Vascular epiphytes contribute disproportionately to global centres of plant diversity

Aim: Vascular epiphytes are ubiquitous features of wet tropical forests where they contribute substantially to local and regional plant diversity. While some basic epiphyte distribution patterns are relatively well studied, little effort has been made to understand the drivers responsible for constraining their global distribution. This study quantifies the substantial contribution of epiphytes to global gradients and centres of vascular plant diversity and explores whether epiphytes vary from terrestrial plants in relation to contemporary and historical environmental variables. Location: Global. Time period: Present. Major taxa studied: Vascular epiphytes. Methods: We integrated EpiList 1.0, a comprehensive list comprising > 30,000 vascular epiphyte species, and species distributions derived from the GIFT database to describe the global biogeography of epiphytes. We used generalized linear mixed effects models to assess the relationship between epiphytic and terrestrial plant diversity, and contemporary and historical environmental predictors. Results: We find that epiphytes substantially contribute to global centres of vascular plant diversity, accounting for up to 39% of the vascular flora in the Neotropics. Epiphytes decrease in species numbers with increasing latitude at a rate three times faster than terrestrial plants, a trend that is driven mainly by the distribution of tropical forests and precipitation. Further, large regional differences emerge that are explained by several large endemic angiosperm families (e.g., Neotropical Bromeliaceae) that are absent in other tropical regions. Main conclusions: Our results show that epiphytes are disproportionately diverse in most global centres of plant diversity and play an important role in driving the global latitudinal diversity gradient for plants. The distribution of precipitation and tropical forests emerge as major drivers of the latitudinal diversity gradient in epiphyte species richness. Finally, our findings demonstrate how epiphyte floras in different biogeographical realms are composed of different families and higher taxa revealing an important signature of historical biogeography.

Vascular plant biodiversity of Dorset and Mallik islands, Nunavut, Canada: an annotated checklist of a middle Arctic flora in the Canadian Arctic Archipelago

Establishing a baseline of current Arctic vascular plant diversity and distribution is critical, given the rapid and major environmental changes occurring in the Arctic ecozone in response to climate change. Here, we report the results of a floristic study of vascular plant diversity of Dorset and Mallik islands in the Canadian Arctic Archipelago, Nunavut, Canada. These two small islands lie off the coast of the Foxe Peninsula of southwestern Baffin Island, and they are part of the Circumpolar Arctic bioclimate Subzone C. The hamlet of Kinngait (formerly Cape Dorset) is located on Dorset Island, and Nunavut’s Mallikjuak Territorial Park encompasses all of Mallik Island. The study is based on a specimen-based dataset comprising 876 unique collections from the two islands gathered over the last century, including 268 new ones collected in 2015. Results are presented in an annotated checklist. The vascular plant flora of the study area comprises 26 families, 71 genera, 150 species and three infraspecific taxa; 139 species are recorded on Dorset Island and 102 on Mallik Island. Eleven taxa are newly recorded from the study area in six families: Carex rupestris, Eriophorum scheuchzeri subsp. scheuchzeri, E. triste (Cyperaceae); Diapensia lapponica (Diapensiaceae); Equisetum arvense subsp. alpestre (Equisetaceae); Oxytropis deflexa var. foliolosa (Fabaceae); Potentilla arenosa subsp. arenosa, P. hyparctica subsp. hyparctica (Rosaceae); Antennaria friesiana subsp. friesiana, Askellia pygmaea, and Taraxacum phymatocarpum (Asteraceae).

Relationship between moth (night active Lepidoptera) diversity and vegetation characteristics in southern Sweden

The diversity and community composition of moths (both macro- and micromoths) at 32 sites, representing a wide range of habitat types (forests, grasslands, wetlands, agricultural and urban areas) within a restricted region in central Scania, southern-most Sweden, was investigated by use of light moth traps and compared with vascular plant species richness and habitat characteristics. The results revealed a highly significant general association between vegetation composition and the composition of the moth community and multivariate (CCA) analyses indicated light availability and soil fertility parameters (pH and macronutrients) to be the habitat characteristics that best correlated with moth community composition. Less strong, but still significant, positive relationships between moth abundance and local vascular plant diversity were also revealed. Moth species richness was positively correlated with diversity of woody plant genera in the neighborhood, but not with local vascular plant diversity in general. As for more general site characteristics, there were tendencies for higher moth richness and abundance at sites with more productive soils (well-drained, high pH, high nutrient availability), while shading/tree canopy cover, management, soil disturbance regimes and nectar production appeared unrelated to moth community parameters. It is concluded that local moth assemblages are strongly influenced by site characteristics and vegetation composition. Implications for insect conservation: The results show that obtaining moth data on a local scale is useful for conservation planning and does not need to be very cumbersome. Local moth assemblages monitored are indeed related to local site characteristics of conservation relevance.