scholarly journals Effects of climatic warming on spring phenology in subtropical trees: process-based modelling with experiments designed for model development

2021 ◽  
Author(s):  
Rui Zhang ◽  
Jianhong Lin ◽  
Fucheng Wang ◽  
Heikki Hanninen ◽  
Jiasheng Wu
Keyword(s):  
Model Development ◽  
Climatic Warming ◽  
Spring Phenology ◽  
Tree Phenology ◽  
Adult Trees ◽  
Climatic Scenarios ◽  
Torreya Grandis ◽  
Female Flowering ◽  
First Time ◽  
Temperature Responses

We developed process-based tree phenology models for four subtropical tree species, and for the first time for these trees, we based the model development on explicit experimental work particularly designed to address the processes being modelled. For all the four species, a model of seedling leafout was developed, and for Torreya grandis, a model for female flowering in adult trees was additionally developed. The models generally showed reasonable accuracy when tested against two sources of independent data. In scenario simulations, the models projected an advanced spring phenology under climatic warming for 2020 – 2100. For the leafout of seedlings, the advancing rates varied between 4.7 and 5.9 days per one C warming, with no major differences found between the climatic scenarios RCP4.5 and RCP8.5. For Torreya flowering, less advancing was projected, and the projected advancing per one C warming was less for RCP8.5 (0.9 days / C) than for RCP4.5 (2.3 days / C). The low advancing rates of Torreya flowering were caused by reduced chilling under the warming climate and by the particular temperature responses found for Torreya flowering. These findings highlight the need to base the model development on explicit experiments particularly designed to address the process modelled.

scholarly journals Effects of climatic warming on spring phenology in subtropical trees: process-based modelling with experiments designed for model development

2020 ◽  
Author(s):  
Rui Zhang ◽  
Jianhong Lin ◽  
Fucheng Wang ◽  
Heikki Hänninen ◽  
Jiasheng Wu
Keyword(s):  
Model Development ◽  
Climatic Warming ◽  
Spring Phenology ◽  
Rest Break ◽  
Tree Phenology ◽  
Adult Trees ◽  
Climatic Scenarios ◽  
Torreya Grandis ◽  
Female Flowering ◽  
Biological Realism

AbstractTo project the effects of climatic warming on the timing of spring leafout and flowering in trees, process-based tree phenology models are often used nowadays. Unfortunately, the biological realism of the models is often compromised because the model development has often been based on various assumptions and indirect methods. We developed process-based tree phenology models for four subtropical tree species, and for the first time for these trees, we based the model development on explicit experimental work particularly designed to address the processes being modelled. For all the four species, a model of seedling leafout was developed, and for Torreya grandis, a model for female flowering in adult trees was additionally developed. The models generally showed reasonable accuracy when tested against two sources of independent data: observational phenological records and leafout data from a whole-tree chamber warming experiment. In scenario simulations, the models projected an advanced spring phenology under climatic warming for 2020 – 2100. For the leafout of seedlings, the advancing rates varied between 4.7 and 5.9 days per one °C warming, with no major differences found between the climatic scenarios RCP4.5 and RCP8.5. For Torreya flowering, less advancing was projected, and the projected advancing per one °C warming was less for RCP8.5 (0.9 days / °C) than for RCP4.5 (2.3 days / °C). The low advancing rates of Torreya flowering were caused by reduced chilling under the warming climate and by the particular temperature responses found for Torreya flowering. For instance, our results show that in Torreya flower buds, no rest break (endodormancy release) is seen at +15 °C, whereas in the seedlings of all four species, +15 °C has a clear rest-breaking effect. These findings highlight the need to base the model development on explicit experiments particularly designed to address the process being modelled.

