scholarly journals Xylem Plasticity in Pinus pinaster and Quercus ilex Growing at Sites with Different Water Availability in the Mediterranean Region: Relations between Intra-Annual Density Fluctuations and Environmental Conditions

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 379
Author(s):  
Angela Balzano ◽  
Giovanna Battipaglia ◽  
Paolo Cherubini ◽  
Veronica De Micco

Fluctuations in climatic conditions during the growing season are recorded in Mediterranean tree-rings and often result in intra-annual density fluctuations (IADFs). Dendroecology and quantitative wood anatomy analyses were used to characterize the relations between the variability of IADF traits and climatic drivers in Pinus pinaster Aiton and Quercus ilex L. growing at sites with different water availability on the Elba island in Central Italy. Our results showed that both species present high xylem plasticity resulting in the formation of L-type IADFs (L-IADFs), consisting of earlywood-like cells in latewood. The occurrence of such IADFs was linked to rain events following periods of summer drought. The formation of L-IADFs in both species increased the hydraulic conductivity late in the growing season, due to their larger lumen area in comparison to “true latewood”. The two species expressed greater similarity under arid conditions, as unfavorable climates constrained trait variation. Wood density, measured as the percentage of cell walls over total xylem area, IADF frequency, as well as conduit lumen area and vessel frequency, specifically in the hardwood species, proved to be efficient proxies to encode climate signals recorded in the xylem. The response of these anatomical traits to climatic variations was found to be species- and site-specific.

2007 ◽  
Vol 37 (10) ◽  
pp. 1915-1923 ◽  
Author(s):  
F. Campelo ◽  
E. Gutiérrez ◽  
M. Ribas ◽  
C. Nabais ◽  
H. Freitas

The influence of climatic factors on tree-ring width and the formation of double rings was studied in Quercus ilex L. growing in a coppice stand left unmanaged for 22 years. Ten trees were felled and discs were taken every 30 cm from bole and dominant branches. Dendrometer bands were installed on 10 nearby trees and the data recorded were used to confirm the accuracy of our tree-ring identification. They were also used to relate the seasonal radial growth pattern to double-ring formation. Double rings were frequent and occurred consistently along the stem. Two types of double rings could be recognized according to their width: type I, with the extra growth band accounting for approximately 50% of the tree ring; and type II, with a narrow extra growth band. Type I double rings were formed when approximately 1/2 of the growing-season precipitation occurred during the second growth period of the season and after the summer drought. Type II double rings occurred when approximately 1/3 of the precipitation in the growing season occurred after the summer drought. The formation of double rings was triggered by rainfall in summer and the extra growth-band width was related to summer and autumn environmental conditions. Double rings in Q. ilex can potentially be used in dendroclimatological studies, as they are formed in response to climatic conditions within the growing season.


2022 ◽  
Vol 3 (1) ◽  
pp. 01-07
Author(s):  
Gusti Rusmayadi ◽  
Umi Salawati ◽  
Dewi Erika Adriani

The determining factor for the success of agricultural cultivation in tidal swampland is water availability, which fluctuates throughout the plant's growth. The availability of water for oranges has a significant role in the final production of the product. In Indonesia, there are three types of rain patterns with variations in the growing season related to water availability: the rainy season between October and March and the dry season between April and September. Climate extremes such as drought (El-Niño) and wetness (La-Niña) fluctuate dynamically, impact shifts at the beginning and end of the growing season, and hurt citrus crop productivity. Therefore, an analysis of rice planting time in tidal swampland in Barito Kuala under extreme climatic events was carried out. The research was conducted in September – December 2020 with the survey method. The data was dug in-depth on the research respondents: citrus farmers, fruit traders, and related agencies. The number of samples was 90 people (45 male farmers and 45 female farmers). Two different villages were surveyed in each sub-district according to the type of tidal land, namely Marabahan sub-district (SP1 village and SP2 village), type A, Mandastana (Karang Indah village and Karang Bunga village) type B, and Cerbon sub-district. (Village of Simpang Nungki and Sungai Kambat) Type C. Planting time in tidal land begins after the amount of rainwater is sufficient to dissolve the iron content in the water. The probability of an El-Niño occurrence with an intensity of 1, 2, 3, and 4 years has the highest frequency of occurrence—respectively 3, 3, 5, and 3 times with probability around 16.7% to 27.8%. Meanwhile, La-Nia with an intensity of once a year with the highest frequency eight times with a 40.0% chance. La-Nia events coexist with El-Nio 15 times, and generally, El-Nio precedes La-Nia by about 44%. The cropping pattern in tidal swampland shows high resistance to climate change. Namely, the planting time has not changed much for decades under different climatic conditions.


