Ethylene production and morphological adaptation of woody plants to flooding

1984 ◽  
Vol 62 (8) ◽  
pp. 1659-1664 ◽  
Author(s):  
Z. C. Tang ◽  
T. T. Kozlowski

Seedlings of Ulmus americana, Fraxinus pennsylvanica, Melaleuca quinquenervia, and Eucalyptus camaldulensis exhibited greater morphological adaptation to flooding than did Eucalyptus globulus or Pinus halepensis seedlings. Formation of hypertrophied lenticels and production of adventitious roots on submerged portions of stems were characteristic of the flood-tolerant species only. Ethylene production was greatly stimulated by the flooding of all species except P. halepensis. In flooded F. pennsylvanica seedlings ethylene production was higher in stems with well-developed hypertrophy than in those without stem hypertrophy. Lack of a vertical gradient in ethylene content of the stems of flooded Eucalyptus plants indicated either that waterlogging of soil indirectly stimulated ethylene production in stems above the waterline or that ethylene was translocated upward from submerged portions of stems. Application of indoleacetic acid stimulated ethylene producton in submerged portions of M. quinquenervia and U. americana stems. The data indicate an important role for ethylene in the morphological adaptation of woody plants to flooding. The additional involvement of several other compounds in such adaptation is discussed.


2019 ◽  
pp. 55-70
Author(s):  
И.Р. Грибуст

Введение. Лесомелиоративное обустройство территорий малолесных регионов коренным образом преобразует ранее пустынные пространства. Позитивные изменения влажностнотеплового, почвенного, гидрологического режимов, обогащение аборигенной дендрофлоры новыми видами влечет за собой также и трансформацию животного мира, в том числе населения насекомых. Энтомосообщества формируются за счет представителей степной группы, обитателей естественных ценозов, а также группы лесных насекомых, в числе которых виды, являющиеся опасными вредителями и их энтомофаги. Цель работы анализ изменения разнообразия насекомыхэнтомофагов в насаждениях засушливой зоны различных параметров и состояния. Объекты исследований насекомыеэнтомофаги, обитающие в энтомокомплексах защитных насаждениях различного дендрологического состава ФНЦ агроэкологии РАН на территории Волгоградской области (кадастр. 34:34:000000:122 34:08:000000:6). Материалы и методика. Сбор материала проводили в насаждениях различного хозяйственного значения. Объектами исследования являлись полезные насекомые. Отбор проб проводили посредством окашивания крон энтомологическим сачком, визуальным осмотром модельных ветвей и ручным сбором хищников и паразитированных видов филлофагов с последующим выведением имаго в лабораторных условиях. Результаты и обсуждение. В сообществе полезных насекомых защитных лесных насаждений сухостепной зоны зафиксирован 221 вид энтомофагов, относящихся к 7 отрядам и 32 семействам. Различия экологических условий, ассортимент древесных растений в каждой из посадок, характер и интенсивность негативного внешнего влияния определяют особенности фаунистического населения, в т. ч. энтомофагов. Оценка распределения количественного обилия паразитов и хищников показала, что в лесных полосах хищников в среднем в три раза больше паразитических насекомых. Отчетливо прослеживаются вариации изменения разнообразия энтомофагов в насаждениях разного класса жизнеспособности. Конструктивные особенности, флористическая обедненность и сформировавшийся микроклимат существенно ограничивает жизнедеятельность энтомофагов в малорядных (23 ряда) насаждениях, численность которых здесь снижается в среднем в 2,5 раза по сравнению с многорядными посадками. В вертикальном градиенте посадок по мощности накопления биотического потенциала полезных насекомых выделяется травянистый ярус, наличие которого в лесополосе обусловливает увеличение числа особей энтомофагов в сообществе в 1,32,7 раза. Наименьшую роль в накоплении полезной группы насекомых играет наличие развитого подлеска. Заключение. Наличие в насаждениях энтомофильных древесных растений и развитого травостоя важнейшие экологические факторы для накопления биотического потенциала энтомофагов. Максимальный эффект обеспечивает совокупное влияние определяющих экологоструктурных элементов в многорядных посадках. Introduction. Forest reclamation area developmentpoor regions is radically transforms the previously desolate space. Positive changes in moistureheat, soil, hydrological regimes, enrichment of native dendroflora with new species also entails the transformation of the animal world, including the insect population. Entomologiste formed by the representatives of the steppe group of the inhabitants of the natural coenoses, and the group of forest insects, including species that are dangerous pests and their entomophages. The purpose of the analysis of changes in the diversity of insect entomophages in the plantations of the arid zone of different parameters and conditions. The objects of research insectsentomophages living in entomocomplexes protective plantation of different dendrological composition of the Federal scientific center for Agroecology wounds on the territory of the Volgograd region (the cadaster number is 34:34:000000:122 34:08:000000:6). Materials and methods. Collection of material was carried out in plantations of various economic importance. The objects of study were useful insects. Samples were collected by hilling crowns entomological net, by visual inspection of the model branches and handcollection of predators and parasitism species of phyllophagous with subsequent excretion of adults in the laboratory. Results and discussion. 221 species of entomophages belonging to 7 groups and 32 families were recorded in the community of useful insects of protective forest plantations of the dry steppe zone. Differences in environmental conditions, the range of woody plants in each of the plantings, the nature and intensity of the negative external influence determine the characteristics of the faunal population, including entomophages The estimation of distribution of quantitative abundance of parasites and predators showed that in forest bands of predators on average three times more parasitic insects. Variations in the diversity of entomophages in plantings of different classes of viability are clearly observed. Design features, floristic depletion and formed microclimate significantly limits the life activity of entomophages in smallrow (23 rows) plantations, the number of which is reduced by an average of 2.5 times compared to multirow planting. In the vertical gradient of plantings on the power of accumulation of biotic potential of useful insects, a grassy tier is allocated, the presence of which in the forest belt causes an increase in the number of entomophages in the community by 1.32.7 times. The least role in the accumulation of a useful group of insects is played by the presence of developed undergrowth. Conclusion. The presence of entomophilic woody plants and developed herbage in the plantations are the most important environmental factors for the accumulation of the entomophage biotic potential. The maximum effect provides a cumulative effect of determining ecological and structural elements in multirow landings.