Thermophilous fungi of decomposing sugarcane bagasse

1980 ◽  
Vol 58 (18) ◽  
pp. 2015-2016 ◽  
Author(s):  
D. K. Sandhu ◽  
Surinder Singh ◽  
M. K. Waraich
Keyword(s):  
Aspergillus Fumigatus ◽  
Sugarcane Bagasse ◽  
New Record ◽  
Fungal Species ◽  
Northern India ◽  
First Time ◽  
Temperature Responses

Twenty species of thermophilous fungi were identified from sugarcane bagasse at Batala in Northern India. Seven fungal species are reported from bagasse for the first time and Aspergillus caespitosns is a new record for India. Aspergillus fumigatus was the most common fungus followed by Mncor pusillus. The temperature responses of the fungi revealed 5 microthermophiles, 11 thermotolerant, and 4 true thermophiles. Three species of thermophilous fungi are reported in addition to those already recorded in the literature.

scholarly journals Predicting spring phenology and frost damage risk of Betula spp. under climatic warming: a comparison of two models

2000 ◽  
Vol 20 (17) ◽  
pp. 1175-1182 ◽  
Author(s):  
T. Linkosalo ◽  
T. R. Carter ◽  
R. Hakkinen ◽  
P. Hari
Keyword(s):  
Frost Damage ◽  
Climatic Warming ◽  
Spring Phenology ◽  
Damage Risk

Thermophilous fungi in Port Blair soils

1986 ◽  
Vol 64 (5) ◽  
pp. 1018-1026 ◽  
Author(s):  
S. Singh ◽  
D. K. Sandhu
Keyword(s):  
Dilution Method ◽  
Colony Forming Units ◽  
Thermophilic Species ◽  
Trichoderma Pseudokoningii ◽  
Sporotrichum Thermophile ◽  
Nicobar Islands ◽  
Ecological Importance ◽  
First Time ◽  
Temperature Responses ◽  
Soil Dilution

Soils were collected from eight different sites of saline marshy soils of Port Blair situated in the Andaman and Nicobar islands, India. A total of 93 333 colony-forming units representing 46 species of thermophilous fungi were isolated by the soil dilution method. The fungi were tabulated in order of ecological importance based on their frequency, relative density, and presence in the selected sites of this study. This is apparently the first study of these fungi from the Port Blair soils. Of the 46 species, Mucor miehei, Rhizopus oligosporus, Thermoascus crustaceous, T. thermophilus, and Trichoderma pseudokoningii are new records for India and Acremonium terricola, Aspergillus acculeatus, A. nidulans var. latus, and Sporotrichum thermophile are isolated from Indian soils for the first time. The temperature responses of the fungi revealed 14 microthermophiles and 22 thermotolerant and 10 true thermophilic species. Thirteen species of thermophilous fungi have been reported in addition to those already recorded in the literature.

Model Informed Pediatric Development Applied to Bilastine: Ontogenic PK Model Development, Dose Selection for First Time in Children and PK Study Design

2017 ◽  
Vol 34 (12) ◽  
pp. 2720-2734 ◽  
Author(s):  
Valvanera Vozmediano ◽  
Ander Sologuren ◽  
John C. Lukas ◽  
Nerea Leal ◽  
Mónica Rodriguez
Keyword(s):  
Study Design ◽  
Model Development ◽  
Dose Selection ◽  
Selection For ◽  
First Time

scholarly journals A survey of proximal methods for monitoring leaf phenology in temperate deciduous forests

2020 ◽  
Author(s):  
Kamel Soudani ◽  
Nicolas Delpierre ◽  
Daniel Berveiller ◽  
Gabriel Hmimina ◽  
Jean-Yves Pontailler ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Leaf Senescence ◽  
Vegetation Index ◽  
Broad Band ◽  
Flux Measurement ◽  
Spring Phenology ◽  
Area Index ◽  
Tree Phenology ◽  
Temperate Deciduous ◽  
Energy Exchanges

