An ecological perspective on ‘plant carnivory beyond bogs’: nutritional benefits of prey capture for the Mediterranean carnivorous plant Drosophyllum lusitanicum

Abstract

Background and aims Little is known about the evolutionary and ecological drivers of carnivory in plants, particularly for those terrestrial species that do not occur in typical swamp or bog habitats. The Mediterranean endemic Drosophyllum lusitanicum (Drosophyllaceae) is one of very few terrestrial carnivorous plant species outside of Australia to occur in seasonally dry, fire-prone habitats, and is thus an ecological rarity. Here we assess the nutritional benefits of prey capture for D. lusitanicum under differing levels of soil fertility in situ. Methods We measured the total nitrogen and stable nitrogen and carbon isotope ratios of D. lusitanicum leaves, neighbouring non-carnivorous plant leaves, and groups of insect prey in three populations in southern Spain. We calculated trophic enrichment (ε15N) and estimated the proportion of prey-derived nitrogen (%Nprey) in D. lusitanicum leaves, and related these factors to soil chemistry parameters measured at each site. Key results In all three populations studied, D. lusitanicum plants were significantly isotopically enriched compared with neighbouring non-carnivorous plants. We estimated that D. lusitanicum gain ~36 %Nprey at the Puerto de Gáliz site, ~54 %Nprey at the Sierra Carbonera site and ~75 %Nprey at the Montera del Torero site. Enrichment in N isotope (ε15N) differed considerably among sites; however, it was not found to be significantly related to log10(soil N), log10(soil P) or log10(soil K). Conclusions Drosophyllum lusitanicum individuals gain a significant nutritional benefit from captured prey in their natural habitat, exhibiting proportions of prey-derived nitrogen that are similar to those recorded for carnivorous plants occurring in more mesic environments. This study adds to the growing body of literature confirming that carnivory is a highly beneficial nutritional strategy not only in mesic habitats but also in seasonally dry environments, and provides insights to inform conservation strategies for D. lusitanicum in situ.

Effects of crossing distance on fitness components in the carnivorous plant Pinguicula moranensis (Lentibulariaceae)

“…It is well known that carnivorous plants benefit from the interaction with insects caught in their traps (Cook, Newton, & Millett, 2017;Ne'eman, Ne'eman, & Ellison, 2006;Schulze, Schulze, Schulze, & Oren, 2001;Skates et al, 2019). However, as occurs in most angiosperm species, the flowers of carnivorous plants are expected to be visited by insects (Ollerton, Winfree, & Tarrant, 2011).…”

Leaf NPK stoichiometry, δ15N, and apparent nutrient limitation of co‐occurring carnivorous and noncarnivorous plants

“…δ 13 C can also be used to estimate stomatal conductance, transpiration, and photosynthesis of traps versus noncarnivorous leaves (Ellison & Adamec, 2011;Klink et al, 2019;Pavlovič & Saganov a, 2015). Because Schulze et al (1991) introduced the linear two-source mixing model, the model has been used frequently to quantify the mineral nutrition of carnivorous plants (Klink et al, 2019;Lin et al, 2021;Midgely & Stock, 1998;Schulze et al, 1991Schulze et al, , 2001Skates, 2021;Skates et al, 2019). Such studies indicate that prey contribute 10%-90% of total N for carnivorous plants (Ellison & Gotelli, 2001).…”

“…These data, however, confound the effects of carnivory and habitat, given that almost all carnivorous plants grow in nutrient-poor habitats and most noncarnivorous species analyzed by Ellison (2006) grow in more fertile habitats (Givnish et al, 2018). Carnivores gain a considerable portion of their limiting nutrients, especially N and P, from insect prey (Klink et al, 2019;Lin et al, 2021;Midgely & Stock, 1998;Schulze et al, 1991Schulze et al, , 2001Skates et al, 2019), in some cases reducing or ceasing production of traps versus more photosynthetically efficient tissue under conditions of increased N deposition (Ellison & Gotelli, 2002).…”

Do Cuticular Gaps Make It Possible to Study the Composition of the Cell Walls in the Glands of Drosophyllum lusitanicum?

“…However, in contrast to most carnivorous plants, Drosophyllum lusitanicum (L.) Link inhabits heathlands and ruderal sites with both very tough climatic and pedological conditions. In these places, Drosophyllum is exposed to an extreme climate with very high air and soil temperatures and very low air humidity throughout the day [16][17][18]. According to Adamec [19], Drosophyllum tissues do not store water.…”