1998 ◽  
Vol 76 (8) ◽  
pp. 1366-1373 ◽  
Author(s):  
J Llusià ◽  
J Peñuelas

Terpene concentration and emission were studied in potted plants of some of the most common Mediterranean woody species (Pinus halepensis L., Pistacia lentiscus L., Cistus albidus L., Cistus monspeliensis L., Quercus ilex L., Quercus coccifera L., Phillyrea latifolia L., Phillyrea angustifolia L., and Arbutus unedo L.) under irrigation and under severe drought conditions that dropped relative water content to a range between 40% in Q. ilex and 85% in Phillyrea latifolia after withholding watering for one dry summer week. Terpene concentrations were detected in Pinus halepensis, Pistacia lentiscus, C. albidus, and C. monspeliensis, and they increased after withholding watering except in C. albidus. Terpene emission was detected in all species except Phillyrea angustifolia and A. unedo. Pinus halepensis showed the highest diurnal terpene emission rates of 86 µg·g-1 dry wt.·h-1 followed by C. albidus, Pistacia lentiscus, Q. ilex, Q. coccifera, Phillyrea latifolia, and C. monspeliensis (4 µg·g-1 dry wt.·h-1). Emitted terpenes represented from 0.33% of C fixed in C. monspeliensis to 10% in C. albidus. All species severely decreased their terpene emission rates under severe drought conditions. Emission by terpene-storing species (e.g., Pinus halepensis) was more related to temperature than in nonstoring species (e.g., Q. ilex), which showed emission relationships with photosynthetic rates. The monoterpenes alpha-pinene, beta-pinene, beta-phellandrene, and limonene and the sesquiterpene caryophyllene were the most abundant terpenes stored and emitted by these Mediterranean plant species.Key words: drought, Mediterranean conditions, terpene concentration, terpene emission, woody plants.



