juniperus virginiana
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Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 101
Author(s):  
Brice B. Hanberry

Eastern redcedar (Juniperus virginiana L.) is increasing in density in the eastern United States and expanding in range to the west, while western Juniperus species also are increasing and expanding, creating the potential for a novel assemblage. I estimated range expansion and intersection by comparing recent USDA Forest Service Forest Inventory and Analysis surveys (mean year = 2009) to the oldest available surveys (mean year = 1981), with adjustments for sampling changes, and predicted climate envelopes during the following year ranges: 1500–1599, 1800–1849, 1850–1899, 1900–1949, and 1960–1989. During approximately 28 years, eastern redcedar range expanded by about 54 million ha (based on ≥0.5% of total stems ≥12.7 cm in diameter in ecological subsections). Combined range of western species of juniper did not expand. Range intersection of eastern redcedar and western Juniperus species totaled 200,000 km2 and increased by 31,600 km2 over time, representing a novel assemblage of eastern and western species. Predicted ranges during the other time intervals were 94% to 98% of predicted area during 1960–1989, suggesting major climate conditions have been suitable for centuries. The southern western Juniperus species and Rocky Mountain juniper (Juniperus scopulorum Sarg.) have the greatest potential for intersection with eastern redcedar, whereas eastern redcedar may have concluded westward expansion.


2021 ◽  
Vol 20 (6) ◽  
pp. 19-29
Author(s):  
Małgorzata Schollenberger ◽  
Agnieszka Gadomska-Gajadhur ◽  
Ewa Mirzwa-Mróz ◽  
Damian Kret ◽  
Ewa Skutnik ◽  
...  

 The activity of essential oils from Eucalyptus globulus, Pinus silvestris, Lavandula angustifolia, Juniperus virginiana, Rosmarinus officinalis and Citrus paradise against the soft-rot pathogens Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri and Dickeya solani was determined in vitro. The antibacterial activity of the essential oils will be evaluated using the disk-diffusion method by Kirby-Bauer [Bauer et al. 1966]. It was found that all the presented essential oils varied in antimicrobial activity against the four bacterial strains. No differences in the influence of streptomycin on inhibition of growth of the four bacterial strains were observed. Among six tested plants, essential oils from P. sylvestris had the strongest inhibitory effect on the growth of soft rot bacteria from Pectobacterium genus. This paper constitute the first report on the activity of the essential oils obtained from J. virginiana against soft rot bacteria. They are also the first report on the activity of the essential oils obtained from E. globulus, P. silvestris, L. angustifolia and C. paradisi against P. atrosepticum, P. parmentieri and D. solani as well as on the activity of the R. officinalis essential oils against P. atrosepticum and P. parmentieri.


2021 ◽  
Vol 131 ◽  
pp. 108159
Author(s):  
Anastasios Mazis ◽  
Julie A. Fowler ◽  
Jeremy Hiller ◽  
Yuzhen Zhou ◽  
Brian D. Wardlow ◽  
...  