Abstract. Tree phenology is a major driver of forest-atmosphere mass and energy exchanges. Yet tree phenology has historically not been recorded at flux measurement sites. Here, we used seasonal time-series of ground-based NDVI (Normalized Difference Vegetation Index), RGB camera GCC (Greenness Chromatic Coordinate), broad-band NDVI, LAI (Leaf Area Index), fAPAR (fraction of Absorbed Photosynthetic Active Radiation), CC (Canopy Closure), fRvis (fraction of Reflected Radiation) and GPP (Gross Primary Productivity) to predict six phenological markers detecting the start, middle and end of budburst and of leaf senescence in a temperate deciduous forest. We compared them to observations of budburst and leaf senescence achieved by field phenologists over a 13-year period. GCC, NDVI and CC captured very well the interannual variability of spring phenology (R2 > 0.80) and provided the best estimates of the observed budburst dates, with a mean absolute deviation (MAD) less than 4 days. For the CC and GCC methods, mid-amplitude (50 %) threshold dates during spring phenological transition agreed well with the observed phenological dates. For the NDVI-based method, on average, the mean observed date coincides with the date when NDVI reaches 25 % of its amplitude of annual variation. For the other methods, MAD ranges from 6 to 17 days. GPP provides the most biased estimates. During the leaf senescence stage, NDVI- and CC-derived dates correlated significantly with observed dates (R2 = 0.63 and 0.80 for NDVI and CC, respectively), with MAD less than 7 days. Our results show that proximal sensing methods can be used to derive robust phenological metrics. They can be used to retrieve long-term phenological series at flux measurement sites and help interpret the interannual variability and trends of mass and energy exchanges.

scholarly journals A survey of proximal methods for monitoring leaf phenology in temperate deciduous forests

2020 ◽  
Author(s):  
Kamel Soudani ◽  
Nicolas Delpierre ◽  
Daniel Berveiller ◽  
Gabriel Hmimina ◽  
Jean-Yves Pontailler ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Leaf Senescence ◽  
Flux Measurement ◽  
List Type ◽  
Spring Phenology ◽  
Area Index ◽  
Tree Phenology ◽  
Temperate Deciduous ◽  
Energy Exchanges ◽  
Best Estimates

AbstractTree phenology is a major driver of forest-atmosphere mass and energy exchanges. Yet tree phenology has historically not been recorded at flux measurement sites. Here, we used seasonal time-series of ground-based NDVI (Normalized Difference Vegetation Index), RGB camera GCC (Greenness Chromatic Coordinate), broad-band NDVI, LAI (Leaf Area Index), fAPAR (fraction of Absorbed Photosynthetic Active Radiation), CC (Canopy Closure), fRvis (fraction of Reflected Radiation) and GPP (Gross Primary Productivity) to predict six phenological markers detecting the start, middle and end of budburst and of leaf senescence in a temperate deciduous forest. We compared them to observations of budburst and leaf senescence achieved by field phenologists over a 13-year period. GCC, NDVI and CC captured very well the interannual variability of spring phenology (R2 > 0.80) and provided the best estimates of the observed budburst dates, with a mean absolute deviation (MAD) less than 4 days. For the CC and GCC methods, mid-amplitude (50%) threshold dates during spring phenological transition agreed well with the observed phenological dates. For the NDVI-based method, on average, the mean observed date coincides with the date when NDVI reaches 25% of its amplitude of annual variation. For the other methods, MAD ranges from 6 to 17 days. GPP provides the most biased estimates. During the leaf senescence stage, NDVI- and CC-derived dates correlated significantly with observed dates (R2 =0.63 and 0.80 for NDVI and CC, respectively), with MAD less than 7 days. Our results show that proximal sensing methods can be used to derive robust phenological indexes. They can be used to retrieve long-term phenological series at flux measurement sites and help interpret the interannual variability and decadal trends of mass and energy exchanges.HighlightsWe used 8 indirect methods to predict the timing of phenological events.GCC, NDVI and CC captured very well the interannual variation of spring phenology.GCC, NDVI and CC provided the best estimates of observed budburst dates.NDVI and CC derived-dates correlated with observed leaf senescence dates.

scholarly journals Overestimation of the effect of climatic warming on spring phenology due to misrepresentation of chilling

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Huanjiong Wang ◽  
Chaoyang Wu ◽  
Philippe Ciais ◽  
Josep Peñuelas ◽  
Junhu Dai ◽  
...  
Keyword(s):  
Climate Change ◽  
Freezing Temperature ◽  
Future Climate Change ◽  
Dormancy Release ◽  
Climatic Warming ◽  
Ecosystem Models ◽  
Spring Phenology ◽  
Leaf Unfolding ◽  
Correct Understanding ◽  
Heat Requirement