2013 ◽  
Vol 39 (5) ◽  
Author(s):  
Adrianna Szczepaniec ◽  
Brian Raupp ◽  
Michael Raupp

Neonicotinoid insecticides are a relatively new class of compounds with excellent efficacy against a broad assemblage of key insect pests of woody plants. Unfortunately, the use of one neonicotinoid, imidacloprid, has been linked to secondary outbreaks of several species of spider mites on different trees and shrubs. Dinotefuran is another neonicotinoid insecticide now widely used by arborists to manage insects, including egregious borers like emerald ash borer. Researchers tested a hypothesis that applications of dinotefuran to American elms (Ulmus americana) elevated populations of a spider mite, Tetranychus schoenei, and rust mites in the family Diptilomiopidae, and found no indication that dinotefuran elevated densities of either mite. Applications of imidacloprid elevated densities of T. schoenei, but not Diptilomiopidae. Both neonicotinoids were highly efficacious in reducing abundances of European elm scale, Eriococcus spuria, and elm cockscomb gall aphid, Colopha ulmicola.



1974 ◽  
Vol 52 (12) ◽  
pp. 2591-2597 ◽  
Author(s):  
Michèle C. Heath

An investigation of the changes in chloroplast ultrastructure induced by rust infection of cowpea leaves revealed that although initial changes in the pustule center resembled those observed in naturally senescing leaves, subsequent changes more closely resembled chromoplast development in certain ripening fruit. Ethylene treatment of healthy leaves induced changes similar to those seen during the later stages of pathogenesis and detached infected leaves released greater amounts of this gas than controls. The restriction of the chromoplast-like changes to the pustule center and the fact that the endogenous ethylene levels of newly picked infected leaves were barely higher than those of comparable healthy tissue suggested that most of the increased production of this gas was associated with the relatively small region of high fungal concentration. In contrast, naturally senescing leaves contained one-sixth, or less, of the ethylene content of infected leaves and released about half as much as infected tissue when detached. Thus it is suggested that, in many plants, increased ethylene production results in chromoplast-like development of the chloroplasts and that the degree of such development during pathogenesis or senescence may reflect the degree of ethylene production during these processes.



1985 ◽  
Vol 63 (3) ◽  
pp. 647-655 ◽  
Author(s):  
William J. Barnes

The woody plant population on a small, frequently flooded, river island was studied. The island occurs on the Chippewa River near Eau Claire, Wisconsin, U.S.A. The major species included sandbar willow (Salix interior, Rowlee), a small shrub; Cottonwood (Populus deltoides Marsh.) and river birch (Betula nigra L.), both early successional species in river bottoms; and silver maple (Acer saccharinum L.), green ash (Fraxinus pennsylvanica Marsh), and American elm (Ulmus americana L.) which are later successional species. Seedling input is sporadic and unpredictable. However, mortality rates of successfully established plants are quite low because of their ability to sprout following damage. The resultant clones may exhibit differing growth patterns. Willow extends laterally into adjacent unoccupied areas, thereby increasing its cover. It tends to be most abundant in the low, frequently flooded parts of the island and is predicted to continue to increase in abundance. Others, such as elm and silver maple, produce fewer sprouts which grow directly from the root crown and attain greater heights but do not spread into new areas. These species occur at higher elevations and are also predicted to increase in numbers. Still other species, such as green ash and Cottonwood, are so severely damaged by recurring beaver cutting that their normal growth form is greatly modified and their future uncertain.





