Pine forest lichens under eutrophication generated by a great cormorant colony

Abstract

Lichen community changes were investigated on trees within a colony of great cormorants (Phalacrocorax carbo sinensis) established in a pine forest on the Curonian Spit, western Lithuania. The impact of birds on the forest has altered the number and characteristics of substrata available to lichens. The lowest number of lichen species and occurrences was registered on trees in the most active part of the colony with the highest nest density. Lichen community patterns were most strongly related to P and Ca content in substrata and pH values. Some acidophytic species showed negative correlations, both with long-term and short-term ornithogenic influence. However, three acidophytes (Chaenotheca ferruginea, Lepraria incana, Coenogonium pineti) demonstrated an affinity for the transitional zone and recently occupied trees, and furthermore, C. pineti apparently reacted positively to a shortterm ornithogenic influence but negatively to a long-term one. These three lichens, along with algae, were the main, and often the only, components of epiphytic communities on trees at the edge of the colony and apparently indicated the crucial point of the acidophytic community under the increasing load of nutrients. All nitrophytic species showed an affinity for a long-term bird influence and reacted negatively to a short-term influence. Only free-living algae (predominating species Desmococcus olivaceus) showed a clear affinity for trees occupied by bird nests. Hypogymnia physodes was found to be an indicator for early environmental changes following eutrophication. The study also showed that high concentrations of P did not have a mitigating effect on the detrimental impact brought about by increases in N and pH levels, but was possibly equally detrimental to acidophytic lichens.

Mammals under a colony of great cormorants: population structure andbody condition of yellow-necked mice

“…Although the active influence of the colony in Zone C had already ceased, the amounts of N, P, and Ca in the soil of this zone in 2010-2011 were higher than in other zones of the colony, with a soil pH of 3.36 ± 0.28 (Adamonytė et al, 2013). In this zone, the diversity of myxomycetes had been somewhat restored (Adamonytė et al, 2013), and both nitrophilous lichens and those characteristic to mixed forests were recorded (Motiejūnaitė et al, 2014). As of yet, there have been no investigations on the time required for small mammals to reestablish diversity and abundance after cormorants no longer breed.…”

“…Consumption of plants and detritus high in N may lead to an increase in the body size of herbivorous or detritivorous organisms (Anderson and Polis, 1999). However, negative impacts of the colonies are not uncommon in fungi (Osono, 2012;Adamonytė et al, 2013), lichens (Źółkóś et al, 2013;Motiejūnaitė et al, 2014), plants (Adamonytė et al, 2013), and insects (Kolb et al, 2012). Positive impacts may also be recorded in some species of lichens (Motiejūnaitė et al, 2014) and insects (Kolb et al, 2012).…”

“…The biggest decrease was observed in mycorrhizal species, but at the same time, coprophilous fungi appeared in the forest litter and specialised fungi species were recorded on plants (Kutorga et al, 2014). Due to altered pH, as well as the content of N, P, and Ca, lichen diversity was also affected, mostly in the active zone of the great cormorant colony (Motiejūnaitė et al, 2014).…”

Estimation of life history in corticolous lichens by zonation

“…In our material, however, it also occurred on the very smooth bark of Abies . The versatility of L. incana was noted in a study by Motiejünaitė et al (2014) where the leprose lifeform was judged to be well adapted to rugose bark and cork accumulation, as seen in the old stem parts of Pseudotsuga and Quercus .

Fig. 3Relationship between stem age (as a proxy for bark age) and cumulative lichen density (as a proportion of total records throughout main stem).

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Decline of a protected coastal pine forest under impact of a colony of great cormorants and the rate of vegetation change under ornithogenic influence

“…Simultaneously, other biotic components of the invaded ecosystem undergo dramatic changes. These changes include shifts in the communities of lichens, myxomycetes, small mammals, arthropods, soil bacteria and archaea (Kolb et al 2012;Adamonytė et al 2013;Źółkóś et al 2013;Balčiauskienė et al 2014;Motiejūnaitė et al 2014;Domínguez et al 2017), as well as decreases in fungal growth and litter decomposition by fungi (Osono et al 2002(Osono et al , 2006 and the fungi/bacteria PLFA ratio in soil (Wright et al 2010). The detrimental effect of cormorant colonies on vegetation is evident from decreases in species richness and abundance, as well as changes in species composition (Ishida 1996;Craig et al 2012;Kolb et al 2012), population dynamics (Calviño-Cancela 2002), and vegetation productivity (Anderson and Polis 1999).…”