The Formation of Traumatic Rows of Resin Ducts in Larix Decidua and Picea Abies (Pinaceae) as a Result of Wounding Experiments in the Dormant Season

IAWA Journal ◽  
2009 ◽  
Vol 30 (2) ◽  
pp. 199-215 ◽  
Author(s):  
Holger Gärtner ◽  
Ingo Heinrich

Wounding experiments, imitating the impact of geomorphic processes such as rock fall, were performed on Larix decidua Mill. and Picea abies (L.) Karst., before the beginning and at the end of the growing season. This was done to evaluate the timing and spread of traumatic rows of resin ducts (TDs) as a result of wounding during dormancy, when most mass movements occur. All treatments were successful in inducing TDs. However, a high inter- and intra-species variability concerning the timing and position of the TDs was noted. In larch, TDs were formed as first cells after wounding (immediate reaction) only in the vicinity of the wound. In contrast, none of the spruce trees exhibited immediate reactions. Neither larch nor spruce formed continuous TDs around the stem. TDs in larch were more extensive if, in addition, stems were bent before the growing season. In contrast, spruce showed this reaction when bent at the end of the growing season. The results indicate that the varying lengths of the growing seasons at different geographical locations need to be taken into account before an immediate wound reaction can be clearly defined, if an increase of the reliability and accuracy of process reconstructions is aimed for.

2019 ◽  
Author(s):  
Zhen Teng ◽  
Wei Fan ◽  
Huiling Wang ◽  
Xiaoqing Cao ◽  
Xiaoniu Xu

AbstractUnder the circumstance of wetland degradation, we used Biolog EcoPlates™ method to investigate the impact of ecological restoration on the function of topsoil microbial communities by monitoring their metabolic diversity around Chaohu lakeside wetland. Four restoration patterns including reed shoaly land (RL), poplar plantation land (PL), abandoned shoaly grassland (GL) and cultivated flower land (FL) were selected. The result showed a rapid growth trend at the initial stage of incubation, following the fastest change rate at 72 h in both dormant and growing seasons, and the AWCD values of RL pattern was the highest at the detection points of each culture time, while the GL were the lowest. The calculation of diversity indicators also displayed significant lower McIntosh index in dormant season and Shannon-Wiener index in growing season in GL than in the others (P < 0.05). Carbohydrates and carboxylic acids were found to be the dominant substrates used in dormant season, whereas amino acids, polymers and phenolic acids were increasingly utilized by the microbial communities in growing season. We observed soil total potassium as the key factor that significantly affected the utilization efficiency of different carbon sources in both seasons (P < 0.05).


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”.


2014 ◽  
Vol 36 (2) ◽  
pp. 185 ◽  
Author(s):  
Fang Chen ◽  
Keith T. Weber

Changes in vegetation are affected by many climatic factors and have been successfully monitored through satellite remote sensing over the past 20 years. In this study, the Normalised Difference Vegetation Index (NDVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite, was selected as an indicator of change in vegetation. Monthly MODIS composite NDVI at a 1-km resolution was acquired throughout the 2004–09 growing seasons (i.e. April–September). Data describing daily precipitation and temperature, primary factors affecting vegetation growth in the semiarid rangelands of Idaho, were derived from the Surface Observation Gridding System and local weather station datasets. Inter-annual and seasonal fluctuations of precipitation and temperature were analysed and temporal relationships between monthly NDVI, precipitation and temperature were examined. Results indicated NDVI values observed in June and July were strongly correlated with accumulated precipitation (R2 >0.75), while NDVI values observed early in the growing season (May) as well as late in the growing season (August and September) were only moderately related with accumulated precipitation (R2 ≥0.45). The role of ambient temperature was also apparent, especially early in the growing season. Specifically, early growing-season temperatures appeared to significantly affect plant phenology and, consequently, correlations between NDVI and accumulated precipitation. It is concluded that precipitation during the growing season is a better predictor of NDVI than temperature but is interrelated with influences of temperature in parts of the growing season.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1118
Author(s):  
Vladimír Šagát ◽  
Ivan Ružek ◽  
Karel Šilhán ◽  
Pavel Beracko

Picea abies L. Karst is undeniably one of the most important tree species growing in Slovakia. In addition to natural mountain spruce forests, monocultures planted in lower areas are also quite common. In this article, we analyze the climate–growth response differences between these two types of spruce stands in the context of local climate change consequences. The study area representing natural mountain spruce forests is located under Osobitá Mt. (Tatra Mountains, Slovakia), while the analyzed low-lying planted monoculture is situated near Biely kríž (Malé Karpaty Mountains, Slovakia). Temporal variation of the dendroclimatological relationships was expressed by the running Spearman correlation coefficient during the observed period 1961–2018. The results showed crucial differences in the dendroclimatological relationships between the selected study areas. For the natural mountain spruce stand, consistent, weak, and positive correlations to the temperature variables were typical, with negative relationships to precipitation during the growing season. In this case, the negative impact of a recent temperature rise was limited. In contrast, the monoculture reacted to the temperature variation during the growing season with fluctuations, while in the case of precipitation, almost no dependence was found. Such incoherency may be a consequence of worsened health conditions, as well as insufficient resiliency to climate-driven stress. The importance of this paper is in its wide applicability, mainly in forestry.


