Phenological changes in Europe are still attributable to climate change induced warming

2020 ◽  
Author(s):  
Annette Menzel ◽  
Ye Yuan ◽  
Michael Matiu ◽  
Tim H Sparks ◽  
Helfried Scheifinger ◽  
...  
Keyword(s):  
Climate Change ◽  
Wild Species ◽  
Plant Traits ◽  
Temperature Response ◽  
Early Spring ◽  
Wild Plants ◽  
Phenological Changes ◽  
Species Groups ◽  
Mean Trend ◽  
Ipcc Ar4

<p>During 1971-2000 phenological responses of wild species in spring and summer matched the warming pattern in Europe, whereas timing of farming activities as well as autumnal leaf colouring did not mirror climate change to the same extent (Menzel et al. GCB 2006). These findings were a backbone of the corresponding global attribution study of the IPCC AR4 (Rosenzweig et al. 2007, 2008). Two decades of warming later, however, new phenological findings suggest that especially a lack of chilling and / or increasing influence of photoperiod may have lowered the phenological temperature response and that adaptation in agricultural management is taking place. We therefore updated the GCB 2006 study by asking three questions: What drives the inherent variation of trends? Can we now detect a warming signal in “false” agricultural (i.e. those being directly or indirectly determined by farmers’ management) and autumn phases? Is there still an attributable warming signal in phenology?</p><p>The complete phenological dataset of Germany, Austria and Switzerland (1951-2018, ~97.000 times series, corresponding to 96.3% of PEP725 data) was analysed. We determined linear trends, studied their variation by plant traits / phenogroups, across season and time, and followed IPCC methodology for attributing phenological changes to warming patterns.</p><p>For spring and summer phases of wild plants we found more (significantly) advancing trends (~90% and ~60% sign.) which were stronger in early spring, at higher elevations, but smaller for non-woody insect-pollinated species. Although mean trend strength decreased, changes in spring were strongly attributable to warming in spring and winter. We had similar but less strong findings for agricultural crops in these seasons. In contrast only ~75% of phenological phases set by farmers’ decisions were advancing, however this was the only phenological group for which the mean advance increased, indicating adaptation. Equally trends in farming phases in spring and summer were attributable to warming in winter and summer, respectively. Leaf coloring and fall was now predominantly delayed (57%) which was attributable to winter and spring warming, too.</p><p>Thus, this update of the GCB2006 study demonstrates that there is still a significant and attributable phenological change pattern in Europe, in which number of (significant) trends pointing into the direction of warming increased, but mean trend strength mostly decreased, probably due to a lack of chilling and smaller forcing trends. More attention should be paid to the inherent variability of trends with traits / species groups, season and time triggering divers (e.g. ecological) consequences of these phenological shifts. Still existing differences between the generative period of crops and wild species as well as between the farming season and the general growing season call for more research in this area.</p>

Phenological phases of pollination related to climate change

2021 ◽  
Author(s):  
Samuel Monnier ◽  
Michel Thibaudon ◽  
Jean-Pierre Besancenot ◽  
Charlotte Sindt ◽  
Gilles Oliver
Keyword(s):  
Climate Change ◽  
Pollen Season ◽  
Microscopic Analysis ◽  
Allergic Diseases ◽  
Early Spring ◽  
Late Winter ◽  
General Tendency ◽  
New Production ◽  
Start Date ◽  
Generic Term

