Duke Forest (DUKE)

Duke Forest (DUKE)

1996 to current
Aaron Berdanier 30' up
Aaron Berdanier installed sapflux sensors along the tree bole

The portions of the Duke Forest included in this study lie within Durham County and Orange County, NC.  Duke Forest is owned by the university.  Since 1931 it has been managed for teaching and research.  The region was agricultural until the early 20th century, at which point farm abandonment was followed by second-growth pine and, later, hardwoods.  Sites that escaped cultivation, including bottomlands, support large hardwoods and P. taeda.  Establishment and maintenance of our study plots has been made possible by the Duke Forest staff, including Judd Edeburn and, more recently, Sara Childs.

Alan Berdanier spear-headed sapflux studies at DUKE-BW.  Trees were instrumented along an elevation (moisture) gradient and used to evaluate the moisture available to each tree.

Installation of wireless sensor network with Allen McBride, Nathan Welch, and Miranda Welsh.

Through a collaboration with Paul Flikkema at NAU, plots were instrumented with wireless sensor networks in 2010.

Mast masting has been monitored continuously at Duke Forest since 1999.  Seed trap sampling is part of the long-term forest demography plots at the Blackwood (plots HW and BW) and Eno (plots EE and EW) Divisions of Duke Forest.

These sites are the subject of many publications, including the PhD research of David Bell, Aaron Berdanier, Mike Dietze, Michelle Hersh, Ines Ibanez, Shannon LaDeau, Jackie Mohan, Emily Moran, Bijan Seyednasrollah, and Mike Wolosin.

DUKEHW
tree_years seed_count
ailaAlti 108 0
caryOvalGlab 1728 0
caryOvat 1890 0
caryTome 1080 0
caryUNKN 90 99
cercCana 935 0
cornFlor 10656 218
faguGran 36 0
fraxAmer 20520 2303
fraxPenn 126 118
ilexDeci 28098 0
ilexOpac 2178 0
ilexUNKN 0 597
ilexVert 180 0
juniVirg 6156 0
liquStyr 20196 0
liriTuli 4986 0
moruRubr 720 0
nyssSylv 9612 0
ostrVirg 360 0
pinuEchi 18 0
pinuTaed 3528 0
pinuUNKN 0 9386
pinuVirg 18 0
prunSero 846 0
prunUNKN 0 11
querAlba 1332 525
querFalc 72 154
querPhel 1494 688
querRubr 36 80
querStel 828 148
querUNKN 0 657
querVelu 18 0
robiPseu 36 0
sassAlbi 18 0
ulmuAlat 15876 10434
ulmuAmer 3150 804
ulmuRubr 846 22

The Hardwood Plot (DUKE-HW) was established in 1998 just west of the FACE (Free-Air CO2 Enrichment) site.  The coyote at the top of this page was captured by camera trap at DUKE-HW.  This bottom-land hardwood site has saturated soils much of the year.  The diverse canopy includes a mixture of pines and hardwoods.  Sampling at this site was expanded with the implementation of canopy gaps and deer exclosures in 2009.

Experimental canopy gaps, this one at DUKE-BW, have seed traps arrayed across gap openings and into surrounding close forest.
DUKEBW
tree_years seed_count
ailaAlti 408 0
amelArbo 51 7
caryOvalGlab 5423 0
caryOvat 51 0
caryTome 7905 0
caryUNKN 374 106
celtLaev 238 28
cercCana 4377 0
cornFlor 28849 485
faguGran 510 0
fraxAmer 13277 9218
fraxPenn 0 300
ilexDeci 952 0
ilexOpac 918 0
ilexUNKN 153 52
juglNigr 221 2
juniVirg 7348 0
liquStyr 33204 0
liriTuli 7157 0
moruRubr 2951 0
nyssSylv 6545 0
oxydArbo 2788 0
pinuEchi 1411 0
pinuTaed 7956 0
pinuUNKN 0 23140
pinuVirg 425 0
prunSero 697 9
prunUNKN 0 127
querAlba 4743 505
querFalc 748 29
querMari 153 0
querPhel 374 30
querRubr 1445 27
querStel 833 9
querUNKN 0 220
querVelu 442 13
tiliAmer 85 0
ulmuAlat 14970 5506
ulmuAmer 2346 474
ulmuRubr 153 0

The Blackwood Plot (DUKE-BW) was established in 1999 to span a moisture gradient from xeric upland Pinus spp. and Quercus spp. to bottomland P. taeda and Fagus grandifolia.  It has since included canopy gaps, established in 2002 and 2009, and sapflux studies.

