1 / 48

Department of Forest Science, OSU Fen-Hui Chen 陳芬蕙 November 18, 2003

Effects of Weed Control on Plant Species Diversity in Douglas-fir and Other Pacific Northwest Conifer Plantations. Department of Forest Science, OSU Fen-Hui Chen 陳芬蕙 November 18, 2003. Questions.

xia
Download Presentation

Department of Forest Science, OSU Fen-Hui Chen 陳芬蕙 November 18, 2003

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Effects of Weed Control on Plant Species Diversity in Douglas-fir and Other Pacific Northwest Conifer Plantations Department of Forest Science, OSU Fen-Hui Chen 陳芬蕙 November 18, 2003

  2. Questions • How does the composition of plant species change after weed control treatments? Will species diversity decrease? • What are the mechanisms of invasion among species?

  3. -- VMRC Research --Critical Period Thresholds, Effects of up to five years of consecutive Weed Control relative to growth losses from delaying weed control for Douglas-fir and other PNW conifer species

  4. Four sites with four conifer species

  5. Study one– Weed control treatment T= herbicide treated, O= untreated

  6. Herbicide treatments and timing

  7. The arrangement of 36 seedlings in each plot ●: buffer tree

  8. Sweet Home Sweet Home

  9. CIVU, Bull thistle RUUR, Trailing blackberry HYRA, False dandelion GASH, Salal

  10. Seaside

  11. Starker Site

  12. Roseburg

  13. Study two – Invasion mechanism trial(Sweet Home) SEED BANK STUDY (soil seeds) SEED RAIN STUDY (dispersal seeds) BUD BANK STUDY (vegetative parts)

  14. 1. SEED BANK STUDY • Soil sample: 5 soil cores (5 cm in diameter x 5 cm deep) -April • Total sampling area: 0.051 m2/ plot • Emergent seedlings ~September • Density: seedlings/m2 • 2002, 2003

  15. 2002

  16. 2003

  17. 2002 OOOOO TTTTO

  18. 2003 OOOOO OOTTT

  19. Senicio sylvaticus (woodland groundsel) Phacelia nemoralis (woodland phacelia) Epilobium munitum (near fire weed) Cirsium culgare (bull thistle)

  20. 2. SEED RAIN STUDY 4 seed traps (34 cm x 20 cm x 10 cm Sterilite plastic box filled with 5 cm soil) - late April 2002 OSU Greenhouse- spring 2003 Total sampling area: 0.207 m2/ plot Emergent seedlings : 11. 2002~ 9. 2003 Density: seedlings/m2

  21. 3. BUD BANK STUDY • 4 bud bank assessment subplots (1 m x 1 m) • Individuals – June and August • Total sampling area: 4 m2/ plot • Density: individual /m2 • 2002, 2003

  22. CIAR, Canadian thistle EPAN, Fireweed TRLA, Star flower

  23. Thank you ! Sweet Home

More Related