2021 ◽  
pp. 4-34
Author(s):  
А.В. Семенютина ◽  
М.В. Цой

Актуальность связана с расширением зеленого строительства на новых территориях в разнообразных и нередко тяжелых природных и агротехнических условиях возникла потребность в широком и разнообразном по биологическим и техническим свойствам ассортименте древесных пород и разработке дифференцированных методов их выращивания. Интродукция должна быть основана на обстоятельном изучении существующего опыта интродукции и знании стран – источников интродукции, истории формирования того или иного вида, учета экологических особенностей местообитаний, вертикальной зональности, существования географических и эдафических форм. Цель исследования заключалась в изучении эколого-биологических особенностей таксонов семейства Cupressaceae Bartl. в дендрологических коллекциях сухостепного региона. Исследованы шесть древесных вида семейства Cupressaceae, произрастающие в дендроколлекциях ФНЦ Агроэкологии РАН: Juniperus virginiana L., J. communis L., J. sabina L., Thuja occidentalis L, Platycladus orientalis(L.) Franco, Pseudotsuga menziesii (Milb) Franco. Изучены естественные ареалы объектов исследования. Выявлено, что виды подсемейства Thujoideae встречаются как в северном, так и в южном полушарии, виды подсемейства Juniperoideae (род Juniperus) – в умеренных областях северного полушария. Фенологические наблюдения выявили, что рост хвои у можжевельника обыкновенного начинался одновременно с ростом побегов в конце марта - начале апреля (на 1-1,5 месяца раньше, чем на родине), Период роста хвои продолжался 2-2,5 месяца, побегов – 135-180 дней. В ходе наблюдений за динамикой роста сеянцев, были получены метрические показатели сеянцев, 1-летние сеянцы Platycladus orientalis – 16-18 см, Thuja occidentalis – 9-14 см, J. communis – 10-15 см, J. sabina – 14-16 см, Juniperus virginiana – 14-16 см высотой. Анализ изменчивости морфологических признаков и биоэкологических свойств, адаптаций в новых условиях среды имеют большое значение для биоэкологического обоснования введения в культуру древесных таксонов семейства Cupressaceae. Этот анализ затрагивает оценку природного разнообразия растений с таких важных сторон, как скорость роста, устойчивость и декоративность, сведений о которых в засушливых условиях крайне мало. The urgency is connected with the expansion of green construction in new territories in diverse and often difficult natural and agrotechnical conditions, there is a need for a wide and diverse assortment of tree species in terms of biological and technical properties and the development of differentiated methods of their cultivation. The introduction should be based on a thorough study of the existing experience of introduction and knowledge of the countries - sources of introduction, the history of the formation of a particular species, taking into account the ecological features of habitats, vertical zonality, the existence of geographical and edaphic forms. The aim of the study was to study the ecological and biological features of the taxa of the Cupressaceae Bartl family. in dendrological collections of the dry-steppe region. Six woody species of the Cupressaceae family growing in the arboretum collections of the Federal Research Center of Agroecology of the Russian Academy of Sciences were studied: Juniperus virginiana L., J. communis L., J. sabina L., Thuja occidentalis L, Platycladus orientalis (L.) Franco, Pseudotsuga menziesii (Milb) Franco. The natural areas of the objects of study have been studied. It was revealed that the species of the subfamily Thujoideae are found in both the northern and southern hemispheres, the species of the subfamily Juniperoideae (genus Juniperus) – in the temperate regions of the northern hemisphere. Phenological observations revealed that the growth of needles in common juniper began simultaneously with the growth of shoots in late March - early April (1-1.5 months earlier than at home), the period of growth of needles lasted 2-2.5 months, shoots - 135-180 days. During observations of the growth dynamics of seedlings, metric indicators of seedlings were obtained, 1-year-old seedlings Platycladus orientalis - 16-18 cm, Thuja occidentalis - 9-14 cm, J. communis - 10-15 cm, J. sabina - 14-16 cm, Juniperus virginiana - 14-16 cm tall. Analysis of the variability of morphological features and bioecological properties, adaptations in new environmental conditions are of great importance for the bioecological justification of the introduction of woody taxa of the Cupressaceae family into culture. This analysis affects the assessment of the natural diversity of plants from such important aspects as growth rate, stability and decorative properties, information about which is extremely scarce in arid conditions.


Author(s):  
Caleb Aldridge ◽  
David M Norris ◽  
Hunter R Hatcher ◽  
Giancarlo Coppola ◽  
Leandro E Miranda ◽  
...  