DUKEEW
tree_years seed_count
amelArbo 48 0
caryOvalGlab 1140 0
caryOvat 48 0
caryTome 504 0
caryUNKN 60 110
cornFlor 6084 22
faguGran 48 0
ilexDeci 12 0
ilexOpac 24 0
ilexUNKN 0 13
juniVirg 1368 0
liquStyr 8640 0
liriTuli 1152 0
moruRubr 12 0
nyssSylv 12744 0
oxydArbo 20796 0
pinuEchi 240 0
pinuTaed 804 0
pinuUNKN 0 1517
pinuVirg 132 0
prunSero 108 0
prunUNKN 0 54
querAlba 3072 610
querCocc 36 0
querFalc 348 26
querPhel 0 18
querRubr 456 127
querStel 372 5
querUNKN 0 680
querVelu 132 16
ulmuAlat 276 47

The Eno West plot (DUKE-EW) was established in 2003, with a deer exclosure and canopy gaps implemented in 2009.  This upland xeric site has a sparse understory and limited recruitment.  The canopy is dominated by Quercus spp., Acer rubrum, Oxydendrum arboreum, and Nyssa sylvatica.

The genus Pinus at DUKE-BW. Symbols are proportional to tree diameter.
DUKEEE
tree_years seed_count
ailaAlti 40 0
caryOvalGlab 330 17
caryOvat 130 0
caryTome 920 0
caryUNKN 40 7
cercCana 45 0
cornFlor 600 3
faguGran 60 0
fraxAmer 210 2
juglNigr 10 0
juniVirg 260 0
liquStyr 2060 0
liriTuli 10584 0
moruRubr 10 0
nyssSylv 80 0
oxydArbo 240 0
pinuTaed 1473 0
pinuUNKN 0 55
pinuVirg 75 0
prunSero 120 0
prunUNKN 0 1
querAlba 410 4
querFalc 70 1
querPhel 20 0
querRubr 100 25
querUNKN 0 178
querVelu 30 0
ulmuAlat 30 73
ulmuAmer 40 177
ulmuRubr 10 0

The Eno East plot (DUKE-EE) occupies a bottomland, dominated by hardwoods, and an adjacent hillslope with immature P. taeda.  This plot was established in 2007.

The Pinus palustris stand DUKE-PIPA was planted on sandy soils in the Durham Division of Duke Forest in the 1930’s.  It has been maintained with controlled burns.  This site has a cone-count plot established by us in 2018.

The DUKE-PICR site occupies a ridge and bottomland mixed pine and hardwood site.  This forested suburban landscape has a former Duke Forest matrix with interspersed houses on 1/2 to 1 acre tracts.  Crop counts on multiple species were started in 2018.

Shannon LaDeau counts cones from FACE tower

In addition to long-term demography plots, seed traps and cone production were monitored at the time when FACE was active, starting in 1996.  The six FACE rings have plot names DUKE-FACE1, …, DUKE-FACE6.  Cones were counted from the FACE towers.

Non-mast and mast years for Pinus at DUKE-BW.

Climate data include our wireless sensor networks and the RAWS installation at DUKE-BW.

Mast data are described in publications, including:

  • Berdanier, A. and J.S. Clark. 2016. Divergent reproductive allocation trade-offs with canopy exposure across tree species in temperate forests. Ecosphere, DOI:10.1002/ecs2.1313.
  • Bell, D.M. and J.S. Clark 2015. Seed predation and climate impacts on reproductive variation in temperate forests of the southeastern USA. Oecologia, 180, 1223–1234bell2016
  • Clark, J.S., D.M. Bell, M.C. Kwit, and K. Zhu. 2014. Competition-interaction landscapes for the joint response of forests to climate change. Global Change Biology, 20, 1979-1991.
  • Clark, J.S., D. Bell, C. Chu, B. Courbaud, M. Dietze, M. Hersh, J. HilleRisLambers, I. Ibanez, S. L. LaDeau, S. M. McMahon, C.J.E. Metcalf, J. Mohan, E. Moran, L. Pangle, S. Pearson, C. Salk, Z. Shen, D. Valle, and P. Wyckoff. 2010. High dimensional coexistence based on individual variation: a synthesis of evidence. EM2010, 80, 569–608. EM2010appendix-A, EM2010appendix-B
  • Clark, J.S. 2010. Individuals and the variation needed for high species diversity. Science 327, 1129-1132, science2010. scienceAppend2010
  • LaDeau, S.L. and J.S. Clark. 2006. Elevated CO2 and tree fecundity: the role of tree size, interannual variability, and population heterogeneity.  Global Change Biology, 12:822-833.