scholarly journals Assessment of long-term vegetation changes on potential isoprenoid emission for a Mediterranean-type ecosystem in France

2000 ◽  
Vol 105 (D23) ◽  
pp. 28863-28873 ◽  
Author(s):  
Gertrud Schaab ◽  
Rainer Steinbrecher ◽  
Bernard Lacaze ◽  
Roman Lenz
Keyword(s):  
Vegetation Changes ◽  
Mediterranean Type Ecosystem ◽  
Isoprenoid Emission

A 1 Ma record of climate-induced vegetation changes using sed aDNA and pollen in a biodiversity hotspot: Lake Towuti, Sulawesi, Indonesia

2021 ◽  
Author(s):  
Akhtar-E Ekram ◽  
Rebecca Hamilton ◽  
Matthew Campbell ◽  
Chloe Plett ◽  
Sureyya Kose ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Carbon Fixation ◽  
Biodiversity Hotspot ◽  
Fossil Pollen ◽  
Vegetation Changes ◽  
Pollen Record ◽  
River Channels ◽  
Sedimentary Record ◽  
Lake Towuti

<p>Several studies have shown that ancient plant-derived DNA can be extracted and sequenced from lake sediments and complement the analysis of fossil pollen in reconstructing past vegetation responses to climate variability and anthropogenic perturbations. The majority of such studies have been performed on Holocene lakes located in cooler higher latitude regions whereas similar studies from tropical lakes are limited. Here, we report a ~1 Ma record of vegetation changes in tropical Lake Towuti (Sulawesi, Indonesia) through parallel pollen and sedimentary ancient DNA (sed aDNA) analysis. Lake Towuti is located in a vegetation biodiversity hotspot and in the centre of the Indo Pacific Warm Pool (IPWP), which comprises the world’s warmest oceanic waters and influences globally important climate systems. In the context of global change, the surface area of the IPWP is rapidly expanding. Lake Towuti is of particular interest since it provides a unique opportunity to obtain a long-term record of IPWP-controlled climate-ecosystem interactions and ecosystem resilience. Stratigraphic analysis of fossil pollen vs. sequencing of preserved chloroplast DNA (cpDNA) signatures (i.e., trnL-P6) both revealed that Lake Towuti experienced significant vegetation changes during the transition from a landscape initially characterized by active river channels, shallow lakes and swamps into a permanent lake ~1 Ma ago. Both proxies marked a predominance of trees or shrubs during most of Lake Towuti’s history, but the trnL-P6 barcoding approach revealed a much higher relative abundance of remote montane conifers, which likely have produced large amounts of chloroplast-rich airborne pollen that were subsequently buried in the sedimentary record. The pollen record showed a higher relative abundance of evergreen tropical forest vegetation, whereas the trnL-P6 record revealed a higher relative abundance of predominantly wetland herbs that must have entered the lake from the local catchment in the form of chloroplast-rich litter. Furthermore, the sedimentary record was rich in presumably wind-derived chloroplast-lacking fern spores, while fern trnL-P6 was only sporadically detected. Only through trnL-P6 barcoding, fern-derived biomass in the sedimentary record could be identified as Schizaeaceae, which is a primitive tropical grass-like fern family often associated with swampy or moist soils. Unlike pollen, trnL-P6 could identify grasses at clade and subfamily levels and confirmed that the majority of grasses in the area represented wet climate C3 grasses or those that can switch between C3 and C4 carbon fixation pathways, whereas grasses that can only perform C4 carbon fixation, indicative of dry climate conditions, were not detected. At least for sediments deposited prior to the Last Glacial Maximum, neither pollen nor trnL-P6 revealed significant vegetation changes between alternating layers of lacustrine green and red sideritic clays thought to have been deposited during orbitally controlled wetter vs. drier periods. These preliminary results suggest that vegetation in this tropical biodiversity hotspot may be relatively resilient to long-term variations in IPWP hydrology.</p>

Historical forest survey data from Eucalyptus - Callitris forests: a valuable resource for long-term vegetation studies