Brush piles (i.e., trees and large woody debris) are often installed in reservoirs to supplement fish habitat. The retention and dimensional change of brush piles after installation is important information that can be used to maximize the effectiveness of this management action. We evaluated the retention and dimensional change of 70 eastern red cedar Juniperus virginiana and bald cypress Taxodium distichum brush piles in an embayment of a drawdown reservoir up to four annual cycles of submergence and exposure. We used satellite imagery to supplement our onsite measurements of retention. We also examined spatial patterns of brush pile retention and dimensional change. Brush piles were lost at 10% per year and their volume at 14% per year. We compared our rates of brush pile retention and dimensional change with those from a holdout data set of 50 brush piles. Estimates between data sets did not differ statistically. Spatial patterns of retention and dimensional change coincided with morphological features in our study area, suggesting that retention and dimensional change is influenced by variable physical forces (e.g., wave action and flow) at installation locations. Our estimates of brush pile retention and dimensional change can be used to generally sustain desirable brush densities. For example, to maintain a fixed total volume of brush in our study embayment roughly 23% of the total brush volume installed would need to be replaced annually. Similar research in reservoirs managed for other purposes is needed as length and cycle of inundation could lead to variable rates of retention and dimensional change. Additionally, advancements into computer-assisted detection and volume estimation could reduce the time and effort needed to monitor brush piles.


2021 ◽  
Author(s):  
Samia Hamati ◽  
Juliana S. Medeiros ◽  
David Ward

Abstract Water availability may alter species competitive interactions, resulting in different outcomes as plants compete for available water. Eastern redcedar Juniperus virginiana (hereafter ERC) will likely continue to encroach into new habitats, which will affect soil and water budgets. We designed a greenhouse experiment to investigate changes in water uptake and rooting depths of two-year old ERC saplings in the presence of an invasive grass (Bromus inermis) and a native tree (Quercus stellata). We measured soil moisture content over two growing seasons. When grown together, ERC took up water from the deeper layers (21–40 cm) whereas B. inermis used water from the top layers of the soil (0–20 cm). Similarly, when ERC grew with Q. stellata, ERC took up water from the deeper layers and Q. stellata used water mostly from the top layers. This root partitioning can allow the co-existence of ERC, grasses, and other trees, which can facilitate ERC encroachment into grasslands and woodlands. However, when the three species grew together, we found root overlap between the ERC and Q. stellata. This overlap can affect ERC establishment and encroachment in habitats where grasses and trees co-occur. A major factor that affected ERC performance was higher mortality in treatments with B. inermis than in the ERC-alone or with Q. stellata. This indicates that competition with grasses is a major factor affecting ERC sapling establishment.


2021 ◽  
Vol 78 ◽  
pp. 112-116
Author(s):  
Dillon T. Fogarty ◽  
Caitlin de Vries ◽  
Christine Bielski ◽  
Dirac Twidwell
Keyword(s):  

