Topic
Echium simplex
About: Echium simplex is a research topic. Over the lifetime, 3 publications have been published within this topic receiving 10 citations.
Papers
TL;DR: Although the frequency and diversity of diurnal pollinators is far higher than that of nocturnal pollinator, both exhibit different foraging behaviour that generates complementary effects on the reproductive success of E. simplex.
Abstract: Nocturnal pollination plays an important role in sexual plant reproduction but has been overlooked, partially because of intrinsic difficulties in field experimentation. Even less attention has received the effect of within-inflorescence spatial position (distal or proximal) on nocturnal pollinators of columnar plants, despite numerous studies examining the relationship between such position and reproductive success. Woody endemic Echium simplex possesses large erect inflorescences bearing thousands of flowers which are visited by a wide array of diurnal and nocturnal animals. In this study, we identified nocturnal visitors and compared their pollination effectiveness with that of diurnal pollinators in different inflorescence sections by means of selective exclosures in NE Tenerife (Canary Islands). Nocturnal visitors included at least ten morphospecies of moths (such as Paradrina rebeli and Eupithecia sp.), two coleopteran species (mainly Alloxantha sp.), neuropterans (Chrysoperla carnea), dictyopterans (Phyllodromica brullei), dermapterans (Guanchia sp.) and julidans (Ommatoiulus moreletii). In general, plants excluded from pollinators set less fruits than open-pollination (control) plants which set fruits homogeneously across sections. Diurnally pollinated plants set more fruit in their upper parts whereas nocturnally pollinated plants set fruit in both upper and bottom sections. We conclude that although the frequency and diversity of diurnal pollinators is far higher than that of nocturnal pollinators, both exhibit different foraging behaviour that generates complementary effects on the reproductive success of E. simplex.
6 citations
1 Jan 2013
TL;DR: It is concluded that E. simplex despite its restricted occurrence in a small area is not endangered at the moment, but the plant deserves careful observation to allow immediate conservation measures in case of a decline in population size.
Abstract: Echium simplex is one of three giant, monocarpic rosette trees among the 24 endemic species of the genus on the Canary Islands. The plant occurs with few populations at low elevation on the rocky north coast of the Anaga mountains on Tenerife. We studied the by far largest occurrence of E. simplex close to the lighthouse El Faro. The area was formerly agriculturally used, which is still indicated by the occurrence of weedy annuals and nutrient indicator plants. In a census of E. simplex in late April 2011, we counted c. 1300 flowering individuals, a total population size of about 10 000 individuals, and an average of 14.1% flowering individu als in three subsamples of the population. The size of flowering individuals was highly variable; even plants with rather small rosettes were flowering. Similarly, we estimated the age of flowering individuals to vary from 5 to 9 years. Largest individuals had rosettes with 90 cm in diameter and were up to 3 m high, with in florescences of 1.5 m in height. The reproductive output is increasing exponentially with the size of plants and the length of their inflorescences; it amounted to more than 200 000 potential seeds in large individuals. We conclude that E. simplex despite its restricted occurrence in a small area is not endangered at the moment, but the plant deserves careful observation to allow immediate conservation measures in case of a decline in population size.
2 citations
TL;DR: Although the floral resources provided by E. simplex may be important to some vertebrate species, these do not appear to contribute to increase fitness of the plant, which was more dependent upon flying insects for fruit and seed set.
Abstract: Oceanic island ecosystems favour the appearance of novel interactions as a consequence of their depauperate and disharmonic flora and fauna. We investigated Echium simplex, endemic to the Anaga Biosphere Reserve in NE Tenerife, Canary Islands, belongs to the Canarian bird-flower element. Along two flowering seasons, we studied the breeding system of E. simplex, identified the floral visitors and compared the pollination effectiveness of different animal guilds (insects versus vertebrates) by means of selective exclosures. E. simplex is self-compatible but selfing significantly reduced fruit set. The flowers were visited by five bird species (mostly Phylloscopus canariensis and Serinus canarius, but also Cyanistes teneriffae, Sylvia atricapilla and Sylvia melanocephala), a lizard species (Gallotia galloti) and over a hundred insect species (mainly hymenopterans and coleopterans). Flying insects increased fruit set whereas small flower dwellers (mostly beetles) decreased both fruit and seed set. Vertebrates had a negligible effect on reproductive success. We conclude that although the floral resources provided by E. simplex may be important to some vertebrate species, these do not appear to contribute to increase fitness of the plant, which was more dependent upon flying insects for fruit and seed set. We additionally found that plant reproductive structures are heavily damaged by feral goats, which threaten the maintenance of this Canarian endemic species.
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 1 |
| 2013 | 1 |