scholarly journals Functional responses of recently emerged seedlings of an endemic Mexican oak (Quercus eduardii) under climate change conditions

2018 ◽  
Vol 96 (4) ◽  
pp. 582
Author(s):  
Ernesto I. Badano ◽  
Francisco A. Guerra-Coss ◽  
Sandra M. Gelviz-Gelvez ◽  
Joel Flores ◽  
Pablo Delgado-Sánchez
Keyword(s):  
Climate Change ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Growing Season ◽  
Climatic Conditions ◽  
Tree Seedlings ◽  
Functional Responses ◽  
Climate Change Simulation ◽  
Survival And Growth ◽  
Growth Of Seedlings

<p><strong>Background: </strong>Climate change will increase temperature and reduce rainfall across temperate forests of Mexico. This can alter tree establishment dynamics within forest and in neighbouring man-made clearings.</p><p><strong>Hypotheses:</strong> Climate change will reduce emergence and survival of tree seedlings, and surviving plants will display functional responses matching with these changes. These effects should be more noticeable in clearings due to the lack of canopy cover.</p><p><strong>Studied species</strong>: <em>Quercus eduardii</em> (Fagaceae, section <em>Lobatae</em>) an oak species endemic to Mexico.</p><p><strong>Study site and years of study</strong>: Tree growing season 2015-2016 (rainy season) in a mature oak forest and a neighbouring clearing in Sierra de Álvarez, state of San Luis Potosí.</p><p><strong>Methods: </strong>In both habitats, we established control plots (under current climatic conditions) and climate change simulation plots (increased temperature and reduced rainfall). At the beginning of the growing season, we sowed acorns of <em>Q. eduardii</em> in these plots and monitored the emergence, survival and growth of seedlings. At the end of the growing season, we assessed functional responses on surviving seedlings.</p><p><strong>Results:</strong> Seedling emergence and survival were lower in climate change plots from both habitats. However, differences in survival between climate treatments were larger within the forest. Seedlings from climate change plots displayed functional responses indicating higher levels of thermal and water stress.</p><p><strong>Conclusions: </strong>This study indicates that climate change will constrain tree recruitment in Mexican oak forests. However, contrary to our expectations, it seems that these effects will be higher within forests than in man-made clearings.</p>

scholarly journals The Influence of Climate Change on Oat Productivity in the Steppe Zone of Ukraine

2020 ◽  
Keyword(s):  
Climate Change ◽  
Seedling Emergence ◽  
Growing Season ◽  
Vegetation Period ◽  
Steppe Zone ◽  
Climatic Conditions ◽  
Photosynthetic Productivity ◽  
Climatic Scenarios ◽  
The Impact ◽  
Yield Of Oats

Purpose. To assess the impact of climate change on oat productivity in the steppe zone of Ukraine. Methods. Statistical, mathematical modeling. Results. It is established that the seed sowing and of seedling emergence will be postponed to an earlier date. More favorable conditions are expected for the formation of seedling emergence, growth and development of plants during the period of "seedling - heading". Reduced background temperature will lead to a decrease in the value of total evaporation and a decrease in moisture demand by 47–58 mm. The moisture content of the first vegetation period will be significantly higher than in the middle perennial years. Agroclimatic conditions of the second half of the vegetation period of oats will develop at low temperatures and uneven moisture across the territory. The demand for moisture will increase everywhere by 12–28 mm. The supply of moisture will decrease. Using the model of the formation of the yield of agricultural crops, the influence of changes in the agro-climatic conditions of the growing season on the indicators of photosynthetic productivity of oat crops and the formation of the yield was assessed. Conclusions. It was concluded that a possible increase in the yield of oats in the Steppe zone of Ukraine under the implementation of climatic scenarios and early sowing terms. Changes in agroclimatic conditions in the implementation of climatic scenarios will lead to changes in the photosynthetic activity of oat crops: the relative leaf area will increase, the increase in total plant mass will increase, the photosynthetic potential of crops will grow during the growing season. Proposed cartographic schemes of the expected yield of oats in the Steppe zone of Ukraine.

scholarly journals Climate change effects on early stages of Quercus ariifolia (Fagaceae), an endemic oak from seasonally dry forests of Mexico

