Developmental versus environmental control of early leaf phenology in juvenile Ohio buckeye (Aesculus glabra)

2004 ◽  
Vol 82 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Carol K Augspurger
Keyword(s):  
Leaf Senescence ◽  
Environmental Control ◽  
Vertical Gradient ◽  
Leaf Expansion ◽  
Forest Understory ◽  
Bud Break ◽  
Spring Phenology ◽  
Canopy Trees ◽  
Leaf Drop ◽  
Aesculus Glabra

The spring phenology of juveniles of many canopy tree species in deciduous forests predates that of adult conspecifics. To determine whether the earlier phenology of seedlings of Aesculus glabra Willd. (Ohio buckeye) in Illinois, U.S.A., is developmentally or environmentally controlled, seedlings of five maternal parents were grown either in the understory or above a barn roof, simulating environmental conditions experienced at canopy height. Relative to canopy seedlings, understory seedlings had significantly earlier bud break (mean = 6 d), leaf expansion (8 d), leaf senescence (23 d), and leaf drop (18 d). Bud break and leaf expansion of canopy seedlings equalled that of canopy trees of Ohio buckeye, but senescence and leaf drop of canopy seedlings predated canopy trees by 45 and 67 d, respectively. Overall, results show evidence for environmental control over the spring phenology of juveniles. Thermal sums in spring accumulated more rapidly in the forest understory where nighttime temperatures were warmer than above the barn roof. Thus, the environmental control of spring phenology appears to be a non-stage-specific temperature cue that accumulates at different rates along the forest's vertical gradient. In contrast, senescence and leaf drop, while somewhat responsive to the environment, displayed strong developmental constraint.Key words: bud break, developmental constraint, leaf drop, leaf expansion, leaf senescence, thermal sums.

scholarly journals Assessment of Erysiphe necator Ascospore Release Models for Use in the Mediterranean Climate of Western Oregon

Plant Disease ◽  
2018 ◽  
Vol 102 (8) ◽  
pp. 1500-1508 ◽  
Author(s):  
L. D. Thiessen ◽  
T. M. Neill ◽  
W. F. Mahaffee
Keyword(s):  
Environmental Conditions ◽  
Predictive Models ◽  
Climatic Conditions ◽  
Rain Event ◽  
Bud Break ◽  
Erysiphe Necator ◽  
Climatic Regions ◽  
Airborne Inoculum ◽  
Leaf Drop ◽  
Ascospore Release

Predictive models have been developed in several major grape-growing regions to correlate environmental conditions to Erysiphe necator ascospore release; however, these models may not be broadly applicable in regions with different climatic conditions. To assess ascospore release in near-coastal regions of western Oregon, chasmothecia (syn. cleistothecia) were collected prior to leaf drop and placed onto natural and artificial grape trunk segments and overwintered outside. Ascospore release was monitored for three overwintering seasons using custom impaction spore traps from leaf drop (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie [BBCH] 97) until the onset of the disease epidemic in the following growing season. Airborne inoculum was concurrently monitored in a naturally infested research vineyard. Weather and ascospore release data were used to assess previously developed models and correlate environmental conditions to ascospore release. Ascospore release was predicted by all models prior to bud break (BBCH 08), and was observed from the first rain event following the start of inoculum monitoring until monitoring ceased. Previously developed models overpredicted ascospore release in the Willamette Valley and predicted exhaustion of inoculum prior to bud break. The magnitude of ascospore release could not be correlated to environmental conditions; thus, a binary ascospore release model was developed where release is a function of the collective occurrence of the following factors within a 24-h period: >6 h of cumulative leaf wetness during temperatures >4°C, precipitation >2.5 mm, and relative humidity >80%. The Oregon model was validated using field-collected ascospore datasets, and predicted ascospore release with 66% accuracy (P = 0.02). Extant methods for estimating ascospore release may not be sufficiently accurate to use as predictive models in wet, temperate climatic regions.

