Is a tree a tree? Evaluating differences between red maple and upland oaks in eastern Kentucky Heather D. Alexander and Mary A. Arthur, University of Kentucky, Department of Forestry and Biology

What is the ecological problem? How could these differences affect How can we assess these parameters? What do the data tell us? • Fire suppression in • Oaks (Quercus spp.) are nitrogen and carbon cycling? historically oak-dominated generally competitively Throughfall/Stemflow Throughfall/Stemflow forests of the eastern U.S. has inferior under these 175 150 125 100 facilitated the spread of fire- conditions and often )

-2 75 50 Aug ’06 Oct ’06 Feb ’07 May ’07 Input 100

+ 20 sensitive species like red experience regeneration 4 A 90 15

80 (mg m maple (Acer rubrum), leading failure. NH 70 10 Throughfall: 60 5 B 50 0 B A A to low understory light. • After a rainfall event, a 40 250 B 30 200 B

Volume(cm*) AB 20 150 A B B A B B B

rain dripping ) polyurethane foam collar 100 -2 10 50

Input 0

- 10 • A shift in overstory funnels stemflow into an 80-L 3 Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO

from leaves (mg m Throughfall Stemflow composition could have collection bin. NO 5 Throughfall Stemflow Throughfall Stemflow Throughfall Stemflow and branches 0 numerous ecological and • Compared2000 to scarlet (SO) and chestnut oaks (CO), red maples 1500

• Two funnels attached to 2-L ) 1000 economical consequences, + non- (RM)-2 500 generated similar throughfall and more stemflow volume.

Input

as many species depend on bottles collect throughfall on 80

(mg m 60 intercepted TON 40 oak acorns for their survival, opposite sides of tree. 20 Aug ’06 Oct ’06 Feb ’07 May ’07 0 A and oaks are a highly rain 2000 A 1500 AB B A

) B • Similar collectors in open 1000 B sought after, valuable timber -2 B B 3000500

)

Input

-2 80 species. areas collect rainfall. 2500 A Influenced by: TN (mg m 60 B B 200040 150020 • Leaf area 0 • Water samples are analyzed 1000 Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Precip RM CO SO RM CO SO • Altered composition could also affect ecosystem processes like • Canopy depth and width 500 Throughfall Stemflow Throughfall Stemflow Throughfall Stemflow Throughfall Stemflow

for volume and nitrogen and TIC Input (mg m • Leaf morphology 0 nitrogen (N) and carbon (C) cycling due to interspecific ) carbon quantity. -2 20000 • Red15000 maples also produced more total nitrogen (TN) via throughfall differences in canopy and leaf characteristics which affect 10000 5000 cycling via throughfall, stemflow, and leaf litter decomposition. in winter400 and via stemflow in summer, winter, and spring. 300 200 100 Aug ’06 Oct ’06 Feb ’07 May ’07

TOC Input (mg m 0 A

) 20000 B B -2 A 15000 A Red maple Scarlet oak Chestnut oak 10000 B AB 5000 Why are oaks important? 400 300 200 100

TC Input (mg m • Large genus (~ 500 species) 0 Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO Prec RM CO SO RM CO SO • Dominant in many biomes Throughfall Stemflow Throughfall Stemflow Throughfall Stemflow Throughfall Stemflow • Acorns (keystone species) Precipitation • Ecological processes (foundation Red maple Chestnut oak species) Stemflow: Scarlet oak rain flowing • Oaks generated more total carbon (TC) in fall via stemflow,

but TCPrecipitation input from red maples was greater in winter. down Red maple Chestnut oak branches and Scarlet oak trunk Leaf Litter Leaf Litter

Influenced by: • Leaves are collected from • Crown area • Red maple litter initially The creation of a thousand forests trees in fall. 0.8 is in one acorn. • Branch inclination had lower N concentration ) • Basal area -1 than either oak and • They are transported to the - Ralph Waldo Emerson • Bark texture 0.6 treatments with varying lab and sorted by species.

• Lichen cover N (mg g Red maple amounts of red maple + oak 75% Red Maple 0.4 litter. However, as the litter • Leaves of different species of 50% Red maple 25% Red maple decomposed, samples with How do upland oaks known amount are placed in Scarlet oak Chestnut oak the most red maple litter small-mesh decomposition 1.0 gained the most N. and red maple differ? bags.

0.9 • Samples with the most red Canopy • Bags are placed in the field Bark Leaves maple litter also lost the and retrieved at set intervals to 0.8 most mass overtime, while

determine mass loss over time. Mass loss (%) chestnut oak litter 0.7 decomposed slowest. • Leaves are analyzed for carbon and nitrogen. 0 1 2 3 4 5 6 7 8 9 Time (mo)

Upland Oaks Upland Leaf Litter: leaves dropped

primarily in fall Conclusion

Influenced by: • OVERALL, RED MAPLES CAN DIFFER FROM UPLAND Special Thanks to… • Leaf area OAKS IN THEIR NITROGEN AND CARBON CYCLING

• Leaf morphology Red maple Red • Leaf chemistry VIA STEMFLOW AND DECOMPOSITION, SUGGESTING POTENTIAL ECOSYSTEM-LEVEL CONSEQUENCES OF College of Arts and Sciences A CANOPY SHIFT. Department of Biology