scholarly journals Invazivne biljne vrste i ekološki čimbenici koji utječu na njihovo širenje na području spomenika prirode „Obrenovački Zabran“ (Središnja Srbija)

2016 ◽  
Vol 140 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
Jovana Petrović ◽  
Srećko Ćurčić ◽  
Nenad Stavretović
Keyword(s):  
Asclepias Syriaca ◽  
Amorpha Fruticosa ◽  
I 18

Osnovni cilj i zadatak provedenog istraživanja bio je utvrditi prisutnost invazivnih biljnih vrsta na području zaštićenog prirodnog dobra Spomenik prirode „Obrenovački Zabran“ (središnja Srbija). Istraživanja flore i vegetacije šume Obrenovački Zabran rađena su tijekom više vegetacijskih sezona od ožujka 2009. do studenog 2013. godine. Bogatstvo flore ogleda se kroz prisutnost 163 biljne vrste koje su zabilježene na području Obrenovačkog Zabrana. Od ukupnog broja zabilježenih biljnih vrsta, 24 taksona su označena kao invazivne vrste, što čini 14,72% ukupne flore Zabranske šume. Među njima je prisutno 6 drvenastih i 18 zeljastih biljnih vrsta. Duž čitavog nasipa u Obrenovačkom Zabranu evidentirane su vrste Asclepias syriaca i Amorpha fruticosa s velikom pokrovnošću i brojnošću. Ove dvije vrste formiraju rub šume ka rijeci Savi, tako da su potisnule gotovo sve druge biljne vrste iz kata žbunja, s tendencijom da potisnu i već sada oskudnu prizemnu vegetaciju. Svjetlost i temperatura su ekološki čimbenici koji posebno pogoduju razvoju i širenju invazivnih biljaka u Obrenovačkom Zabranu, a koji su najizraženiji u području nasipa. Zbog toga i zbog izraženog antropogenog utjecaja, tj. velike frekvencije korisnika, invazivne vrste biljaka su unešene i prisutne na području Zabrana. Od ukupnog broja zabilježenih invazivnih vrsta biljaka, najveći broj pripada porodici Asteraceae (9 vrsta), zatim porodicama Poaceae i Fabaceae (s po 2 vrste), dok su ostale porodice zastupljene sa po jednom vrstom. Rezultati istraživanja trebaju dati osnovu za razvoj strategije za praćenje stanja i planiranje mjera za suzbijanje neželjenih biljnih vrsta radi zaštite autohtone flore. Samo pažljivo i odgovorno upravljanje prirodnim dobrom omogućit će da se broj invazivnih biljnih vrsta održi na postojećoj razini.

UPAYA MENINGKATKAN HASIL BELAJAR MENGGAMBAR BUAH-BUAHAN DENGAN MENGGUNAKAN METODE DEMONSTRASI DI KELAS VII SMP IT AL-FITYAN SCHOOL MEDAN

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
DIAN LESTARI
Keyword(s):  
I 18