Patterns of leaf phenology in forest understory

1994 ◽  
Vol 72 (4) ◽  
pp. 409-414 ◽  
Author(s):  
Shigeru Uemura
Keyword(s):  
Snow Cover ◽  
Shade Tolerance ◽  
Growth Form ◽  
Light Regime ◽  
Forest Understory ◽  
Leaf Habit ◽  
Canopy Trees ◽  
High Insulation ◽  
Rapid Emergence ◽  
Foliar Phenology

Foliar phenologies of forest understory plants were categorized, and the distribution pattern of leaf habit was examined among different forest environments. Various patterns of foliar phenology were found, especially in herbaceous plants. In addition to the seasonal light regime controlled by the phenology of canopy trees, differences in the length of period with snow cover led to the divergence. Perennial-leaved plants predominate in intensely shaded habitats while annual-leaved plants are more abundant in less shaded habitats. The shade tolerance of perenniel-leaved plants can be considered a preadaptation to snow tolerance. In contrast with the perennial-leaved plants, biennial-leaved plants with leaves overwintering 1 year appear to be favored in euphotic habitats with high insulation both in spring and in autumn. These species are effective competitors in spring because of rapid emergence of current leaves, probably through retranslocation of resources accumulated in the previous year. Another adaptive trait is found in heteroptic plants simultaneously having summer-green leaves and overwintering leaves; these types of leaves seem to function in predictable and quite different environments in a year. Key words: foliar phenology, growth form, light resource, overwintering leaf, snow cover.

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.

Atmospheric Warming-Associated Phenological Earliness Does Not Increase the Length of Growing Season in Himalayan Trees

2021 ◽  
Author(s):  
G C S Negi ◽  
Pradeep Singh ◽  
S P Singh
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Ecosystem Services ◽  
Atmospheric Temperature ◽  
Himalayan Region ◽  
Ecosystem Structure ◽  
Bud Break ◽  
Impact Of Climate Change ◽  
Leaf Drop ◽  
The Impact

Abstract We present phenological data for two time periods (1985–1987 and 2014–2016) on major tree species (Shorea robusta, Pinus roxburghii, Myrica esculenta, Quercus leucotrichophora, Rhododendron arboreum, Quercus floribunda, and Machilus duthiei) occurring along an altitudinal gradient of 300–2,200 m asl of Himalayan forests (a data-deficient region identified by the IPCC, 2007), and show that bud break and leafing in trees has advanced at 0.20 days/year, which is associated with a significant (P < 0.001) increase in atmospheric temperature (0.038°C/year) over the years in the study area. Also, the leaf drop period has advanced correspondingly (0.40 days/year); hence, the length of season (LOS) did not increase in these trees. This finding is contrary to the report of increase in LOS due to climatic warming from temperate latitudes of the world and satellite-based studies in Himalayan region. Arguably, phenomena such as bud break and leafing may not be captured by remote sensing, which is critical for determining the impact of climate change on the forest vegetation of the eco-sensitive Himalayan region. We suggest that this phenological earliness may alter forest structure and functioning and associated ecosystem services of these forests in the long run. Study Implications: This study suggests that bud break and leafing in trees has advanced, an advancement that is associated with the significant increase in atmospheric temperature over the years in the study area. However, the leaf drop period has advanced correspondingly; hence, the length of season of trees in the study area did not increase. Nonetheless, the earliness in the leafing and leaf drop have potential implications on forest ecosystem structure and functioning, such as photosynthesis, carbon assimilation, increased asynchrony in plant-pollinators and animal interactions, reproduction success, and herbivory that require further detailed investigation. Warming may also advance seed maturation and desiccation of seeds that may disrupt the synchrony between monsoon and tree seed germination, forest regeneration, and ensuing ecosystem services. Generalizations on a regional scale on the impact of climate change on annual patterns of growth of forests that are based on remote-sensing studies could mask the impact of the premonsoon period, when bud break and leafing take place. These impacts may not be captured by remote sensing; impacts which, in this study, we have found to be critical.

