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. K E Y W O R D S alien, chronosequence, diversity, endemism, island, lava flow, primary succession, structural equation model, vascular plants 588 | Journal of Vegetation Science IRL et aL. | 589 Journal of Vegetation Science IRL et aL.

Mit dem Volksbegehren Artenvielfalt wurden Änderungen im Bayerischen Naturschutzgesetz für besseren Arten- und Biotopschutz angestoßen. Auf Basis einer Literaturstudie betrachten wir, welches Potenzial diese Änderungen auch für Ökosystemdienstleistungen in der Agrarlandschaft haben können.The Bavarian referendum Biodiversity and Natural Beauty (Volksbegehren Artenvielfalt) has led to significant changes in Bavarian environmental legislation. This article investigates and assesses the potential impact of the referendum on ecosystem services (ES) based on existing literature. For this purpose, we selected all the legislative changes that are assumed to directly impact ES in agricultural landscapes. Little research exists on many of the specific relationships for the legislative changes discussed, particularly concerning cultural ES. Nonetheless, for the majority of the legislative changes, the reviewed studies suggest a positive impact on ES. Although we did not find any neutral or negative effects on ES, they are possible in individual cases based on local site conditions and the specific design of the measures. Habitat function and genetic resource maintenance are likely to benefit the most from the legislative changes. Yet, many other ES may be positively influenced, especially in combination with funding law measures and the planned positions for wildlife habitat and biodiversity advisors. The actual effects in Bavarian landscapes should be scientifically investigated.