Author(s):  
N.V. Sergeev ◽  
◽  
A.Yu. Pivkin

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.


Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 290
Author(s):  
Koffi Djaman ◽  
Curtis Owen ◽  
Margaret M. West ◽  
Samuel Allen ◽  
Komlan Koudahe ◽  
...  

The highly variable weather under changing climate conditions affects the establishment and the cutoff of crop growing season and exposes crops to failure if producers choose non-adapted relative maturity that matches the characteristics of the crop growing season. This study aimed to determine the relationship between maize hybrid relative maturity and the grain yield and determine the relative maturity range that will sustain maize production in northwest New Mexico (NM). Different relative maturity maize hybrids were grown at the Agricultural Science Center at Farmington ((Latitude 36.69° North, Longitude 108.31° West, elevation 1720 m) from 2003 to 2019 under sprinkler irrigation. A total of 343 hybrids were grouped as early and full season hybrids according to their relative maturity that ranged from 93 to 119 and 64 hybrids with unknown relative maturity. The crops were grown under optimal management condition with no stress of any kind. The results showed non-significant increase in grain yield in early season hybrids and non-significant decrease in grain yield with relative maturity in full season hybrids. The relative maturity range of 100–110 obtained reasonable high grain yields and could be considered under the northwestern New Mexico climatic conditions. However, more research should target the evaluation of different planting date coupled with plant population density to determine the planting window for the early season and full season hybrids for the production optimization and sustainability.


Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 95
Author(s):  
Yuan Gong ◽  
Christina L. Staudhammer ◽  
Susanne Wiesner ◽  
Gregory Starr ◽  
Yinlong Zhang

Understanding plant phenological change is of great concern in the context of global climate change. Phenological models can aid in understanding and predicting growing season changes and can be parameterized with gross primary production (GPP) estimated using the eddy covariance (EC) technique. This study used nine years of EC-derived GPP data from three mature subtropical longleaf pine forests in the southeastern United States with differing soil water holding capacity in combination with site-specific micrometeorological data to parameterize a photosynthesis-based phenological model. We evaluated how weather conditions and prescribed fire led to variation in the ecosystem phenological processes. The results suggest that soil water availability had an effect on phenology, and greater soil water availability was associated with a longer growing season (LOS). We also observed that prescribed fire, a common forest management activity in the region, had a limited impact on phenological processes. Dormant season fire had no significant effect on phenological processes by site, but we observed differences in the start of the growing season (SOS) between fire and non-fire years. Fire delayed SOS by 10 d ± 5 d (SE), and this effect was greater with higher soil water availability, extending SOS by 18 d on average. Fire was also associated with increased sensitivity of spring phenology to radiation and air temperature. We found that interannual climate change and periodic weather anomalies (flood, short-term drought, and long-term drought), controlled annual ecosystem phenological processes more than prescribed fire. When water availability increased following short-term summer drought, the growing season was extended. With future climate change, subtropical areas of the Southeastern US are expected to experience more frequent short-term droughts, which could shorten the region’s growing season and lead to a reduction in the longleaf pine ecosystem’s carbon sequestration capacity.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1726
Author(s):  
Nasr H. Gomaa ◽  
Ahmad K. Hegazy ◽  
Arafat Abdel Hamed Abdel Latef

Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known “stress-gradient hypothesis”.


2021 ◽  
Vol 5 (1) ◽  
pp. 13-22
Author(s):  
V. V. Gamayunova ◽  
L. H. Khonenko ◽  
M. I. Fedorchuk ◽  
O. A. Kovalenko

The cultivation expediency of more drought-resistant crops, in particular sorghum, millet, false flax, safflower and others, instead of sunflower in the area of the Southern Steppe of Ukraine is substantiated. This is, first of all, required by climate change both in Ukraine and in the world. Since 2004, researches of field crops were carried out in the conditions of the Educational and Scientific Practical Center of the Mykolaiv National Agrarian University. Soil phase is the southern chernozem with humus content in the 0–30 cm soil layer which consist of 2.96–3.21 %, with medium and high level of availability of mobile phosphorus and potassium and low – mobile nitrogen. Experiments with soriz (Oksamyt hybrid) were conducted during 2004–2006, millet (Tavriiske, Kostantynivske, Skhidnevarieties) in 2008–2010, grain sorghum (Stepovyi 5 hybrid) in 2014–2016, safflower dye (Lahidnyi variety) in 2017–2019. The years of research differed significantly in temperature and even more in the amount of precipitation before sowing and during the growing season of crops. However, the weather conditions were typical of the Southern Steppe zone of Ukraine. It is established that all studied drought-resistant crops respond positively to nutrition optimization – the level of yield and quality of grain or seeds increases. It was found that the soriz productivity depending on the application of fertilizers and sowing dates increased by 37.6–39.2 %, millet –by 33.3–41.6 %, grain sorghum depending on the background of nutrition and growing conditions – by 8.2–33.2 %, dye safflower – by 11.1–64.6 %. It was determined that the optimization of nutrition of cultivated crops allows to increase their resistance to adverse conditions and productivity in the case of application of low doses of the mineral fertilizers before sowing, pre-sowing treatment of seeds, and growth-regulating chemical application of plants on the main stages of the growing season. Key words: drought-resistant plants, climatic conditions, nutrition optimization, yield, crop quality, varieties, sowing dates.


