Message - 7th IAL Symposium

Lichen: from genome to ecosystem in a changing world
2B-P
(2B-P20) Submission ID: IAL0017-00001
IS LICHEN SPECIES RICHNESS LINKED TO LAND COVER PATTERN AT LARGE SCALES IN
FORESTS ACROSS THE USA?
Will-Wolf S. 1 , Morin R. S. 2 , Ambrose M. J. 3 , Riitters K. 4 , Jovan S.E. 5
1 Botany, University of Wisconsin, Wisconsin / Madison, Wisconsin, United States
2 Northern Research Station, USDA Forest Service, Pennsylvania / Newtown Square, United States
3 Forestry & Environmental Resources, North Carolina State University, North Carolina / Raleigh, United States
4 Southern Research Station, USDA Forest Service, North Carolina / Raleigh, United States
5 Pacific Northwest Research Station, USDA Forest Service, Oregon / Portland, United States
We studied the response of Lichen S, an index of lichen species richness, to five land cover metrics in
six large regions of the coterminous USA. We found in an earlier study that climate and pollution explain 20-40%
of variation in Lichen S in these same regions. Lichen S is number of macrolichen species from timed samples
of fixed-area forested plots, using data from a national USA forest inventory. Our questions were 1) is land cover
correlated with Lichen S across large regions, 2) is land cover correlated with climate and air quality, and 3) does
inclusion of land cover variables improve analyses of Lichen S response? Our analysis tools, correlation and
linear regression with ranked data, gave robust results comparable across regions, at some cost of lower statistical
power. In three western USA regions strong correlations between climate and land cover suggest climate is
more important to explain Lichen S. In three eastern USA regions we found an effect of land cover on Lichen S
independent from climate and pollution. We found response of Lichen S to land cover was mostly stronger as
size of area evaluated around a plot increased, with much variability between regions. Percentage of nearby
area forested was the single most useful land cover metric, though no single land cover variable or response
model was best in all regions. We found that climate, pollution, and land cover together explain 30-47% of variation
in Lichen S at least for eastern USA; an improvement from the previous study. Several follow-up studies are
suggested.
(2B-P21) Submission ID: IAL0278-00001
COMPARISON OF THE DIVERSITY OF GRAPHIS SPECIES IN DIFFERENT VEGETATION
TYPES IN MEXICO
Bárcenas A. 1 , Herrera-Campos M. 1 , Miranda González R. 1 , Lücking R. 2
1 Botanica, Instituto de Biologia Unam, Coyoacan, Distrito Federal, Mexico
2 Botany, The Field Museum, Chicago, Illinois, United States
Patterns and processes leading to the heterogenous distribution of biodiversity can be studied altitudinally,
latitudinally, in different environments and with different degrees of anthropogenic disturbance, and
focusing on different taxa. In this study we investigate the ecogeographical distribution of the genus Graphis
(Graphidaceae). This genus exhibits a wide tropical distribution and high species diversity, with over 300
accepted species. We compared the species diversity and composition of Graphis in Mexico in two contrasting
ecosystems: the Tropical Rain Forest in Los Tuxtlas, Veracruz and the Tropical deciduous forest in Chamela,
Jalisco. For each site, the Graphis species, the pH bark and DBH of the colonized phorophytes, and seasonal
fluctuations in light and evaporation were recorded along ten points each within three 450 m transects, considering
both the canopy and the understory. Alpha, beta, and gamma diversity were calculated. The structure of Graphis
communities for each ecosystem was analyzed using X2 and Kruskal Wallis ANOVA, as well as cluster and
NMS analyses. The highest species diversity was found in the canopy of the tropical rain forest, where constantly
high values of light and evaporation were recorded during the two seasons. On the other hand, in the Tropical
deciduous forest, the number of species was lower, and no correlation with environmental parameters was. At
both sites, a low correlation was found between species diversity and bark pH and DBH of the trees.
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