scholarly journals Root and Shoot Growth Response of Balled-and-Burlapped and Pot-in-Pot Sugar Maple to Transplanting at Five Phenological Growth Stages

2008 ◽  
Vol 26 (3) ◽  
pp. 171-176
Author(s):  
Lisa E. Richardson-Calfee ◽  
J. Roger Harris ◽  
Jody K. Fanelli
Keyword(s):  
Root Length ◽  
Sugar Maple ◽  
Growth Stages ◽  
Bud Break ◽  
Phenological Stage ◽  
Phenological Stages ◽  
Trunk Diameter ◽  
Bud Set ◽  
Leaf Drop ◽  
B Trees

Abstract The combined effects of phenological growth stage of a tree (e.g., bud break or bud set) and production method on plant response to transplanting are not well documented. This experiment therefore examined shoot extension, trunk diameter increase, and new root length production in balled-and-burlapped (B&B) and pot-in-pot (PIP) sugar maples (Acer saccharum Marsh.) transplanted at five different phenological stages between fall 2000 and early summer 2001 (leaf drop, root quiescence, root activation, bud break, or bud set). Growth measurements were made at bud set and root quiescence in 2001 at bud set in 2002. For B&B trees, total new root length on rhizotron windows was generally greatest for trees planted at bud break and lowest for trees planted at leaf drop. Trees transplanted at leaf drop or root quiescence had the greatest trunk diameter increase, and there was no strong effect of phenological stage at planting on shoot extension. For PIP trees, evidence was weak for a phenological stage effect on post-transplant root length production and trunk diameter increase. Trees transplanted at leaf drop or bud break had the greatest shoot extension. Overall, under the well-irrigated conditions of this study, planting at bud break resulted in the most favorable transplant response for B&B trees, and PIP trees appeared to transplant with equal success at all phenological stages, including after bud set in July.

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

2021 ◽  
Vol 18 (11) ◽  
pp. 3391-3408
Author(s):  
Kamel Soudani ◽  
Nicolas Delpierre ◽  
Daniel Berveiller ◽  
Gabriel Hmimina ◽  
Jean-Yves Pontailler ◽  
...  
Keyword(s):  
Time Series ◽  
Interannual Variability ◽  
Leaf Senescence ◽  
Vegetation Index ◽  
Sigmoid Function ◽  
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 rarely been monitored in a consistent way throughout the life of a flux-tower site. Here, we used seasonal time series of ground-based NDVI (Normalized Difference Vegetation Index), RGB camera GCC (greenness chromatic coordinate), broadband 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 using an asymmetric double sigmoid function (ADS) fitted to the time series. We compared them to observations of budburst and leaf senescence achieved by field phenologists over a 13-year period. GCC, NDVI and CC captured the interannual variability of spring phenology very well (R2>0.80) and provided the best estimates of the observed budburst dates, with a mean absolute deviation (MAD) of less than 4 d. 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 d. The ADS method used to derive the phenological markers provides the most biased estimates for the GPP and GCC. 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 an MAD of less than 7 d. 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 eddy covariance (EC) flux measurement sites and help interpret the interannual variability and trends of mass and energy exchanges.

scholarly journals Effects of the Simulated Enhancement of Precipitation on the Phenology of Nitraria tangutorum under Extremely Dry and Wet Years

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1474
Author(s):  
Fang Bao ◽  
Zhiming Xin ◽  
Jiazhu Li ◽  
Minghu Liu ◽  
Yanli Cao ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Plant Phenology ◽  
Regulation Mechanism ◽  
Arid Areas ◽  
Leaf Fall ◽  
Spring Phenology ◽  
Leaf Unfolding ◽  
Simulated Precipitation ◽  
Leaf Budding ◽  
End Times