<p>Knowledge:</p><p>Rising CO2 levels and climate change may be resulting in some shift in the geographical range of certain plant species, as well as in increased rate of photosynthesis. Many plants respond accordingly with increased growth and reproduction and possibly greater pollen yields, that could affect allergic diseases among other things.</p><p>The aim of this study is the evolution of aerobiological measurements in France for 25-30 years. This allows to follow the main phenological parameters in connection with the pollination and the ensuing allergy risk.</p><p>Material and method:</p><p>The RNSA (French Aerobiology Network) has pollen background-traps located in more than 60 towns throughout France. These traps are volumetric Hirst models making it possible to obtain impacted strips for microscopic analysis by trained operators. The main taxa studied here are birch, grasses and ragweed for a long period of more than 25 years over some cities of France.</p><p>Results:</p><p>Concerning birch but also other catkins or buds’ trees pollinating in late winter or spring, it can be seen an overall advance of the pollen season start date until 2004 and then a progressive delay, the current date being nearly the same as it was 20 years ago, and an increasing trend in the quantities of pollen emitted.</p><p>For grasses and ragweed, we only found a few minor changes in the start date but a longer duration of the pollen season.</p><p>Discussion:</p><p>As regards the trees, the start date of the new production of catkins or buds is never the 1<sup>st</sup> of January but depends on the species. For example, it is early July for birch. For breaking dormancy, flowering, and pollinating, the trees and other perennial species need a period of accumulation of cold degrees (Chilling) and later an accumulation of warm degrees (Forcing). With climate change these periods may be shorter or longer depending of the autumn and winter temperature. Therefore, a change in the annual temperature may have a direct effect on the vegetal physiology and hence on pollen release. It may also explain why the quantities of pollen produced are increasing.</p><p>The Poaceae reserve, from one place to another and without any spatial structuring, very contrasted patterns which make it impossible to identify a general tendency. This is probably due to the great diversity of taxa grouped under the generic term Poaceae, which are clearly not equally sensitive to climate change.</p><p>Conclusion:</p><p>Trees with allergenic pollen blowing late winter or early spring pollinate since 2004 later and produce amounts of pollen constantly increasing. Grasses and ragweed have longer periods of pollination with either slightly higher or most often lower pollen production.</p>

Equilibrium Spin-up of Cold and Warm Permafrost Models

2021 ◽  
Author(s):  
Cameron Ross ◽  
Ryley Beddoe ◽  
Greg Siemens
Keyword(s):  
Climate Change ◽  
Temperature Response ◽  
Ground Temperature ◽  
Future Climate Change ◽  
Climate Projections ◽  
Multiple Model ◽  
Climate Data ◽  
Ground Temperatures ◽  
C Cycle ◽  
Warm Permafrost

<p>Initialization (spin-up) of a numerical ground temperature model is a critical but often neglected step for solving heat transfer problems in permafrost. Improper initialization can lead to significant underlying model drift in subsequent transient simulations, distorting the effects on ground temperature from future climate change or applied infrastructure.  In a typical spin-up simulation, a year or more of climate data are applied at the surface and cycled repeatedly until ground temperatures are declared to be at equilibrium with the imposed boundary conditions, and independent of the starting conditions.</p><p>Spin-up equilibrium is often simply declared after a specified number of spin-up cycles. In few studies, equilibrium is visually confirmed by plotting ground temperatures vs spin-up cycles until temperatures stabilize; or is declared when a certain inter-cycle-temperature-change threshold is met simultaneously at all depths, such as ∆T ≤ 0.01<sup>o</sup>C per cycle. In this study, we investigate the effectiveness of these methods for determining an equilibrium state in a variety of permafrost models, including shallow and deep (10 – 200 m), high and low saturation soils (S = 100 and S = 20), and cold and warm permafrost (MAGT = ~-10 <sup>o</sup>C and >-1 <sup>o</sup>C). The efficacy of equilibrium criteria 0.01<sup>o</sup>C/cycle and 0.0001<sup>o</sup>C/cycle are compared. Both methods are shown to prematurely indicate equilibrium in multiple model scenarios.  Results show that no single criterion can programmatically detect equilibrium in all tested models, and in some scenarios can result in up to 10<sup>o</sup>C temperature error or 80% less permafrost than at true equilibrium.  A combination of equilibrium criteria and visual confirmation plots is recommended for evaluating and declaring equilibrium in a spin-up simulation.</p><p>Long-duration spin-up is particularly important for deep (10+ m) ground models where thermal inertia of underlying permafrost slows the ground temperature response to surface forcing, often requiring hundreds or even thousands of spin-up cycles to establish equilibrium. Subsequent transient analyses also show that use of a properly initialized 100 m permafrost model can reduce the effect of climate change on mean annual ground temperature of cold permafrost by more than 1 <sup>o</sup>C and 3 <sup>o</sup>C under RCP2.6 and RCP8.5 climate projections, respectively, when compared to an identical 25 m model. These results have important implications for scientists, engineers and policy makers that rely on model projections of long-term permafrost conditions.</p>

scholarly journals Wintertime stress, nursing, and lead exposure in Neanderthal children

2018 ◽  
Vol 4 (10) ◽  
pp. eaau9483 ◽  
Author(s):  
Tanya M. Smith ◽  
Christine Austin ◽  
Daniel R. Green ◽  
Renaud Joannes-Boyau ◽  
Shara Bailey ◽  
...  
Keyword(s):  
Climate Change ◽  
Weight Loss ◽  
Human Evolution ◽  
Lead Exposure ◽  
Multidisciplinary Approach ◽  
Modern Human ◽  
Early Spring ◽  
Metal Exposure ◽  
Developmental Stress ◽  
The Relationship

