نتایج جستجو برای: herbaceous distillates

تعداد نتایج: 4501  

2015
James L. Hanula Scott Horn Joseph J. O’Brien

Two conservation goals of the early 20th century, extensive reforestation and reduced wildfire through fire exclusion, may have contributed to declining pollinator abundance as forests became denser and shrub covered. To examine how forest structure affects bees we selected 5 stands in each of 7 forest types including: cleared forest; dense young pines; thinned young pines; mature open pine wit...

Journal: :Remote Sensing 2016
Abdoul Aziz Diouf Pierre Hiernaux Martin Brandt Gayane Faye Bakary Djaby Mouhamadou Bamba Diop Jacques André Ndione Bernard Tychon

Quantitative estimates of forage availability at the end of the growing season in rangelands are helpful for pastoral livestock managers and for local, national and regional stakeholders in natural resource management. For this reason, remote sensing data such as the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) have been widely used to assess Sahelian plant productivity for ...

Journal: :Annals of botany 2012
Frederic Lens Sharon Eeckhout Rosa Zwartjes Erik Smets Steven B Janssens

BACKGROUND AND AIMS The family Balsaminaceae is essentially herbaceous, except for some woodier species that can be described as 'woody' herbs or small shrubs. The family is nested within the so-called balsaminoid clade of Ericales, including the exclusively woody families Tetrameristaceae and Marcgraviaceae, which is sister to the remaining families of the predominantly woody order. A molecula...

Journal: :Journal of the American Mosquito Control Association 1991
N S Tietze P G Hester C F Hallmon M A Olson K R Shaffer

Toxicity of Florida mosquito larvicides and adulticides to 3-5 day old Gambusia affinis was determined in the laboratory. After 24-h exposure, the larvicides, temephos, fenoxycarb and petroleum distillates had LC50 values of 5.60, 1.05 and 593.4 ppm, respectively. After 24 h the adulticides resmethrin, fenthion, naled and malathion had LC50 values of 0.007, 2.94, 3.50 and 12.68 ppm, respectivel...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1996
U R Böhle H H Hilger W F Martin

Numerous island-inhabiting species of predominantly herbaceous angiosperm genera are woody shrubs or trees. Such "insular woodiness" is strongly manifested in the genus Echium, in which the continental species of circummediterranean distribution are herbaceous, whereas endemic species of islands along the Atlantic coast of north Africa are woody perennial shrubs. The history of 37 Echium specie...

1996
MICHAEL D. CAIN

Four levels of vegetative competition wete used to quantify the growth of loblolly and shot-deaf pines (Pinus taeda L. and /? echinatu Mill.) in naturally regenerated, even-aged stands on the Upper Coastal Plain of southeastern Arkansas, USA. Treatments included: (I) no competition control, (2) woody competition control, (3) herbaceous competition control. and (4) total control of nonpine veget...

2012
William E. Rogers Elizabeth A. McMahon Bryce R. Thomas Urs P. Kreuter Terry L. Blankenship

Widely-held, untested assumptions in many prairies are that high-intensity fires conducted during droughts will decrease native herbaceous species richness and lead to rapid invasions by alien species. We compared native and exotic herbaceous species richness and aboveground herbaceous biomass one year following the application of highintensity growing-season fires in Texas coastal prairie. Fir...

Journal: :Journal of environmental biology 2007
Murat Demir E Makineci E Yilmaz

In this study the impact of production work on the skid roads that have been carried out for many years by manpower animal power or machinery in a beech (Fagus orientalis Lipsky) stand have been examined. For this purpose, herbaceous understory, forest floor and soil samples were collected from the undisturbed area and the skid road. Weight per unit area (kg ha(-1)), organic matter ratio and mo...

2012
Rina Kamenetsky John Dole

Peony (Paeonia spp.) is one of the most popular garden plants in temperate regions. They were introduced into cultivation in China hundreds of years ago, and have since been spread widely to many countries. According to morphological traits and life form, the genus is divided into tree and herbaceous peonies. Numerous cultivars of herbaceous peonies have been developed to satisfy demand for col...

2015
Amartuvshin Narantsetseg Sinkyu Kang Dongwook Ko

Wells in grasslands are usually accompanied with increased traffic by humans and livestock. The purpose of this study was to detect whether plant community structure differs in spatial arrangement with different grazing gradients in the desert steppe of Mongolia. We found poor correlation between total coverage and distance-to-well in bigshrub and shrub-limited sites but strong correlation in t...

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