Plant phenology is the most sensitive biological indicator that responds to climate change. Many climate models predict that extreme precipitation events will occur frequently in the arid areas of northwest China in the future, with an increase in the quantity and unpredictability of rain. Future changes in precipitation will inevitably have a profound impact on plant phenology in arid areas. A recent study has shown that after the simulated enhancement of precipitation, the end time of the leaf unfolding period of Nitraria tangutorum advanced, and the end time of leaf senescence was delayed. Under extreme climatic conditions, such as extremely dry or wet years, it is unclear whether the influence of the simulated enhancement of precipitation on the phenology of N. tangutorum remains stable. To solve this problem, this study systematically analyzed the effects of the simulated enhancement of precipitation on the start, end and duration of four phenological events of N. tangutorum, including leaf budding, leaf unfolding, leaf senescence and leaf fall under extremely dry and wet conditions. The aim of this study was to clarify the similarities and differences of the effects of the simulated enhancement of precipitation on the start, end and duration of each phenological period of N. tangutorum in an extremely dry and an extremely wet year to reveal the regulatory effect of extremely dry and excessive amounts of precipitation on the phenology of N. tangutorum. (1) After the simulated enhancement of precipitation, the start and end times of the spring phenology (leaf budding and leaf unfolding) of N. tangutorum advanced during an extremely dry and an extremely wet year, but the duration of phenology was shortened during an extremely wet year and prolonged during an extremely drought-stricken year. The amplitude of variation increased with the increase in simulated precipitation. (2) After the simulated enhancement of precipitation, the start and end times of the phenology (leaf senescence and leaf fall) of N. tangutorum during the autumn advanced in an extremely wet year but was delayed during an extremely dry year, and the duration of phenology was prolonged in both extremely dry and wet years. The amplitude of variation increased with the increase in simulated precipitation. (3) The regulation mechanism of extremely dry or wet years on the spring phenology of N. tangutorum lay in the different degree of influence on the start and end times of leaf budding and leaf unfolding. However, the regulation mechanism of extremely dry or wet years on the autumn phenology of N. tangutorum lay in different reasons. Water stress caused by excessive water forced N. tangutorum to start its leaf senescence early during an extremely wet year. In contrast, the alleviation of drought stress after watering during the senescence of N. tangutorum caused a delay in the autumn phenology during an extremely dry year.

scholarly journals Phenological Differentiation in Sugar Maple Populations and Responses of Bud Break to an Experimental Warming

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 929
Author(s):  
Ping Ren ◽  
Eryuan Liang ◽  
Patricia Raymond ◽  
Sergio Rossi
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Thermal Conditions ◽  
Mean Annual Temperature ◽  
Bud Break ◽  
Spring Phenology ◽  
Additional Degree ◽  
Natural Range ◽  
Bud Phenology ◽  
Different Populations

Species with wide geographical ranges exhibit specific adaptations to local climates, which may result in diverging responses among populations to changing conditions. Climate change has advanced spring phenology worldwide, but questions of whether and how the phenological responses to warming differ among individuals across the natural range of a species remain. We conducted two experiments in January and April 2019, and performed daily observations of the timings of bud break in 1-year-old seedlings of sugar maple (Acer saccharum Marshall) from 25 Canadian provenances at two thermal conditions (14/10 and 18/14 °C day/night temperature) in a controlled environment. Overall, bud break started 6 days from the beginning of the experiments and finished after 125 days. The earlier events were observed in seedlings originating from the colder sites. Bud break was delayed by 4.8 days per additional degree Celsius in the mean annual temperature at the origin site. Warming advanced the timing of bud break by 17–27 days in January and by 3–8 days in April. Similar advancements in bud break were observed among provenances under warming conditions, which rejected our hypothesis that sugar maple populations have different phenological responses to warming. Our findings confirm the differentiation in ecotypes for the process of bud break in sugar maple. In cases of homogenous spring warming across the native range of sugar maple, similar advancements in bud phenology can be expected in different populations.

Sign in / Sign up

Export Citation Format

Share Document