2019 ◽  
Author(s):  
Ernesto I. Badano ◽  
Francisco A. Guerra-Coss ◽  
Erik J. Sánchez-Montes de Oca ◽  
Carlos I. Briones-Herrera ◽  
Sandra M. Gelviz-Gelvez
Keyword(s):  
Climate Change ◽  
Functional Traits ◽  
Rainy Season ◽  
Extinction Risk ◽  
Seedling Emergence ◽  
Dry Forest ◽  
Tree Seedlings ◽  
Dry Forests ◽  
Tree Recruitment ◽  
Seasonally Dry

Background and Aims: Tree recruitment in seasonally dry forests occurs during the rainy season. However, higher temperatures and reduced rainfalls are expected in these ecosystems because of climate change. These changes could induce drought conditions during the rainy season and affect tree recruitment. Plants subjected to thermal or water stress often display morphological and physiological shifts addressed to prioritize their survival. If recently emerged tree seedlings display these responses, this could improve their development during the rainy season and increase their survival chances. Our aim was to test whether recently emerged oak seedlings display these responses.Methods: We performed a field experiment with Quercus ariifolia, an oak species endemic to seasonally dry forests of central Mexico. At the beginning of the rainy season (September 2016), we sowed acorns of this species in control plots under the current climate and plots in which climate change was simulated by increasing temperature and reducing rainfall (CCS plots). Seedling emergence and survival were monitored every seven days during the rainy season (until January 2017). At the end of the experiment, we measured several functional traits on surviving seedlings and compared them between controls and CCS plots.Key results: Higher temperature and lower rainfall generated water shortage conditions in CCS plots. This did not affect emergence of seedlings but reduced their survival. Seedlings that survived in CCS plots displayed shifts in their functional traits, which matched with those of plants subjected to thermal and water stress.Conclusions: Our results suggest that climate change can increase the extinction risk of Q. ariifolia in seasonally dry forest of Mexico by reducing the survival of its offspring. Nevertheless, the results also suggest that seedlings developed under climate change conditions can display functional shifts that could confer them tolerance to increased drought.

scholarly journals Effect of climate change on burley tobacco crop calendars

2021 ◽  
Vol 74 (1) ◽  
Author(s):  
Jeannette del Carmen Zambrano Nájera ◽  
Oscar Ortega
Keyword(s):  
Climate Change ◽  
Unit Area ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Water Requirements ◽  
Burley Tobacco ◽  
The North ◽  
Climate Change Simulation ◽  
Optimal Information ◽  
Tobacco Cultivation

In Colombia, tobacco cultivation is an important generator of employment and income for farmers; however it faces different problems as low crop yield compared to other countries; specifically, in the north of the country, where the climatic conditions are less favorable and the productivity is lower than other areas of the country due to low mechanization. In order to improve the tobacco yield per hectare in the municipality of Ovejas, this research aimed to determine the water requirements of burley tobacco cultivation under conditions of climate variability to obtain optimal information for crop calendars. Water requirements of burley tobacco were determined using the crop water requirement equation. This calculation ethod was programmed in Python to automate the generation of maps, developing a tool that allowed a detailed analysis per unit area per week. Based on the results obtained, weeks 17 and 18 of the year (last week of April and first week of May, respectively) are proposed as optimal planting times, since the cycles of crops planted in this period showed precipitation surplus in the initial phase of cultivation, which is a critical phase for their development. Climate change simulation showed that crops must be continuously monitored in order to adapt to new weather conditions.

scholarly journals High resistance to climatic variability in a dominant tundra shrub species

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6967 ◽  
Author(s):  
Victoria T. González ◽  
Mikel Moriana-Armendariz ◽  
Snorre B. Hagen ◽  
Bente Lindgård ◽  
Rigmor Reiersen ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resistance ◽  
Climatic Variability ◽  
Growing Season ◽  
Climatic Conditions ◽  
Vegetative Cover ◽  
Growth And Survival ◽  
Growing Season Length ◽  
Temperature And Precipitation ◽  
Precipitation Regimes

Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially having contrasting effects on their growth and survival, can determine the future of tundra plant communities under climate change. In our study, we evaluated the effects of several spring/summer and winter climatic variables (i.e., summer temperature, growing season length, growing degree days, and number of winter freezing days) on the resistance of the dwarf shrub Empetrum nigrum. We measured over six years the ability of E. nigrum to keep a stable shoot growth, berry production, and vegetative cover in five E. nigrum dominated tundra heathlands, in a total of 144 plots covering a 200-km gradient from oceanic to continental climate. Overall, E. nigrum displayed high resistance to climatic variation along the gradient, with positive growth and reproductive output during all years and sites. Climatic conditions varied sharply among sites, especially during the winter months, finding that exposure to freezing temperatures during winter was correlated with reduced shoot length and berry production. These negative effects however, could be compensated if the following growing season was warm and long. Our study demonstrates that E. nigrum is a species resistant to fluctuating climatic conditions during the growing season and winter months in both oceanic and continental areas. Overall, E. nigrum appeared frost hardy and its resistance was determined by interactions among different season-specific climatic conditions with contrasting effects.

