Empirical critical loads for N deposition effects and maps showing areas projected to be in
exceedance of the critical load (CL) are given for seven major vegetation types in California …

For two decades, the US Department of Agriculture, Forest Service, has been charged with
implementing a nationwide field-based forest health monitoring effort. Given its extensive …

Human activity in the last century has led to a significant increase in nitrogen (N) emissions
and atmospheric deposition. This N deposition has reached a level that has caused or is …

Critical loads (CLs) define maximum atmospheric deposition levels apparently preventative
of ecosystem harm. We present first nitrogen CLs for northwestern North America's maritime …

Empirical critical loads (CL) for N deposition were determined from changes in epiphytic
lichen communities, elevated NO3− leaching in streamwater, and reduced fine root biomass …

We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate
forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to …

Nitrogen (N) deposition has increased globally over the last 150 years and further increases
are predicted. Epiphytic lichens decline in abundance and diversity in areas with high N …

Cyanolichens are obligate symbioses between fungi and cyanobacteria. In these
associations the cyanobacterial symbiont can either be the sole photosynthetic partner or a …

Many global ecosystems have undergone shifts in fire regimes in recent decades, such as
changes in fire size, frequency, and/or severity. Recent research shows that increases in fire …

Epiphytic lichen communities are highly sensitive to excess nitrogen (N), which causes the
replacement of native floras by N‐tolerant,“weedy” eutrophic species. This shift is commonly …