2009 ◽  
Vol 57 (7) ◽  
pp. 541 ◽  
Author(s):  
Robyn K. Whipp ◽  
Ian D. Lunt ◽  
Andrew Deane ◽  
Peter G. Spooner
Keyword(s):  
Survey Data ◽  
Survey Methods ◽  
Quantitative Information ◽  
Data Sources ◽  
Stem Density ◽  
Vegetation Changes ◽  
Management Interventions ◽  
Eastern Australia ◽  
Historical Forest

Quantitative information about historical changes in natural ecosystems is important for guiding management interventions. However, few accurate data sources are available for documenting long-term vegetation changes. In this paper, we describe a neglected source of quantitative information on historical forest structure: forest inventory strip surveys, which were widely used in eastern Australia from 1915 to the 1940s. Strip surveys provide quantitative information on the species composition, stem density, basal area, stem form and size class distributions of dominant tree species. Such information is not available from other widespread data sources. Strip surveys usually surveyed 10% of the total forest area. In this paper, we describe the original survey methods, demonstrate how to decode data-book entries, and analyse a sample dataset from the Pilliga State Forests in northern New South Wales to illustrate the information that can be obtained from this material. Strip survey data-books are poorly archived. Many books exist for Eucalyptus–Callitris forests in northern and central NSW, and additional books may exist for many other forest types in eastern Australia. Strip surveys provide a valuable data source for studying long-term vegetation changes in forest ecosystems. We urge forest managers to search for and preserve this precious archival material.

Plant hydraulic responses to long-term dry season nitrogen deposition alter drought tolerance in a Mediterranean-type ecosystem

Oecologia ◽  
2016 ◽  
Vol 181 (3) ◽  
pp. 721-731 ◽  
Author(s):  
Alexandria L. Pivovaroff ◽  
Louis S. Santiago ◽  
George L. Vourlitis ◽  
David A. Grantz ◽  
Michael F. Allen
Keyword(s):  
Drought Tolerance ◽  
Nitrogen Deposition ◽  
Dry Season ◽  
Mediterranean Type Ecosystem

scholarly journals Conserving the endemic birds on the Comoro Islands, II: population fluctuations on Ngazidja

1992 ◽  
Vol 2 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Jan Stevens ◽  
Marc Herremans ◽  
Michel Louette
Keyword(s):  
Vegetation Changes ◽  
Population Fluctuations ◽  
Population Changes ◽  
Point Counts ◽  
Shrub Layer ◽  
Forest Exploitation ◽  
Endemic Birds ◽  
Land Bird ◽  
Comoro Islands

SummaryLand bird abundances on Ngazidja, Comoro Islands, obtained by point counts in September 1985 and November–December 1989 are compared. The overall abundance of most species did not differ significantly. Most differences can be interpreted as normal within-year fluctuations. Some important changes are identified and attributed to shortterm vegetation changes: increase of Columba polleni, Coracopsis vasa, Zoonavena grandidieri, Coracina cinerea in Nioumbadjou after abandonment of forest exploitation; decrease of Coracina cinerea at M'Lima Mani North after replacement of the natural shrub layer by bananas. Genuine long-term population changes occur in Coracopsis nigra (increase) and Corvus albus (decrease).

Long-term vegetation changes in the four mega-sandy lands in Inner Mongolia, China

2015 ◽  
Vol 30 (9) ◽  
pp. 1613-1626 ◽  
Author(s):  
Daojing Zhou ◽  
Xia Zhao ◽  
Huifeng Hu ◽  
Haihua Shen ◽  
Jingyun Fang
Keyword(s):  
Inner Mongolia ◽  
Vegetation Changes

scholarly journals Condicionantes de la respuesta vegetal al cambio climático. Una perspectiva paleobiolágica.