ISRN Botany ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Alexander Staunch ◽  
Marie Redlecki ◽  
Jessica Wooten ◽  
Jonathan Sleeper ◽  
Jonathan Titus

To assess germination success in different microsites of a forested wetland environment, seeds of three common western New York wetland tree species, Acer x freemanii, Fraxinus pennsylvanica, and Ulmus americana, were sown into flats in the greenhouse with three substrates (mosses Hypnum imponens or Thuidium delicatulum or bare soil) and three hydrological conditions (wet, moist, or dry) in a factorial design. For the three species both treatment regimes and the interaction were highly significant, except for Acer, in which the substrate regime was not significant. Fraxinus germination had the highest tolerance for wet conditions and lowest for dry conditions followed by Acer and then Ulmus. Significant interactions showed that the effect of hydrological regime on germination is influenced by substrate type. Moss decreased germination under drier conditions and increased germination under wet conditions by lifting the seeds away from the soil and creating drier conditions than on bare soil. It is also possible that interspecific competition for moisture played a role in decreasing germination under dry conditions. By influencing the regeneration niche for three major tree species of swamps in the northeastern United States, the bryophyte layer plays an important role in determining community composition.



BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7598-7614
Author(s):  
Khaled T. S. Hassan ◽  
El-Sayed A. E. Kandeel ◽  
Ibrahim E. A. Kherallah ◽  
Hosny A. Abou-Gazia ◽  
Fatma M. M. Hassan

The utilization of branchwood as lignocellulosic raw material source for paper production may have the potential of solving the problem of the availability of raw material in the pulp and paper industry. This study therefore compared the chemical composition and fiber morphological indices (according to Franklin’s method) of stemwood and branchwood in Eucalyptus camaldulensis and Pinus halepensis trees grown in Egypt. The statistical analysis showed a significant effect of species, wood type (stem and branchwood), and their interaction on the measured chemical constituents and fiber morphological indices at 0.05 significance level. In both genera, the stemwood exhibited a higher percentage of cellulose and hemicellulose and was lower in lignin, total extractives, and ash than those measured in branchwood. Also in both genera, the stemwood was higher in fiber length, Runkel ratio, rigidity coefficient, Muhlsteph ratio, and Luce’s shape factor, and lower in basic density and flexibility coefficient than those in branchwood. Based on the chemical analysis and the fiber morphological indices, the stemwood and branchwood of both species were suitable for paper production with various qualities. Moreover, good correlations were found in both stem and branchwood between the basic density and the fiber wall thickness and fiber lumen diameter. ln contrast, there was an independent association between the stemwood basic density and the fiber length, and this relationship in branchwood was positive for both genera.



1996 ◽  
Vol 6 (1) ◽  
pp. 21 ◽  
Author(s):  
CH Sieg ◽  
HA Wright

Throughout the range of Quercus macrocarpa, fire historically played an important role in maintaining Quercus stands. However, little is known about the role of fire in maintaining stringer Quercus stands on the western edge of its distribution. This research suggests that prescribed burning could be used to rejuvenate woody plants in Quercus woodlands. Relative to unburned areas, there were more (p < 0.1) Quercus, Fraxinus pennsylvanica and Acer negundo sprouts following spring burning. However, Quercus seedling density did not increase (p = 0.22) relative to unburned sites, and changes in the density of woody understory species in response to burning were erratic. Dormant season burning has some appeal from a fire control point of view and because carbohydrate reserves in woody plants are high during this time. However, if the objective is to regenerate woody plants and/or mimic historical fires, prescriptions should be set to achieve high intensities.



1979 ◽  
Vol 57 (21) ◽  
pp. 2466-2470 ◽  
Author(s):  
T. T. Kozlowski ◽  
S. G. Pallardy

Low temperatures (3–10 °C) for 1 h to 6 days increased leaf diffusion resistance (r1) of Ulmus americana and Fraxinus pennsylvanica seedlings, indicating rapid stomatal closure. The change in r1 increased as the temperature was lowered over a range of 10–3 °C. After cessation of cold-stress treatment, r1 values recovered within 1 day to prestress levels. No significant differences were found in speed of recovery of r1 in plants after exposure to cold over a range of 3– 10 °C. Stomatal closure could account thus for at least part of the decrease in photosynthesis at low temperatures.



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