Scholars endeavor to understand the relationship between human evolution and climate change. This is particularly germane for Neanderthals, who survived extreme Eurasian environmental variation and glaciations, mysteriously going extinct during a cool interglacial stage. Here, we integrate weekly records of climate, tooth growth, and metal exposure in two Neanderthals and one modern human from southeastern France. The Neanderthals inhabited cooler and more seasonal periods than the modern human, evincing childhood developmental stress during wintertime. In one instance, this stress may have included skeletal mobilization of elemental stores and weight loss; this individual was born in the spring and appears to have weaned 2.5 years later. Both Neanderthals were exposed to lead at least twice during the deep winter and/or early spring. This multidisciplinary approach elucidates direct relationships between ancient environments and hominin paleobiology.

scholarly journals Land/sea warming ratio in response to climate change: IPCC AR4 model results and comparison with observations

2007 ◽  
Vol 34 (2) ◽  
Author(s):  
Rowan T. Sutton ◽  
Buwen Dong ◽  
Jonathan M. Gregory
Keyword(s):  
Climate Change ◽  
Ipcc Ar4 ◽  
Sea Warming

scholarly journals Seasonal shifts in export of DOC and nutrients from burned and unburned peatland-rich catchments, Northwest Territories, Canada

2018 ◽  
Vol 22 (8) ◽  
pp. 4455-4472 ◽  
Author(s):  
Katheryn Burd ◽  
Suzanne E. Tank ◽  
Nicole Dion ◽  
William L. Quinton ◽  
Christopher Spence ◽  
...  
Keyword(s):  
Climate Change ◽  
Mineral Soil ◽  
Fire Regimes ◽  
Forest Litter ◽  
Early Spring ◽  
Permafrost Region ◽  
Spring Period ◽  
Discontinuous Permafrost ◽  
Run Off ◽  
Spring Freshet

Abstract. Boreal peatlands are major catchment sources of dissolved organic carbon (DOC) and nutrients and thus strongly regulate the landscape carbon balance, aquatic food webs, and downstream water quality. Climate change is likely to influence catchment solute yield directly through climatic controls on run-off generation, but also indirectly through altered disturbance regimes. In this study we monitored water chemistry from early spring until fall at the outlets of a 321 km2 catchment that burned 3 years prior to the study and a 134 km2 undisturbed catchment. Both catchments were located in the discontinuous permafrost zone of boreal western Canada and had  ∼  60 % peatland cover. The two catchments had strong similarities in the timing of DOC and nutrient yields, but a few differences were consistent with anticipated effects of wildfire based on peatland porewater analysis. The 4-week spring period, particularly the rising limb of the spring freshet, was crucial for accurate characterization of the seasonal solute yield from both catchments. The spring period was responsible for  ∼  65 % of the seasonal DOC and nitrogen and for  ∼  85 % of the phosphorous yield. The rising limb of the spring freshet was associated with high phosphorous concentrations and DOC of distinctly high aromaticity and molecular weight. Shifts in stream DOC concentrations and aromaticity outside the early spring period were consistent with shifts in relative streamflow contribution from precipitation-like water in the spring to mineral soil groundwater in the summer, with consistent relative contributions from organic soil porewater. Radiocarbon content (14C) of DOC at the outlets was modern throughout May to September (fraction modern carbon, fM: 0.99–1.05) but likely reflected a mix of aged DOC, e.g. porewater DOC from permafrost (fM: 0.65–0.85) and non-permafrost peatlands (fM: 0.95–1.00), with modern bomb-influenced DOC, e.g. DOC leached from forest litter (fM: 1.05–1.10). The burned catchment had significantly increased total phosphorous (TP) yield and also had greater DOC yield during summer which was characterized by a greater contribution from aged DOC. Overall, however, our results suggest that DOC composition and yield from peatland-rich catchments in the discontinuous permafrost region likely is more sensitive to climate change through impacts on run-off generation rather than through altered fire regimes.

scholarly journals Rapid adaptive evolution to drought in a subset of plant traits in a large-scale climate change experiment