2001 ◽  
Vol 26 ◽  
pp. 157-176 ◽  
Author(s):  
José S. Carrión
Keyword(s):  
Climatic Change ◽  
Plant Communities ◽  
Fire Regime ◽  
Climatic Factors ◽  
Vegetation Changes ◽  
Great Resistance ◽  
Quaternary Climate ◽  
Decadal Scale ◽  
Los Grupos

RESUMEN. Condicionantes de la respuesta vegetal al cambio climático. Una perspectiva paleobiolágica. Este artículo proporciona una revisión de las pautas y procesos de cambio vegetal en relación con el cambio climático, así como sobre la cuestión del equilibrio clima-vegetación y sus condicionantes, desde una perspectiva paleobiológica basada fundamentalmente en secuencias polínicas. En la escala evolutiva, la mayor parte de los eventos de migración, extinción de especies y reorganización de la estructura ecológica se describen adecuadamente como respuestas tipo umbral bióticamente condicionadas. Se constata una gran resistencia a la invasión de las comunidades establecidas, siendo de mayor relevancia la historia biológica de los grupos que el propio sentido del cambio climático en orden a establecer los grupos dominantes después de cada crisis. El nexo entre la biología evolutiva y la biogeografía lo proporcionan los estudios paleoecológicos a escala orbital. Durante los ciclos climáticos del Cuaternario, hubo dispersión de poblaciones, extinciones locales y desagregación de comunidades. A esta escala, el clima ejerce un control a largo plazo sobre el cortejo florístico disponible, dentro de las limitaciones que impone la historia evolutiva regional. Hay que destacar el carácter no lineal de las respuestas de la vegetación en cada una de las tres frecuencias de control astronómico. Ante los cambios climáticos acaecidos desde la última glaciación, la vegetación ibérica se ha mostrado a menudo inerte durante milenios y a veces reactiva en la escala de centurias o incluso décadas. Las respuestas abruptas pueden condicionarse a factores no climáticos, muy a menudo cambios en el regimen de fuegos. La cuestión del equilibrio es, simplemente, un problema de escala. En este sentido, el control del cambio vegetal se deslizaría sutilmente desde lo climático a lo biótico conforme disminuimos la escala temporal y/o espacial. A la hora de interpretar los cambios en la composición, estructura y distribución de comunidades vegetales, las oscilaciones climáticas abruptas representan accidentes históricos que, eventualmente, pueden llegar a ser más relevantes que las tendencias climáticas a largo plazo.Palabras clave. Paleoecología, palinología, hiogeografía histórica, vegetación, cambio climático, EspañaABSTRACT. Vegetation response to climatic change. A palaeobiological perspective. This paper reviews the patterns and processes of vegetation change in response to climatic factors, and the question of climate- vegetation equilibrium from a palacoecological perspective. At an evolutionary temporal scale, processes such as migration, species extincion, and reorganization of the ecological structure are adequately described by biotically-conditioned threshold responses. Established communities exhibit great resistance to invasion, being pre-adaptive traits of higher importance than the direction of climate change in determining the dominant group after each environmental crisis. Palaeoecological studies at the orbital scale provide a link between evolutionary and ecological processes. The Quaternary climate variation induced dispersion of plant populations, local extinctions and disaggregation of plant communities. Climate exerted control on long-term species pool within the constraints imposed by regional evolutionary history. Vegetation responses to astronomic forces were characteristically non linear. Iberian plant communities have often behaved inertial to climate changes occurring since the last glacial maximum. Sometimes, however, they have been very sensitive, providing century- to decadal-scale responses. Abrupt vegetation changes may be related with non-climatic factors, principally changes in the fire regime. The question of climate-vegetation equilibrium is a scale problem, where the control of vegetation changes would shift from climatic to biotic controls as the temporal and spatial scales are shortened. While interpreting compositional, structural and distributional changes in plant communities, abrupt climatic changes may represent historical accidents eventually more relevant than long-term climatic trends.Key words. Palaeoecology, palynology, historical biogeography, vegetation, climatic change, Spain

scholarly journals Long-term vegetation changes of treeless heath communities in northern Fennoscandia: Links to climate change trends and reindeer grazing

2018 ◽  
Vol 29 (3) ◽  
pp. 469-479 ◽  
Author(s):  
Tuija Maliniemi ◽  
Jutta Kapfer ◽  
Patrick Saccone ◽  
Anu Skog ◽  
Risto Virtanen
Keyword(s):  
Climate Change ◽  
Vegetation Changes ◽  
Northern Fennoscandia ◽  
Heath Communities
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