.

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Ontogenetic Basis of Among-Generation Differences in Size-Related Traits in a Polyphenic Butterfly

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.612330 ◽

2021 ◽

Vol 9 ◽

Author(s):

Toomas Esperk ◽

Toomas Tammaru

Keyword(s):

Growth Rates ◽

Direct Development ◽

Developmental Pathways ◽

General Context ◽

Adaptive Responses ◽

Size Growth ◽

Different Temperatures ◽

Generation Differences ◽

The Difference ◽

Varying Environments

Seasonal polyphenisms are cases in which individuals representing generations occurring in different times of the year systematically differ in their morphological, physiological, and/or behavioral traits. Such differences are often assumed to constitute adaptive responses to seasonally varying environments, but the evidence for this is still scarce. The adaptive character of the response would be corroborated by the pattern in which the decision about choosing a particular seasonal phenotype is made before the onset of respective environmental conditions (anticipatory plasticity). Alternatively, the between-generation differences can be caused by immediate effects of seasonally varying environments (responsive plasticity). Here we reared the larvae of the seasonally polymorphic map butterfly Araschnia levana under two different photoperiodic regimes, which provided different seasonal cues. These two treatments induced direct development and diapause pathways, respectively. Replicating the experiment at different temperatures and levels of host plant quality allowed us to evaluate both the anticipatory and the responsive components of the associated plastic changes in life-history traits. Larvae representing the direct development pathway invariably had higher growth rates and shorter development periods, although the difference between the developmental pathways was smaller at inferior host quality. Body size differences between the developmental pathways turned out to be less consistent, as the natural pattern of higher pupal mass of the directly developing individuals could only be reproduced at lower rearing temperature. Though being considerably modified by immediate environmental effects, the between-generation differences in size, growth rates, and larval are largely based on anticipatory plasticity (= responses to photoperiodic cues) and should be treated as seasonal adaptations in A. levana. In a more general context, we show how investigating the proximate basis of size differences can serve the purpose of identifying the limits of phenotypic plasticity in juvenile growth schedules.

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Shellfish could supplant tree-ring climate data

Nature ◽

10.1038/news.2010.110 ◽

2010 ◽

Author(s):

Richard A. Lovett

Keyword(s):

Tree Ring ◽

Climate Data

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Reduced growth rates of hair in mice following radiation

Archives of Dermatology ◽

10.1001/archderm.94.4.491 ◽

1966 ◽

Vol 94 (4) ◽

pp. 491-498 ◽

Cited By ~ 3

Author(s):

F. D. Malkinson

Keyword(s):

Growth Rates

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Institutional Theory of Endless Redistribution

Voprosy Ekonomiki ◽

10.32609/0042-8736-2005-7-4-18 ◽

2005 ◽

pp. 4-18 ◽

Cited By ~ 5

Author(s):

K. Sonin

Keyword(s):

Property Rights ◽

Institutional Theory ◽

Growth Rates ◽

Rent Seeking ◽

Economic Institutions ◽

Wide Spread ◽

Grass Roots ◽

Protection Systems ◽

Private Protection ◽

The Rich

In unequal societies, the rich may benefit from shaping economic institutions in their favor. This paper analyzes the dynamics of institutional subversion by focusing on public protection of property rights. If this institution functions imperfectly, agents have incentives to invest in private protection of property rights. The ability to maintain private protection systems makes the rich natural opponents of public protection of property rights and precludes grass-roots demand to drive the development of the market-friendly institution. The economy becomes stuck in a bad equilibrium with low growth rates, high inequality of income, and wide-spread rent-seeking. The Russian oligarchs of the 1990s, who controlled large stakes of newly privatized property, provide motivation for this paper.

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Waiting for a New Model of Growth: Russia’s Social and Economic Development in 2013

Voprosy Ekonomiki ◽

10.32609/0042-8736-2014-2-4-32 ◽

2014 ◽

pp. 4-32 ◽

Cited By ~ 7

Author(s):

V. Mau

Keyword(s):

Economic Policy ◽

Economic Development ◽

Economic Performance ◽

Growth Rates ◽

Global Crisis ◽

New Model ◽

Social And Economic Development ◽

Economic Risks

The paper deals with Russian social and economic development in 2013 and prospects for the next year or two. The author discusses the logic and trends of the global crisis started in 2008. This is the basis for further analysis of current Russian economic performance with special emphasis on the problem of growth rates deceleration. Special attention is paid to economic risks and priorities of economic policy.

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Impacts of Paris Agreement on Russian economy

Voprosy Ekonomiki ◽

10.32609/0042-8736-2018-4-76-94 ◽

2018 ◽

pp. 76-94 ◽

Cited By ~ 1

Author(s):

I. A. Makarov ◽

C. Henry ◽

V. P. Sergey

Keyword(s):

Climate Change ◽

Economic Policy ◽

Growth Rates ◽

Paris Agreement ◽

Gdp Growth ◽

Russian Economy ◽

Climate Policies

The paper applies multiregional CGE Economic Policy Projection and Analysis (EPPA) model to analyze major risks the Paris Agreement on climate change adopted in 2015 brings to Russia. The authors come to the conclusion that if parties of the Agreement meet their targets that were set for 2030 it may lead to the decrease of average annual GDP growth rates by 0.2-0.3 p. p. Stricter climate policies beyond this year would bring GDP growth rates reduction in2035-2050 by additional 0.5 p. p. If Russia doesn’t ratify Paris Agreement, these losses may increase. In order to mitigate these risks, diversification of Russian economy is required.

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