Authorea ◽  
2020 ◽  
Author(s):  
Johannes Metz ◽  
Christian Lampei ◽  
Laura B umler ◽  
Herve Bocherens ◽  
Hannes Dittberner ◽  
...  
Keyword(s):  
Climate Change ◽  
Adaptive Evolution ◽  
Large Scale ◽  
Plant Traits ◽  
Climate Change Experiment

scholarly journals Spring and autumn phenology in sub-mesothermal beech stands from the southwestern extremity of the Carpathians

2020 ◽  
Vol 48 (2) ◽  
pp. 1057-1069
Author(s):  
Radu POPESCU ◽  
Neculae ȘOFLETEA
Keyword(s):  
Climate Change ◽  
Climate Data ◽  
Phenological Data ◽  
The Carpathians ◽  
The North ◽  
Research Areas ◽  
Forest Sites ◽  
Phenological Changes ◽  
Southwestern Area ◽  
The Impact

The research carried out was aimed to assessing the phenological behavior of beech (Fagus sylvatica L.) in the southwestern area of the Carpathians, in submesothermal forest sites, differentiated from the majority mesothermal ones of this species. The data obtained may be used for predicting the phenological changes of the species, especially in the Carpathian area, under the future influence of expected climate change. Assessments for spring and autumn phenology (buds burst -BB and foliation, flowering and leaves senescence) were carried out on a transect with a difference in altitude of 1000 meters, in phenological research areas located at 200 m, 700 m and 1200 m. At each altitude level, 100 trees of I and II Kraft classes were phenologically characterized: 50 trees on the south-facing slope (sunny exposure) and 50 on the north-facing slope (shade exposure).The phenological data were interpreted in relation to climate data recorded in each area by a HOBO U23 Pro v2 sensor. The site conditions of submesothermal climate in the low altitude area led to DOY (day of the year) values below 100. The phenological differentiation of populations is evident in relation with the altitude, while at the same altitudinal level the influence of the exposure was much lower. The gradiental values by altitude sectors highlighted the nonlinearity of the development of foliation phenophase, the value being lower in the first 500 m, where the beech is under the impact of the submesothermal climate. It has been proven both the dependence of the foliation onset depending on the cumulation of temperatures in relation to the DOY moment and also on the values recorded throughout the vegetative rest. The altitudinal gradiental values resulting for flowering in the first and second altitudinal half of transect also differentiate the stands, but are lower than that resulting for BB. The leaves senescence has a delay of 1.8 up to 2.4 days per 100 meters altitude, and the length of the vegetation season is reduced more sharply in the upper half of the analyzed altitudinal transect. The sub-mesothermal climate could be involved in condensation of spring phenophases in the stands of the lower half of the researched area. Our data may be used for predicting the phenological changes, especially in the Carpathian area, under the expected climate change.

scholarly journals Plant hydraulic traits reveal islands as refugia from worsening drought

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Aaron R Ramirez ◽  
Mark E De Guzman ◽  
Todd E Dawson ◽  
David D Ackerly
Keyword(s):  
Climate Change ◽  
Water Relations ◽  
Plant Traits ◽  
Regional Climate ◽  
Channel Islands ◽  
Local Conditions ◽  
Early 21St Century ◽  
Plant Hydraulics ◽  
Drought Conditions ◽  
Potential Climate Change

Abstract Relatively mesic environments within arid regions may be important conservation targets as ‘climate change refugia’ for species persistence in the face of worsening drought conditions. Semi-arid southern California and the relatively mesic environments of California’s Channel Islands provide a model system for examining drought responses of plants in potential climate change refugia. Most methods for detecting refugia are focused on ‘exposure’ of organisms to certain abiotic conditions, which fail to assess how local adaptation or acclimation of plant traits (i.e. ‘sensitivity’) contribute to or offset the benefits of reduced exposure. Here, we use a comparative plant hydraulics approach to characterize the vulnerability of plants to drought, providing a framework for identifying the locations and trait patterns that underlie functioning climate change refugia. Seasonal water relations, xylem hydraulic traits and remotely sensed vegetation indices of matched island and mainland field sites were used to compare the response of native plants from contrasting island and mainland sites to hotter droughts in the early 21st century. Island plants experienced more favorable water relations and resilience to recent drought. However, island plants displayed low plasticity/adaptation of hydraulic traits to local conditions, which indicates that relatively conserved traits of island plants underlie greater hydraulic safety and localized buffering from regional drought conditions. Our results provide an explanation for how California’s Channel Islands function as a regional climate refugia during past and current climate change and demonstrate a physiology-based approach for detecting potential climate change refugia in other systems.

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