Ecological Studies of the Endangered Rutidosis leptorrhynchoides. II. Patterns of Seedling Emergence and Survival in a Native Grassland

1995 ◽  
Vol 43 (1) ◽  
pp. 13 ◽  
Author(s):  
JW Morgan
Keyword(s):  
Soil Moisture ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Moisture Stress ◽  
Seedling Mortality ◽  
Themeda Triandra ◽  
Established Plant ◽  
Survival And Growth ◽  
Growth Of Seedlings

The emergence, survival and growth of seedlings of the endangered Rutidosis leptorrhynchoides F.Muell. were followed in a Themeda triandra grassland during 1991 and 1992. The effect of summer irrigation on seedling survival was also investigated. Seedling emergence occurred in both years within 2 weeks of the 'autumn break' when soil moisture rose above 20%. Ninety percent of emergence was observed within 4 weeks of the onset of germination and 87% of seedlings were within 20 cm of an established plant. No emergence was observed after 8 weeks. Thirteen percent of the 1991 cohort survived for 14 months. Mortality of most seedlings (63%) was attributed to soil moisture stress in summer. Small seedlings (Ͱ4 3 leaves) were no more susceptible to drought than larger seedlings. Seventy two percent of the 1991 cohort produced four leaves before subsequently dying. In 1992, however, most early seedling mortality was amongst cotyledonary seedlings. No seedlings flowered in their first year. Above-ground growth was slow and by 14 months, 60% of surviving seedlings had seven or fewer live leaves. Irrigation in a year of below-average rainfall had no significant effect on the survival and growth of seedlings. This suggests that seedling recruitment is not restricted to climatically favourable years (i.e. is not episodic) but rather, is potentially on-going provided suitable microsites are available for seedling survival.

scholarly journals Long-term tendencies in climate change of the Urals due to global warming

2020 ◽  
Vol 222 ◽  
pp. 05001
Author(s):  
A.A. Vasiliev ◽  
L.V. Ufimtseva ◽  
N.V. Glaz ◽  
D.Yu. Nokhrin
Keyword(s):  
Climate Change ◽  
Irrigation System ◽  
Growing Season ◽  
Climatic Conditions ◽  
Cultivated Plants ◽  
Hydrothermal Coefficient ◽  
Chelyabinsk Region ◽  
Annual Amount ◽  
Observation Period

During the observation period, the annual air temperature increased: in Yekaterinburg (1832-2018) by 3,1°C, in Zlatoust (1881-2018) by 2,2°C, in Kurgan (1894-2018) by 2,2°C and in Shadrinsk (1894-2018) by 2,1°C. The analogical climate change was noted for the period 1966-2018. The strongest warming is observed in winter (by 2,3-3,0°C), the weakest warming is observed in spring (by 0,8-1,7°C). We noted an increase the annual amount of precipitation in Ivdel (by 68,2 mm), Shadrinsk (by 50,9 mm) and Krasnoufimsk (by 43,6 mm). Also marked an increase the amount of precipitation during the growing season in Ivdel (by 43,9 mm), Shadrinsk (by 42,8 mm) and Krasnoufimsk (by 26,8 mm). The annual amount of precipitation increased in Chelyabinsk and Yekaterinburg, but the amount of precipitation during the growing season decreased in Kurgan. Favorable changes in the agro-climatic conditions of growing season were noted in Shadrinsk and Zlatoust. Unfavorable changes in hydrothermal coefficient for cultivated plants were noted in Chelyabinsk, Kurgan, Troitsk, Yekaterinburg and Bredy. Identified the need to introduce an irrigation system for cultivated plants of the southern districts (Chelyabinsk region).

scholarly journals Spatiotemporal variations in groundwater and evaporative demand drive ecophysiological functioning of a phreatophyte in drylands