Penelitian tindakan kelas ini dilakukan di SMP IT Al-Fityan School Medan. Dari hasil wawancara dengan guru seni budaya ditemukan bahwa para siswa belum pernah diajarkan menggambar bentuk buah-buahan secara langsung, belum pernah mendapatkan pengalaman belajar dari lingkungan mereka sendiri dan hasil belajar siswa dalam pelajaran Seni Budaya dan Keterampilan masih kurang. Tujuan penelitian ini adalah dengan metode demonstrasi dapat meningkatkan hasil belajar menggambar buah-buahan siswa kelas VII-B SMP IT Al-Fityan School Medan. Penelitian ini menggunakan pendekatan Penelitian Tindakan Kelas (PTK) dengan 2 siklus. Subyek penelitian ini adalah siswa kelas VII-B SMP IT Al-Fityan School Medan dengan jumlah 31 siswa. Setiap siklus terdiri dari Perencanaan, Pelaksanaan, Pengamatan/Observasi, dan Refleksi. Instrumen penelitian yang digunakan adalah Lembar Penilaian Siswa, Tes Unjuk Kerja, Wawancara, Catatan Lapangan dan dokumentasi. Hasil-hasil penelitian yang diperoleh adalah hasil belajar pada tiap siklus terjadi peningkatan, yaitu nilai rata-rata kelas Siklus I mencapai 73,18 dengan siswa yang tuntas belajar 14 siswa atau 45,16%. Siklus II nilai rata-rata kelas mencapai 83,91, siswa yang mengalami tuntas belajar sebanyak 27 siswa atau 87,10%. Aspek ketepatan bentuk pada siklus I 18 siswa (58,07%) yang tuntas, pada siklus II mengalami peningkatan menjadi 27 siswa (87,09%) yang tuntas. Aspek gelap terang pada siklus I 12 siswa (38,70%) yang tuntas, pada silkus II mengalami peningkatan menjadi 28 siswa (90,32%) yang tuntas. Aspek arsiran pada siklus I 12 siswa (38,70%) yang tuntas, pada silkus II mengalami peningkatan menjadi 27 siswa (87,09%) yang tuntas.Aspek komposisi pada siklus I 20 siswa (64,52%) yang tuntas, pada silkus II mengalami peningkatan menjadi 29 siswa (93,54%) yang tuntas.Aspek proporsi pada siklus I 19 siswa (61,30%) yang tuntas, pada silkus II mengalami peningkatan menjadi 29 siswa (93,54%) yang tuntas. Kata Kunci: Hasil belajar, menggambar buah-buahan, metode demonstrasi.

THE ROLE OF INSECTS IN THE SPREAD OF CUCUMBER MOSAIC VIRUS

1964 ◽  
Vol 44 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. J. McClanahan ◽  
G. E. Guyer
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Small Proportion ◽  
Aphis Gossypii ◽  
Macrosiphum Euphorbiae ◽  
Asclepias Syriaca ◽  
Melanoplus Differentialis ◽  
Aphis Gossypii Glover ◽  
Echinocystis Lobata

Entomological aspects of the epidemiology of cucumber mosaic virus (CMV) were studied in Michigan. Myzus persicae (Sulzer) and Aphis gossypii Glover were efficient vectors of CMV between various hosts in the laboratory. Macrosiphum euphorbiae (Thomas) transmitted CMV between cucumber and Echinocystis lobata (Michx.) T. & G. Myzocallis asclepiadis (Monell) was shown to be a new vector of CMV between Asclepias syriaca L. Neither Melanoplus differentialis (Thomas) nor Acalymma vittata (Fabricius) transmitted the virus in limited trials.There was a small proportion of cucumber plants infected early in July, when alate M. persicae were present. In August the incidence of infection rose rapidly after a period of activity of alate A. gossypii. Alate aphids were trapped in yellow water pans situated in and around cucumbers. Seven known vectors of CMV were caught.

ChemInform Abstract: CARDENOLIDES OF ASCLEPIAS SYRIACA L., PROBABLE STRUCTURE OF SYRIOSIDE AND SYRIOBIOSIDE

1979 ◽  
Vol 10 (22) ◽  
Author(s):  
P. BROWN ◽  
J. VON EUW ◽  
T. REICHSTEIN ◽  
K. STOECKEL ◽  
T. R. WATSON
Keyword(s):  
Probable Structure ◽  
Asclepias Syriaca

scholarly journals Aging effect on nectar production in two clones of Asclepias syriaca

Oecologia ◽  
1983 ◽  
Vol 56 (1) ◽  
pp. 121-125 ◽  
Author(s):  
A. K. Southwick ◽  
E. E. Southwick
Keyword(s):  
Aging Effect ◽  
Asclepias Syriaca ◽  
Nectar Production

ON DISTRTBUTION PATTERN OF AMORPHA FRUTICOSA L. IN THE REGION OF KANEVSKAYA HYDROPOWER STATION (UKRAINE) IN CONNECTION WITH HYDROCHORY

2021 ◽  
Vol 14 (1) ◽  
pp. 107-115
Author(s):  
T. V. Shevchik ◽  
T. S. Dvirna ◽  
V. L. Shevchik
Keyword(s):  
Water Surface ◽  
Water Yield ◽  
Surface Level ◽  
Amorpha Fruticosa ◽  
Active Dispersal ◽  
Active Dissemination ◽  
Maximum Water ◽  
Hydropower Stations ◽  
Determining Factor ◽  
Natural Way

