För ungefär en månad sedan uppmärksammade vi en forskningsartikel som handlade om hur grågåsen genom sin spillning är viktig för växters spridning på skärgårdsöar i Östersjön (läs inlägget här). Lutz Eckstein, Professor i NRRV, är medförfattare på artikeln.

Nu har forskningen fått stort mediegenomslag, och uppmärksammats av bland annat Sveriges Radio (lyssna på ett inslag där Lutz berättar om studien), Aftonbladet, Svenska Dagbladet, Ny Teknik samt en mängd lokaltidningar (Smålandsposten, Kristianstadsbladet, Bohuslänningen, Enköpingsposten, Borås tidning, Uppsala nya tidning, Katrineholms-Kuriren m.fl.).

Dirk Hattermann, Markus Bernhardt-Römermann, Annette Otte  and Lutz Eckstein recently published the paper “Geese are overlooked dispersal vectors for vascular plants in archipelago environments” in Journal of Vegetation Science.


In the abstract, the authors write:



We addressed the importance of gut‐mediated dispersal by Greylag Goose for vascular plants in archipelago environments and asked:

(i) What proportion of the local species pool is dispersed by geese?.

(ii) Which plant traits characterize species dispersed by geese?.

(iii) Which plant communities are likely to benefit from endozoochory by geese?.



Three Swedish Baltic archipelagos.



Goose droppings were collected on 45 islands. Plants germinating from the droppings represent the endozoochorous species pool (ESP). On 108 islands, the presence of vascular plants was recorded in each habitat. These species represent the island species pool (ISP). Differences in functional traits between ESP and ISP were expressed as effect sizes and tested using meta‐regressions. Using indicator species analyses and indicator species for managed semi‐natural grasslands, we identified the primary habitats of the ESP.



Geese dispersed viable diaspores of 97 plant species, which represents 22% of the ISP. Most ESP species were typical for small islands. Geese dispersed a higher proportion of graminoids and less woody plants, higher proportions of chamaephytes and therophytes and less phanerophytes; annuals and bi‐annuals were significantly overrepresented. One average, seed volume of the ESP was 95 % smaller than that of the ISP. About 51% of all ESP species were dispersed in at least two archipelagos. Geese showed a bias towards species of rocky shore habitats.



Geese potentially disperse large amounts of diaspores of many terrestrial island plant species. Through their feeding behaviour, geese select species with certain suites of traits from the regional species pool. Plant dispersal by geese may benefit plants species of rocky shores, but species of formerly managed semi‐natural grasslands may also find refuge sites on epilittoral shores after goose‐mediated dispersal. The relative importance of geese as dispersal vectors may increase under ongoing land‐use changes and cessation of grazing networks.”


Access the paper here, or contact any of the authors.

Dirk Hattermann (Justus Liebig University Giessen), Markus Bernhardt-Römermann (Friedrich Schiller University Jena), Annette Otte (Justus Liebig University Giessen) and Lutz Eckstein (Karlstad University) recently published the paper “New insights into island vegetation composition and species diversity – Consistent and conditional responses across contrasting insular habitats at the plot-scale” in the scientific journal PLOS ONE.

In the abstract the authors write:

“Most island-ecology studies focus on the properties of entire island communities, thus neglecting species-environment relationships operating at the habitat-level. Habitat-specific variation in the strength and sign of these relationships will conceal patterns observed on the island scale and may preclude a mechanistic interpretation of patterns and processes. Habitat-specific species-environment relationships may also depend on the descriptor of ecological communities. This paper presents a comprehensive plot-based analysis of local vegetation composition and species diversity (species richness and species evenness) of (i) rocky shore, (ii) semi-natural grassland and (iii) coniferous forest habitats in three Baltic archipelagos in Sweden. To identify differences and consistencies between habitats and descriptors, we assessed the relative contributions of the variable-sets “region”, “topography”, “soil morphology”, “soil fertility”, “soil water”, “light availability”, “distance” and “island configuration” on local vegetation composition, species richness and species evenness. We quantified the impact of “management history” on the descriptors of local grassland communities by a newly introduced grazing history index (GHI). Unlike species diversity, changes in vegetation composition were related to most of the variable-sets. The relative contributions of the variable-sets were mostly habitat-specific and strongly contingent on the descriptor involved. Within each habitat, richness and evenness were only partly affected by the same variable-sets, and if so, their relative contribution varied between diversity proxies. Across all habitats, soil variable-sets showed highly consistent effects on vegetation composition and species diversity and contributed most to the variance explained. GHI was a powerful predictor, explaining high proportions of variation in all three descriptors of grassland species communities. The proportion of unexplained variance was habitat-specific, possibly reflecting a community maturity gradient. Our results reveal that species richness alone is an incomplete representation of local species diversity. Finally, we stress the need of including habitat-based approaches when analyzing complex species-environment relationships on islands.”

You can access the paper here.