Abstract Spring warming substantially advances leaf unfolding and flowering time for perennials. Winter warming, however, decreases chilling accumulation (CA), which increases the heat requirement (HR) and acts to delay spring phenology. Whether or not this negative CA-HR relationship is correctly interpreted in ecosystem models remains unknown. Using leaf unfolding and flowering data for 30 perennials in Europe, here we show that more than half (7 of 12) of current chilling models are invalid since they show a positive CA-HR relationship. The possible reason is that they overlook the effect of freezing temperature on dormancy release. Overestimation of the advance in spring phenology by the end of this century by these invalid chilling models could be as large as 7.6 and 20.0 days under RCPs 4.5 and 8.5, respectively. Our results highlight the need for a better representation of chilling for the correct understanding of spring phenological responses to future climate change.

Gall-maker Paradiplosis tumifex (Diptera: Cecidomyiidae) and its inquiline Dasineura balsamicola (Diptera: Cecidomyiidae): an update on epidemic episodes and seasonal ecology in Québec, Canada

2016 ◽  
Vol 148 (4) ◽  
pp. 452-465 ◽  
Author(s):  
Jean-Frédéric Guay ◽  
Diane Bulot ◽  
Jean-Michel Béland ◽  
Conrad Cloutier
Keyword(s):  
Control Strategies ◽  
Gall Midge ◽  
Adult Emergence ◽  
Climatic Conditions ◽  
Eastern Canada ◽  
Spring Phenology ◽  
Seasonal Ecology ◽  
Climatic Scenarios ◽  
Major Pest ◽  
The Impact

AbstractThe balsam gall midge Paradiplosis tumifex Gagné (Diptera: Cecidomyiidae) is a major pest for the Christmas tree industry. This galler is frequently associated with the inquiline Dasineura balsamicola (Lintner) (Diptera: Cecidomyiidae), which is involved in the dynamics of the galler. Despite their importance, seasonal ecology of both midges under the climatic conditions prevailing in eastern Canada is still poorly understood. More importantly, nothing has yet been done to fully assess the impact of temperature on these insects, at key events such as adult emergence and larval overwintering. Here we followed P. tumifex and D. balsamicola spring phenology in the field, as well as their survival during winter diapause under simulated climatic scenarios in the laboratory. We observed spring asynchrony between fir host trees and P. tumifex in the first year of study, but under prevailing epidemic conditions, we observed no impact on summer abundance. We clarified available knowledge on their ecology, showing that overwintering habitats and strategies differ between the galler and its inquiline, which should alter pest control strategies. Experimental overwintering data suggest that diapausing conditions affect these species differentially and could potentially impact the spring sex ratio of their midges, which tends to be strongly female biased.

scholarly journals Warming sensitivity of spring phenology of deciduous species lies in their bud energy budget

2021 ◽  
Author(s):  
Marc Peaucelle ◽  
Josep Penuelas ◽  
Hans Verbeeck
Keyword(s):  
Air Temperature ◽  
Energy Budget ◽  
Deciduous Forests ◽  
Tissue Temperature ◽  
Plant Tissues ◽  
Environmental Constraints ◽  
Climatic Warming ◽  
Deciduous Species ◽  
Spring Phenology

Spring phenology is mainly driven by temperature in extratropical ecosystems. Contrasting responses of foliar phenology to climatic warming, however, have been reported in recent decades, raising important questions about the role of other environmental constraints, especially light. In fact, temperatures differ substantially between plant tissues and the air because plants absorb and lose energy. Yet, phenology studies always substitute plant tissue temperature by air temperature. Here, we explored how solar radiation, wind, and bud traits might affect spring phenology of deciduous forests through the energy budget of buds. We show that air temperature might be an imprecise and biased predictor of bud temperature. Our current interpretation of the plant phenological response to warming should be reconsidered, which will require new observations of bud traits and temperature for accurately quantifying their energy budget.

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