2018 ◽  
Vol 124 (4) ◽  
pp. 567-579 ◽  
Author(s):  
Matthew Haworth ◽  
Giovanni Marino ◽  
Ezio Riggi ◽  
Giovanni Avola ◽  
Cecilia Brunetti ◽  
...  

Abstract Background and Aims The development of Arundo donax as a biomass crop for use on drought-prone marginal lands in areas with warm to hot climates is constrained by the lack of variation within this species. We investigated the effect of morphological and physiological variation on growth and tolerance to drought under field conditions in three ecotypes of A. donax collected from habitats representing a climate gradient: a pre-desert in Morocco, a semi-arid Mediterranean climate in southern Italy and a warm sub-humid region of central Italy. Methods The three A. donax ecotypes were grown under irrigated and rain-fed conditions in a common garden field trial in a region with a semi-arid Mediterranean climate. Physiological and morphological characteristics, and carbohydrate metabolism of the ecotypes were recorded to establish which traits were associated with yield and/or drought tolerance. Key Results Variation was observed between the A. donax ecotypes. The ecotype from the most arid habitat produced the highest biomass yield. Stem height and the retention of photosynthetic capacity later in the year were key traits associated with differences in biomass yield. The downregulation of photosynthetic capacity was not associated with changes in foliar concentrations of sugars or starch. Rain-fed plants maintained photosynthesis and growth later in the year compared with irrigated plants that began to senescence earlier, thus minimizing the difference in yield. Effective stomatal control prevented excessive water loss, and the emission of isoprene stabilized photosynthetic membranes under drought and heat stress in A. donax plants grown under rain-fed conditions without supplementary irrigation. Conclusions Arundo donax is well adapted to cultivation in drought-prone areas with warm to hot climates. None of the A. donax ecotypes exhibited all of the desired traits consistent with an ‘ideotype’. Breeding or genetic (identification of quantitative trait loci) improvement of A. donax should select ecotypes on the basis of stem morphology and the retention of photosynthetic capacity.


2014 ◽  
Vol 44 (4) ◽  
pp. 175 ◽  
Author(s):  
Daniele Duca ◽  
Giuseppe Toscano ◽  
Ester Foppa Pedretti ◽  
Giovanni Riva

The use of renewable energies as alternative to fossil fuels has value from different points of view and has effects at environmental, social and economic level. These aspects are often connected to each other and together define the overall sustainability of bioenergy. At European level, the Directive 2009/28/EC gives the basic criteria for the estimation of sustainability of biofuels and indicates a minimum threshold of 35% of greenhouse gas saving for a biofuel in order to be considered sustainable. The Directive gives the possibility to identify standard regional values for the cultivation steps that could be utilized for the certification. This paper aims to give a contribution to the definition of these values considering the RED methodology applied to the sunflower cropped in central Italy which is characterized by a hilly landscape and not-irrigated crops. To determine input and output of sunflower cultivation in the central Italy, the results of PROBIO project, carried out by the Authors, were used. The sustainability of biodiesel produced from sunflower grown in central Italy is variable and depends on the nitrogen input and seasonal climatic conditions that affect the yields. The greenhouse gases savings of the Italian chain is 40% in average, greater than the required 35% and would be possible to assign this value as standard to the biofuel chain <em>biodiesel from sunflower cultivated in central Italy</em>. Using an averaged regional standard value guards against the possibility of considering unsustainable harvesting in unfavourable years and seeing it overestimated in the favourable ones.


2009 ◽  
Vol 6 (7) ◽  
pp. 1167-1180 ◽  
Author(s):  
A.-V. Lavoir ◽  
M. Staudt ◽  
J. P. Schnitzler ◽  
D. Landais ◽  
F. Massol ◽  
...  

Abstract. The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control). In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2) due to a more pronounced summer drought period in this respective year. We observed a significant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no significant effect on monoterpene emission was observed between normal and additional drought treatments, despite a significant effect on leaf water potential and photochemical efficiency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought significantly reduces monoterpene fluxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes.


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