Kara Phelps

1.  
Kara Phelps
SUNY-ESF

2.  Trees retranslocate elements from senescing leaves
 Helps establish nutrient balance in trees
 Nutrient conservation and recycling

3.  What can green leaf concentrations tell us about
limitation?
 Can we see N and P interactions in resorption?
 ARE WE THERE YET?!

4. What did
Craig See
(see)?
See et al. 2015.
Ecology. 96(9).

5.  N resorption
efficiency
correlated with
green leaf P
o NOT with green
leaf N!
 P resorption
efficiency
correlated with
green leaf N
o NOT with green
leaf P!
2014 data in C2

6. Field Methods
 Green leaves in August
 Leaf litter in October
 Eight stands
o Bartlett
• C4, C6, C8, C9
o Hubbard Brook
• HBM, HBO
o Jeffers Brook
• JBM, JBO
 Three species
o Beech (all stands)
o Red maple (mid-aged)
o Sugar maple (old)

7.  Green leaf N
higher with N
 Lower with P!
 Green leaf P
higher with P
 No effect of
N!

10.  The percent difference between green leaf and litter
concentrations of an element
𝑛𝑢𝑡𝑟𝑖𝑒𝑛𝑡 𝑔𝑟 − 𝑛𝑢𝑡𝑟𝑖𝑒𝑛𝑡 𝑠𝑒𝑛
𝑛𝑢𝑡𝑟𝑖𝑒𝑛𝑡 𝑔𝑟

12.  Green leaves
o Green leaf N lower when P added
o Green leaf P not affected by N treatment
o N:P ratios indicate that trees in control plots are P-limited or co-
limited; adding a nutrient shifts limitation
 Leaf litter
o Litter N higher with nitrogen fertilization, with or without P
o Litter P higher with phosphorus added, with or without N
 Resorption efficiency
o Nitrogen – no effect of treatment!
o Phosphorus accumulation = negative resorption efficiency!

13. The B9 bunch and Shoestring
crews, past and present
Ruth Yanai, Mariann Johnston,
Dylan Parry