Spatiotemporal dynamics of plant diversity and endemism during primary succession on an oceanic‐volcanic island

• Published in: Journal of vegetation science Vol. 30; no. 4; pp. 587 - 598
• Main Authors: Irl, Severin D. H., Schweiger, Andreas H., Hoffmann, Samuel, Beierkuhnlein, Carl, Hartmann, Hanna, Pickel, Thomas, Jentsch, Anke, Acosta, Alicia Teresa Rosario
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01-07-2019
• Subjects: alien; Aquatic plants; Biodiversity; Bryophytes; chronosequence; diversity; Ecological succession; Endemic plants; Endemic species; Endemism; Environmental factors; Flowers & plants; Generalized linear models; Indigenous species; island; Lava; lava flow; Lava flows; Partitioning; Phosphorus; Plant diversity; Plants; primary succession; Soil analysis; Soil moisture; Soil properties; Species diversity; Species richness; Statistical models; structural equation model; Structural equation modeling; vascular plants; Volcanic islands
• ISSN: 1100-9233; 1654-1103
• DOI: 10.1111/jvs.12765

Questions
How does the diversity of native, endemic and alien plant species, as well as the diversity of plant life forms, change during primary succession on lava flows of an oceanic‐volcanic island? How do environmental factors such as moisture and soil properties alter diversity during primary succession?
Location
La Palma, Canary Islands.
Methods
We recorded vascular plants and bryophytes in 210 plots on a chronosequence of nine lava flows spanning approx. 6,000 years and covering an elevational range of 1,100 m. In a subset (n = 78 plots) we collected and analyzed soil samples for soil nitrogen and plant‐available phosphorus. We used generalized linear models, variance partitioning and structural equation models (SEMs) to analyze the data.
Results
Species richness, endemic richness and alien richness increased with time. Natives dominated during early successional stages, whereas endemics and aliens increased with time. At early successional stages, vascular plants and bryophytes had an equal contribution to the species pool, while vascular plants increased up to an 80% contribution at later stages. In the variance partitioning and SEMs, time was the only consistent factor influencing different aspects of diversity during succession (species richness, endemic richness and percent endemism). Only for percent endemism did soil attributes have a substantial impact.
Conclusion
Primary succession on lava flows on La Palma shows a pattern of increasing overall diversity, endemism and alien richness with time. Time is the only factor consistently explaining diversity and endemism, indicating that environmental influences such as climate and soil properties do not substantially alter them during primary succession. Our study contributes to understanding how different facets of diversity assemble through time by using an understudied, yet important island system, and, for the first time, specifically addresses how endemics contribute to the process of primary succession.
We use nine lava flows (max. age 6,000 years) to test how native, endemic and alien plant diversity as well as life forms change during primary succession on La Palma (Canary Islands). Richness increases with time; however, the contribution of natives, endemics and aliens as well as life form strongly varies. Time is the dominating factor explaining diversity.