Amorpha fruticosa L. is a kenophyte of North American origin, ergaziophyte. Currently, this species naturalized over large areas and became the background on the coast waters of the Dnieper reservoirs of hydropower stations. It is necessary to clarify the reasons for the distribution of A. fruticosa populations in different parts of the Middle Dnieper coast under conditions of artificial regulation of its water yield. It has been proven that the high buoyancy of A. fruticosa fruits provides the possibility of its active dispersal along river beds in a natural way under conditions of fluctuations in the level of surface water yield right in spring floods. The main and determining factor in the active dissemination of the species on the coast of the Kanev and Kremenchug reservoirs is the frequent variability of the maximum water surface level. The narrow altitudinal range of distribution of this species on the coast in the lower parts, and accordingly, wider in the upper parts of the reservoirs is determined by the corresponding indicators of water level differences. The possibility of artificial regulation of the water surface level with knowledge of the characteristics of hydrochory of this invasive species makes it possible to influence its distribution in the territory near the reservoirs.

The influence of fire on Spartina pectinata wetland communities in a northeastern Kansas tallgrass prairie

1995 ◽  
Vol 73 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Stephen R. Johnson ◽  
Alan K. Knapp
Keyword(s):  
Tallgrass Prairie ◽  
Light Availability ◽  
Fire Frequency ◽  
Plant Species Composition ◽  
Prairie Wetlands ◽  
Asclepias Syriaca ◽  
Spartina Pectinata ◽  
Galium Aparine ◽  
Reduced Light ◽  
Diverse Plant

Wetlands dominated by the C4 grass Spartina pectinata were investigated to quantify differences in plant species composition and diversity in response to fire frequency. The study site was a tallgrass prairie in northeastern Kansas that included Spartina wetlands subjected to spring fires at 1-, 2-, 4-, 10-, and 20-year intervals. Because C3 forbs in these wetlands responded strongly to different fire frequencies, the light environment and gas exchange responses of the ubiquitous forb Asclepias syriaca were also assessed. In general, species diversity was lower in annually burned wetlands because of lower forb diversity. Maximum H′ in annually burned sites was 1.64 versus 2.77 in 10- and 20-year burned sites. However, individual forb responses varied. Asclepias increased and Solidago canadensis and Galium aparine decreased in importance with increasing fire frequency. Canopy sunlight interception was greater in annually burned wetlands than in wetlands with lower burn frequencies. Despite reduced light availability, midseason photosynthetic rates of Asclepias were higher in annually burned sites. The results suggest that frequent fire in tallgrass prairie wetlands results in less diverse plant communities, similar to responses of upland prairie, and that the timing of fire, relative to life history and phenology of the subordinate species, strongly influences responses of individual forbs. Key words: wetlands, tallgrass prairie, Spartina pectinata communities, fire.

Structure and stereochemistry of amorphispironone, a novel cytotoxic spironone type rotenoid from Amorpha fruticosa

1991 ◽  
pp. 1652 ◽  
Author(s):  
Leping Li ◽  
Hui-Kang Wang ◽  
Toshihiro Fujioka ◽  
Jer-Jang Chang ◽  
Mutsuo Kozuka ◽  
...  
Keyword(s):  
Amorpha Fruticosa

scholarly journals Induced defenses alter the strength and direction of natural selection on reproductive traits in common milkweed

2016 ◽  
Author(s):  
Ken A. Thompson ◽  
Kaitlin A. Cory ◽  
Marc T. J. Johnson
Keyword(s):  
Natural Selection ◽  
Jasmonic Acid ◽  
Reproductive Traits ◽  
Induced Defenses ◽  
Asclepias Syriaca ◽  
Ecological Processes ◽  
Foliar Damage ◽  
Antiherbivore Defenses ◽  
Selection For ◽  
Generate Plant

AbstractEvolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defenses can alter natural selection on reproductive traits, but it is unclear whether induced defenses will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca, we induced plant defenses using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), while control plants only experienced a trend toward selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defenses can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defenses may promote the evolution of plant reproductive diversity.

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