Liana impacts on tree growth in an early successional temperate forest system Laura M. Ladwig & Scott J. Meiners Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois 61920; [email protected]

Although they are important components of forest communities, lianas (woody vines) are often overlooked in Tree growth 5 Of the three liana burden (cm) variables measured only ecological studies. While lianas have been shown to Species specific 4 damage tropical canopy trees and reduce the growth of canopy cover had a negative

Growth 3 association with tree growth juvenile trees, the impact of lianas on canopy tree growth Early (solid) and late (striped) 2 Radial and was also by far the in temperate systems is largely unknown. successional tree species were fastest sampling technique. separated based on their 1

Absolute Although statistically trees with large amounts of liana canopy cover grew less dominance within the canopy of 0 the adjacent old‐growth forest. than trees with fewer lianas, this model explained little of the variation in tree Acer Trees This research examined established trees to Cornus Prunus growth (roughly 3%). Juglans Quercus Fraxinus All Ailanthus determine whether lianas had an impact on tree Juniperus Based on this research, lianas may not be greatly growth in a series of young, temperate forests. Overall, late successional trees grew 60% more than early successional trees. The difference in growth Specifically, we asked: detrimental to tree and overall temperate forest was probably a result of the timing of measurements during succession. During this time, growth of early health in a young, closed‐canopy forest. However, Are lianas associated with tree growth? successional trees was presumably suppressed by increasing amounts of shade from late successional tree some liana species, C. orbiculatus and Vitis spp., species, in addition to the effects of lianas. are still increasing and may pose future risks to If so, how does it vary with: forest growth and development. ‐ Tree species Tree growth Trees with the most liana canopy ‐ Tree size Successional stage & liana burdens cover grew the least.

5 5 ‐ Liana canopy and trunk abundance 5 Measuring basal area of lianas may 4 4 4 (cm)

(cm) (cm)

be unnecessary as it showed similar Study Site 3 3 3 Growth Growth

Growth

results as stem The Buell‐Small Succession Study (BSS) count but was Radial Radial

Radial

2 2 2 10 abandoned agriculture fields where plant composition within 48 much more time 2 (1m ) permanent plots per field has been monitored annually for the intensive. Absolute 1 Absolute 1 past 50 years. Fields outlined in pink & adjacent to old‐growth forest. 1 Absolute

0 0 0 0 1 ‐ 10 > 10 0< 1 cm2 > 1 cm2 0 1 ‐ 50% > 50% Liana Stem Count Liana Basal Area Liana Canopy Cover Why didn’t we explain much variation in 2 r2 df F p r2 df F p r df F p Model 0.093 5, 600 12.39 <0.0001 Model 0.086 5, 600 11.27 <0.0001 Model 0.096 5, 600 12.75 <0.0001 tree growth? Stem count 2, 600 7.54 0.0006 Basal area 2, 600 5.04 0.0068 Canopy cover 2, 600 6.17 0.0022 Successional stage1, 600 44.56 <0.0001 Successional stage1, 600 54.01 <0.0001 Successional stage1, 600 20.48 <0.0001 Stem * Successional 2, 600 3.1 0.0459 BA * Successional 2, 600 2.76 0.0641 Cover * Successional 2, 600 0.69 0.5003 Methods Many factors Flora Late successional trees (striped) grew the most with higher liana burdens on Trees Lianas All trees with a dbh > 8 cm originating in or having a crown Both early and late successional influence tree Herbs Shrubs Light overhanging a BSS plot were surveyed. trunks, but early successional tree growth (solid) was unaffected by liana load. trees responded similarly to growth. Lianas are Water Trees with the greatest liana basal area and stem counts grew the most, Climate & Tree Growth increased liana canopy cover. an important, but Weather 1999 presumably in places where resources were favorable for both trees and lianas. small component, Fauna Trees diameter measured Nutrients Trees tagged to tree growth in 2008 this system. Disturbance Trees re‐measured Species of Interest Humans Associated lianas measured: ‐ Diameter (basal area) Toxicodendron radicans Parthenocissus quinquefolia (poison ivy) ‐ Number of stems (Virginia creeper) ‐ Percent canopy cover Vitis spp. (grape) Measuring one of 606 trees

On average, each tree supported ‐ 4 liana stems Lonicera japonica Celastrus orbiculatis ‐ 23% of canopy covered by lianas (Japanese honeysuckle) (Oriental bittersweet) ‐ one liana species

Measuring one of 2,708 lianas