2021 ◽  
pp. 17-32
Author(s):  
А.В. Семенютина ◽  
М.В. Цой ◽  
В.В. Сапронов

В Волгоградской области единственным аборигенным представителем хвойных древесных растений является J. sabina L., существования популяции одного представителя хвойных свидетельствует об однородности дендрофлоры, что может привести к деструкции экосистемы в целом. Интродукция растений как инструмент на пути к достижению биоразнообразия дендрофлоры, является наиболее практичным и перспективным методом в условиях сухой степи. Целью исследования, являлось проведение биоэкологической оценки и жизненного состояния хвойных древесных растений, а также определение степени интродукционной устойчивости условиях сухой степи. Проведена оценка шести интродуцированных древесных растений в дендроколлекциях ФНЦ Агроэкологии РАН: Juniperus virginiana L., J. communis L., J. sabina L., Thuja occidentalis L, Platycladus orientalis(L.) Franco, Pseudotsuga menziesii (Milb) Franco. Определены сроки наступления и длительность основных фенологических фаз методикой фенологических наблюдений ГБС. При отклонении среднегодовой температуре воздуха выше нормы на 1,05 ºС и годовой суммы осадков 75% от нормы, длительность проявления периода вегетации составила у J. sabina L. – 58 дней, самый короткий период у J. communis L. – 41 день, Pseudotsuga menziesii (Milb) Franco 55 дней, J. virgiana L. – 56 дней, T. occidentalis L. – 71 день, P. orientalis (L.) Franco – 68 дней. В рамках эколого-биологической оценки были исследованы такие показатели как зимостойкость, засухоустойчивость, характер пыления и семеношения. Отдельно был исследован семенной материал методом определения массы 1000 семян. Также была дана оценка декоративности, по которой определялась специфика применения того или иного вида для целей озеленения. В результате проведенных исследований рассчитали значения акклиматизационного числа для каждого вида, по которому определена степень интродукционной устойчивости в условиях сухой степи. В ходе проделанной работы даны практические рекомендации по посадке хвойных деревьев кустарников для целей озеленения. In the Volgograd region, the only native representative of coniferous woody plants is J. sabina L., the existence of a population of one representative of coniferous plants indicates the homogeneity of the dendroflora, which can lead to the destruction of the ecosystem as a whole. Plant introduction as a tool on the way to achieving dendroflora biodiversity is the most practical and promising method in the conditions of the dry steppe. The aim of the study was to conduct a bioecological assessment of the life condition of coniferous woody plants, as well as to determine the degree of introduction resistance in the conditions of the dry steppe. Six introduced woody plants were evaluated in the dendrocollections of the Federal Research Center of Agroecology of the Russian Academy of Sciences: Juniperus virginianaL., J. communis L., J. sabina L., Thuja occidentalis L, Platycladus orientalis (L.) Franco, Pseudotsuga menziesii (Milb) Franco. The timing of the onset and duration of the main phenological phases were determined by the method of phenological observations of HBS. With the deviation of the average annual air temperature above the norm by 1.05 ° C and the annual precipitation of 75% of the norm, the duration of the vegetation period was 58 days for J. sabina L., 41 days for J. communis L., 55 days for Pseudotsuga menziesii (Milb) Franco, 56 days for J. virgiana L., 71 days for T. occidentalis L., and 68 days for P. orientalis (L.) Franco. As part of the ecological and biological assessment, such indicators as winter hardiness, drought resistance, the nature of dusting and seed-bearing were studied. Separately, the seed material was examined by the method of determining the mass of 1000 seeds. There was also an assessment of decorativeness, which determined the specifics of the use of a particular type for landscaping purposes. As a result of the conducted studies, the values of the acclimatization number for each species were calculated, according to which the degree of introduction resistance in the conditions of the dry steppe was determined. In the course of the work done, practical recommendations are given for planting coniferous trees and shrubs for landscaping purposes.


2021 ◽  
Vol 13 (10) ◽  
pp. 1975
Author(s):  
Lin Wang ◽  
Yuzhen Zhou ◽  
Qiao Hu ◽  
Zhenghong Tang ◽  
Yufeng Ge ◽  
...  

Woody plant encroachment into grasslands ecosystems causes significantly ecological destruction and economic losses. Effective and efficient management largely benefits from accurate and timely detection of encroaching species at an early development stage. Recent advances in unmanned aircraft systems (UAS) enabled easier access to ultra-high spatial resolution images at a centimeter level, together with the latest machine learning based image segmentation algorithms, making it possible to detect small-sized individuals of target species at early development stage and identify them when mixed with other species. However, few studies have investigated the optimal practical spatial resolution of early encroaching species detection. Hence, we investigated the performance of four popular semantic segmentation algorithms (decision tree, DT; random forest, RF; AlexNet; and ResNet) on a multi-species forest classification case with UAS-collected RGB images in original and down-sampled coarser spatial resolutions. The objective of this study was to explore the optimal segmentation algorithm and spatial resolution for eastern redcedar (Juniperus virginiana, ERC) early detection and its classification within a multi-species forest context. To be specific, firstly, we implemented and compared the performance of the four semantic segmentation algorithms with images in the original spatial resolution (0.694 cm). The highest overall accuracy was 0.918 achieved by ResNet with a mean interaction over union at 85.0%. Secondly, we evaluated the performance of ResNet algorithm with images in down-sampled spatial resolutions (1 cm to 5 cm with 0.5 cm interval). When applied on the down-sampled images, ERC segmentation performance decreased with decreasing spatial resolution, especially for those images coarser than 3 cm spatial resolution. The UAS together with the state-of-the-art semantic segmentation algorithms provides a promising tool for early-stage detection and localization of ERC and the development of effective management strategies for mixed-species forest management.


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