2021 ◽  
Author(s):  
Maria Trinidad Torres-García ◽  
Maria Jacoba Salinas-Bonillo ◽  
Jamie R. Cleverly ◽  
Manuel Pacheco-Romero ◽  
Javier Cabello
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Leaf Area ◽  
Anthropogenic Activities ◽  
Growing Season ◽  
Spatiotemporal Variability ◽  
Limiting Factor ◽  
Functional Responses ◽  
Multiple Trait ◽  
Evaporative Demand

Abstract Water is the main limiting factor for groundwater-dependent ecosystems (GDEs) in drylands. Predicted climate change (precipitation reductions and temperature increases) and anthropogenic activities such as groundwater drawdown jeopardize the structure and functioning of these ecosystems, presenting new challenges for their management. We developed a trait-based analysis to examine the spatiotemporal variability in the ecophysiology of Ziziphus lotus, a phreatophyte that dominates one of the few terrestrial GDEs of semiarid regions in Europe. We assessed morpho-functional and hydraulic traits along a naturally occurring gradient of depth-to-groundwater (DTGW, 2–25 m) in a coastal aquifer, and throughout the growing season of the species. Increasing DTGW and salinity negatively affected photosynthetic and transpiration rates, increasing plant water stress (lower predawn and midday water potential), and positively affected Huber value (sapwood cross-sectional area per leaf area), reducing leaf area and likely, plant hydraulic demand. However, higher atmospheric evaporative demand fostered higher transpiration rates and water stress. Differences in climatic conditions throughout the growing season drove temporal variability in Z. lotus responses along the DTGW gradient, with warmer and drier conditions promoting carbon assimilation and water loss more intensively at shallow water tables. This multiple-trait analysis allowed us to identify plant ecophysiological thresholds related to the increase in DTGW and evaporative demand during the growing season. These findings highlight the existence of tipping points in the ecophysiological functioning of phreatophytic plants in drylands, which contribute to disentangle the functional responses of the related GDEs under groundwater detriment because of climate change effects.

Impact of sowing, canopy cover and litter on seedling dynamics of two Polylepis species at upper tree lines in central Ecuador

2007 ◽  
Vol 23 (3) ◽  
pp. 309-318 ◽  
Author(s):  
Arne Cierjacks ◽  
Juan Enrique Iglesias ◽  
Karsten Wesche ◽  
Isabell Hensen
Keyword(s):  
Linear Models ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Canopy Cover ◽  
Climatic Conditions ◽  
First Year ◽  
Tree Line ◽  
Seedling Dynamics ◽  
Log Linear

Failure of reproduction is hypothesized as being a main reason for the formation of upper tree lines but there is, as yet, little supportive evidence of such. This study investigates the effects of experimental sowing, canopy cover and litter depth on seedling emergence and survival of Polylepis incana and Polylepis pauta at the upper distribution limit of the species in the Páramo de Papallacta, central Ecuador. We established 18 study plots located in the interior, at the edge and at the exterior of closed forests at the upper tree line and analysed seedling dynamics for 1 y following experimental sowing with four different litter treatments. For both species, seedling numbers were significantly higher in the forest interior than outside, and higher in the treatments with the litter layer removed. In P. pauta, sowing significantly increased seedling number, which was more pronounced within and at the edge of the forest than outside. In contrast, there was no impact of sowing on seedling emergence in P. incana. First-year seedling survival and mean growth rate per month were low in both species. Log-linear models did not reveal significant interactions between survival and canopy cover or litter removal. Our data show that seedling recruitment is limited at the upper tree line – presumably due to extreme climatic conditions – which indicates the importance of constraints in sexual regeneration for tree-line formation in central Ecuador.

Experience of soybean cultivation in the Kaluga Department of Agricultural Machinery SC.

2020 ◽  
Author(s):  
N.V. Sergeev ◽  
◽  
A.Yu. Pivkin
Keyword(s):  
Seed Yield ◽  
Growing Season ◽  
Climatic Conditions ◽  
High Yield ◽  
Soybean Variety ◽  
Agricultural Machinery ◽  
Kaluga Region ◽  
High Seed Yield

The experience of cultivation of soybeans in SC "Agricultural machinery" of the Kaluga region on an area of 190 hectares shows that the soybean variety Alaska is sufficiently adapted to the soil and climatic conditions of this region, provides a high seed yield (up to 32 c / ha) and a high yield (up to 1344 kg / ha) relatively inexpensive protein. However, this variety has a long growing season (95-105 days) and therefore desiccation of crops is required for harvesting for seeds.

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