Author(s):  
А.В. Чудаков ◽  
Д.А. Данилов ◽  
Д.А. Зайцев

Проведено исследование влияния климатических факторов на показатели прироста древостоев сосны (Pinus sylvestris) и ели (Picea abies) естественного происхождения, не затронутых рубками. Объекты исследования – древостои с разной долей участия этих пород в однородных условиях произрастания на почвах с двучленными отложениями. Длительность анализируемого периода составила 54 года, на текущий момент древостои являются спелыми. Была изучена связь прироста со средней температурой воздуха за вегетационный период и суммой осадков за вегетационный период. Анализ связей климата с параметрами древесины хвойных проводили на основе поиска статистически значимых ранговых коэффициентов корреляции между древесно-кольцевыми хронологиями и климатическими факторами в насаждениях с разной долей участия сосны и ели. Вычислялся коэффициент ранговой корреляции Спирмена как количественная оценка связи между исследуемыми явлениями. Ранговый корреляционный анализ позволил на статистически значимом уровне оценить вклад средних температур и суммы осадков по месяцам в формирование макроструктурных элементов древесины сосны и ели. Прослеживается большая метеозависимость элементов годичного прироста древесины ели, чем сосны, в данных условиях. Для соснового элемента смешанных хвойных древостоев наибольшая взаимосвязь с температурными показателями наблюдается в июле–сентябре, тогда как для ели выявлена ярко выраженная зависимость с этим фактором в мае для всех древостоев с ее участием. Проведенное исследование показало, что в зависимости от доли участия ели и сосны образование структурных элементов ксилемы годичного прироста имеет разную степень по силе вязи со средними температурами и суммой осадков по месяцам вегетационного периода. A study was carried out on the impact of climatic factors on the increment rates of pine (Pinus sylvestris L.) and spruce (Picea abies (L.) Karst.) stands of natural origin, not affected by forestry impact. Tree stands with different participation of these species in similar growth conditions on binary deposits soils were reviewed. The duration of the analyzed period was 54 years, at the present time stands are mature. The connection between the growth and average air temperature during the growing season and the amount of precipitation during the growing season was studied. The analysis of climate relationships with coniferous wood parameters was carried out on the basis of searching statistically significant rank coefficients of correlation between wood-ring chronologies and climate factors in stands with different participation shares of pine and spruce. Spearman's rank correlation coefficient was calculated as a quantitative evaluation of the connection between the observed effects. Rank correlation analysis allowed to estimate at statistically significant level the contribution of average temperatures and the sum of monthly precipitation on the formation of macrostructural elements of pine and spruce wood. There is a higher meteorological dependence on the increment rate of spruce wood than pine wood in the given conditions. For the pine element of mixed coniferous trees the greatest correlation of increment with temperature indices is observed in July-September months, while for the spruce a marked dependence with this factor was revealed in May month for all stands with spruce participation. The study showed that depending on the share of conifers, the formation of structural elements of the xylem has a different strength of the relationship with average temperatures and the amount of precipitation in the months of the growing season.


1988 ◽  
Vol 18 (6) ◽  
pp. 669-674 ◽  
Author(s):  
James W. McMinn ◽  
Wade L. Nutter

Oak–pine stands in the Upper Piedmont of Georgia were whole-tree harvested to 10-cm and 2.5-cm lower dbh limits in both the dormant and early growing seasons. Pine natural regeneration and hardwood coppice were observed through five growing seasons. Dormant-season harvesting resulted in pine stocking of over 90% and 60% for the 2.5-cm and 10-cm limit, respectively. Growing-season harvesting resulted in initial pine stocking of less than 15%. Initial coppice coverage was greatest after dormant-season harvesting, but due to pine competition was approximately equal to the growing-season harvest coverage after 5 years. Residual stems with total basal areas less than 7 m2/ha after 10-cm limit cutting suppressed growth of both the pine regeneration and the hardwood coppice. Results demonstrate that modifications in harvesting alone can substantially influence subsequent species composition and stand development.


Poljoprivreda ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 25-31
Author(s):  
Goran Krizmanić ◽  
Tihomir Čupić ◽  
Snežana V. Jovanović ◽  
Monika Marković ◽  
Andrija Brkić ◽  
...  

