1 / 121

Nicholas J. Gotelli Department of Biology University of Vermont Burlington, VT 05405 U.S.A.

Nitrogen deposition and extinction risk in carnivorous plants: ecological challenges for the next century. Nicholas J. Gotelli Department of Biology University of Vermont Burlington, VT 05405 U.S.A. Effects of N Deposition. Individual Altered morphology

nolen
Download Presentation

Nicholas J. Gotelli Department of Biology University of Vermont Burlington, VT 05405 U.S.A.

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. Nitrogen deposition and extinction risk in carnivorous plants: ecological challenges for the next century Nicholas J. Gotelli Department of Biology University of Vermont Burlington, VT 05405 U.S.A.

  2. Effects of N Deposition • Individual • Altered morphology • Changes in reproduction, survivorship

  3. Effects of N Deposition • Individual • Altered morphology • Changes in reproduction, survivorship • Population • Increased long-term extinction risk • Changes in short-term dynamics

  4. Effects of N Deposition • Individual • Altered morphology • Changes in reproduction, survivorship • Population • Increased long-term extinction risk • Changes in short-term dynamics • Community • Changes in abundance and composition • Altered nutrient transfer and storage

  5. Effects of N Deposition on Carnivorous Plants • Life History • Effects on Individuals • Effects on Populations • Effects on Communities • The Role of Ecologists

  6. Effects of N Deposition on Carnivorous Plants • Life History • Effects on Individuals • Effects on Populations • Effects on Communities • The Role of Ecologists

  7. Carnivorous plants: well-known, but poorly studied

  8. Carnivory in plants • Phylogenetically diverse • Morphological, chemical adaptations for attracting, capturing, digesting arthropods • Common in low N habitats • Poor competitors for light, nutrients

  9. Family Sarraceniaceae

  10. Genus Sarracenia • 8 described species • Center of diversity in southeastern US • Many subvarieties • Extensive hybridization • Sarracenia purpurea (New Jersey- Canada)

  11. The Northern Pitcher Plant Sarracenia purpurea • Perennial plant of low-N peatlands • Lifespan 30-50 y • Arthropod prey capture in water-filled pitchers • Diverse inquiline community in pitchers

  12. Sarraceniopus gibsoni Wyeomyia smithii The Inquilines Blaesoxipha fletcheri Habrotrocha rosa Metriocnemus knabi

  13. Inquiline food web

  14. Phyllodia • Flat leaves • No prey capture • High concentration of chlorophyll, stomates • Photosynthetically more efficient than pitchers

  15. Flowering Stalks • Single stalk per rosette • Flowering after3 to 5 years • Bumblebee, fly pollinated • Short-distancedispersal of seeds

  16. Leaf Senescence • End-of-season die off • Production of new leaves in following spring • Annual increase in rosette diameter

  17. Effects of N Deposition on Carnivorous Plants • Life History • Effects on Individuals • Effects on Populations • Effects on Communities • The Role of Ecologists

  18. Distilled H20 Micronutrients Low N (0.1 mg/L) High N (1.0 mg/L) Low P (0.025 mg/L) High P (0.25 mg/L) N:P(1) Low N + Low P N:P(2) Low N + High P N:P(3) High N + Low P Nutrient Treatments Nutrient Source: Micronutrients: Hoaglands N: NH4Cl P: NaH2PO4

  19. Anthropogenic N additions alter growth and morphology

  20. Anthropogenic N additions alter growth and morphology Increasing N

  21. Effects of Anthropogenic N additions • Increased production of phyllodia • Phenotypic shift from carnivory to photosynthesis • Increased probability of flowering

  22. Contrasting effects of anthropogenic N vs. N derived from prey

  23. Food Addition Experiment • Ecological “press” experiment • Food supplemented with house flies • Treatments: 0, 2, 4 ,6, 8,10,12, 14 flies/week • Plants harvested after one field season

  24. Food additions donot alter growth and morphology Increasing prey

  25. N uptake increases with food level

  26. P uptake increases with food level

  27. N:P ratio decreases with increasing food supply

  28. Altered N:P ratios suggestPlimitation under ambient conditions Ambient P limitation(Koerselman & Meuleman 1996, Olde Venternik et al. in press)

  29. Food additions donot alter growth and morphology Increasing prey

  30. Anthropogenic N additions alter growth and morphology Increasing N

  31. Anthropogenic N Altered N:P ratios Morphological shift Reduction in prey uptake Prey N Uptake, storage of N & P No morphological shifts Continued prey uptake Contrasting effects of anthropogenic and natural sources of N

  32. Effects of N Deposition on Carnivorous Plants • Life History • Effects on Individuals • Effects on Populations • Effects on Communities • The Role of Ecologists

  33. Study Sites

  34. Demography survey • 100 adult, juvenile plants tagged at each site • Plants censused and measured each year • Seed plantings to estimate recruitment functions

  35. Sarracenia matrix model Flowering Adults Recruits Juveniles Adults

  36. Hawley Bog Transitions 4.00 0.10 0.18 0.04 Flowering Adults Recruits Juveniles Adults 0.09 0.83 0.95 0.70 0.17

  37. Molly Bog Transitions 4.00 0.13 0.10 0.10 Flowering Adults Recruits Juveniles Adults 0.17 0.66 0.85 0.71 0.31

  38. Matrix Transition Model(stationary) nt+1 = Ant Population vector at time (t) Population vector at time (t + 1) Transition matrix

More Related