Response of inland dune vegetation to increased nitrogen and phosphorus levels

Abstract

Question How does pioneer vegetation of acid inland dunes respond to addition of nitrogen (N) and phosphorus (P)? Location Two inland dune reserves in The Netherlands with low and high N deposition. Methods During 2.5 yr, N and P addition (control, N, P, NP) took place in three different vegetation types of inland dunes (Polytrichum piliferum mats, Campylopus introflexus mats and lichen‐dominated vegetation). In each site, changes in the vegetation were recorded in three replicate quadrats of 1 m × 1 m per treatment. Differences in element content of grasses and lichens were recorded, together with vegetation parameters, including cover and height of grasses, bryophytes and lichens. Results In the site with high N deposition, grasses were taller, had higher N:P ratios and a generally lower lichen cover than in the low‐deposition area. Experimental N application resulted in higher N and lower base metal concentrations in grasses and an increase in grass cover and size. In contrast, lichens showed a general decline in the N treatment and the lichen:grass ratio decreased. The effect of N addition was larger in the low‐deposition area. The P treatment had an opposite effect: lichens increased in size and cover and overgrew grasses, especially when reindeer lichens were present. This suggests that the cryptogam layer was P‐limited even in the low N deposition site. Conclusions Pioneer vegetation in inland dunes is susceptible to N and P addition. The results provide evidence for a decrease in lichen cover due to increased N deposition.

Response of the nitrogen‐fixing lichen Lobaria pulmonaria to phosphorus, molybdenum, and vanadium

“…We considered differences in climate and N deposition as among the leading possible explanations for the difference in results of the two experiments. Differences in N deposition could influence lichen growth directly due to cyanolichen sensitivity to ambient N, as well as indirectly via interactions between N and P (e.g., Hogan et al 2010, Johansson et al 2011, Sparrius et al 2013). Although high ambient N can cause down-regulation of N-fixation, both sites had similar estimated N deposition, suggesting that deposition did not alter response to P-fertilization at one site versus the other.…”

“…Because N deposition rates can interact with P cycling in lichens (Hogan et al 2010, Sparrius et al 2013), we estimated total N deposition at the sites of both experiments. In particular, we expected that elevated N deposition might suppress N-fixation and growth at the Wren field site, given its closer proximity to developed areas of the Willamette Valley.…”

Effect of geomorphology and nitrogen deposition on rate of vegetation succession in inland drift sands

“…We indeed observed that the relative cover of the Campylopus vegetation class is much higher in regions with high N deposition in both active and more stabilized drift sand. The quality of pioneer vegetation thus is indeed strongly influenced by the atmospheric input of N, as also documented by Sparrius et al (2013).…”

“…The quality of pioneer vegetation thus is indeed strongly influenced by the atmospheric input of N, as also documented by Sparrius et al. ().…”

Monitoring Lichen as Indicators of Atmospheric Quality

“…This scale has been widely applied in different countries (Bates et al 1990;Khalil and Asta 1998;Svoboda 2007;Lisowska 2011). However, such scale designed to assess SO 2 may no longer be accurate indicator of atmospheric pollution because SO 2 levels in many areas have declined meanwhile nitrogen deposition in urban and agricultural areas is the main driver of lichen communities changes (Larsen et al 2007;Mayer et al 2009;Rogers et al 2009;Grandin 2011;Johansson et al 2012;Evju and Bruteig 2013;Sparrius et al 2013). Zone scales as the biomonitoring approach allow predicting the level of pollution by sulphur dioxide from the assemblages of lichen species typical for unaltered habitat.…”