The spring field pea is one of the most important coarse legumes. This study was carried out to investigate the response of a spring field pea variety to three plant densities (50, 100, and 150 plant m-2) during the 2017 and 2019 growing seasons in eastern Croatia. The field study was set up as a Randomized Complete Block Design (RCBD) in four replications. The results have demonstrated a significant effect of the plant densities and the growing seasons on the seed yield and on the following yield components: plant height and the number of pods/plant. The effect of plant densities on the number of seeds/pod and the thousand-seed weight was not significant. As for a growing season, the highest seed yield, plant height, the number of pods/plant were obtained in the second growing season. Furthermore, a maximum seed yield was recorded at the 150-plant m-2 plant density. This study has demonstrated that planting the spring field pea at different plant densities significantly modifies the spring field pea yield, plant height and number of pods/plant.


Author(s):  
V.H. Moldovan ◽  
Zh.A. Moldovan ◽  
S.I. Sobchuk

Purpose. To study of the influence of sowing terms on plant growth and development, formation of indicators of individual productivity and seed yield by soybean varieties with different vegetation period in conditions of the western Forest-Steppe of Ukraine. Methods. Field experiment, calculation and weight, mathematical statistics. Results. Weather conditions in the years of the research were characterized by high average daily temperatures against the background of uneven distribution of precipitation by phases of soybean development, which together with the studied factor had a significant impact on the growth and development of soybean plants and seed yield formation. It was found that the studied soybean varieties with different growing seasons react differently to growing conditions. The timing of sowing significantly affects the height of attachment of the lower bean, the number of beans per plant and seeds in the bean, the weight of 1000 seeds and the weight of seeds per 1 plant. However, they have almost no effect on the number of seeds in the bean. It was investigated that the soybean variety Diadema Podillya forms the highest yields at the optimal and late sowing dates, while the soybean of the KiVin, Knyazhna, Khutoryanochka and Triada varieties – at the late sowing period (second decade of May). The increase in seed yield compared to sowing in the optimal time (first decade of May) was 6.6%, 3.1%, 13.8% and 9.6%, respectively. Conclusions. Sowing terms in interaction with the weather conditions of the growing season, have a significant impact on the formation of indicators of individual productivity and seed yield of soybean varieties with different growing seasons. That is why in the conditions of climate change, uneven moisture supply during the growing season and the emergence of new varieties it is advisable to continue research to study the impact of sowing dates, in interaction with other factors, on the formation of individual productivity and yield of soybean seeds.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hunter A. Hammock ◽  
Dean A. Kopsell ◽  
Carl E. Sams

The use of light-emitting diodes (LEDs) in commercial greenhouse production is rapidly increasing because of technological advancements, increased spectral control, and improved energy efficiency. Research is needed to determine the value and efficacy of LEDs in comparison to traditional lighting systems. The objective of this study was to establish the impact of narrowband blue (B) and red (R) LED lighting ratios on flavor volatiles in hydroponic basil (Ocimum basilicum var. “Genovese”) in comparison to a non-supplemented natural light (NL) control and traditional high-pressure sodium (HPS) lighting. “Genovese” basil was chosen because of its high market value and demand among professional chefs. Emphasis was placed on investigating concentrations of important flavor volatiles in response to specific ratios of narrowband B/R LED supplemental lighting (SL) and growing season. A total of eight treatments were used: one non-supplemented NL control, one HPS treatment, and six LED treatments (peaked at 447 nm/627 nm, ±20 nm) with progressive B/R ratios (10B/90R, 20B/80R, 30B/70R, 40B/60R, 50B/50R, and 60B/40R). Each SL treatment provided 8.64 mol ⋅ m−2 ⋅ d–1 (100 μmol ⋅ m–2 ⋅ s–1, 24 h ⋅ d–1). The daily light integral (DLI) of the NL control averaged 9.5 mol ⋅ m−2 ⋅ d–1 during the growth period (ranging from 4 to 18 mol ⋅ m−2 ⋅ d–1). Relative humidity averaged 50%, with day/night temperatures averaging 27.4°C/21.8°C, respectively. Basil plants were harvested 45 days after seeding, and volatile organic compound profiles were obtained by gas chromatography–mass spectrometry. Total terpenoid concentrations were dramatically increased during winter months under LED treatments, but still showed significant impacts during seasons with sufficient DLI and spectral quality. Many key flavor volatile concentrations varied significantly among lighting treatments and growing season. However, the concentrations of some compounds, such as methyl eugenol, were three to four times higher in the control and decreased significantly for basil grown under SL treatments. Maximum concentrations for each compound varied among lighting treatments, but most monoterpenes and diterpenes evaluated were highest under 20B/80R to 50B/50R. This study shows that supplemental narrowband light treatments from LED sources may be used to manipulate secondary metabolic resource allocation. The application of narrowband LED SL has great potential for improving overall flavor quality of basil and other high-value specialty herbs.


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