61 research outputs found
Exploring the predation of UK bumblebees (Apidae, Bombus spp.) by the invasive pitcher plant Sarracenia purpurea: examining the effects of annual variation, seasonal variation, plant density and bumblebee gender
Invasive carnivorous plant species can impact the native invertebrate communities on which they prey. This article explores the predation of native UK bumblebees (Bombus spp.) by the invasive pitcher plant species Sarracenia purpurea and discusses the potential effect of S. purpurea on native bumblebees. Specifically, it evaluates whether the extent to which bumblebees are captured varies (i) over successive years, (ii) across June and July, (iii) with density of distribution of pitchers or (iv) with bumblebee gender. Pitcher contents were examined from an established population of Sarracenia purpurea growing in Dorset, UK. Results show that the total extent to which bumblebees were captured differed over the years 2012â2014 inclusive. A 1-year study in 2013 showed that more bumblebees were caught in July than in June and more bumblebees were captured when pitchers grew at high density. Results from 2013 also showed that more pitchers caught more than one bumblebee than would be expected based on a normal probability distribution and that this phenomenon affects female and male bumblebees equally. We discuss possible reasons for these results including that the bumblebees may be using S. purpurea as a resource. Further work is required to establish the exact underpinning mechanisms and the relative roles of plant and bumblebee behaviour within the relationship. Such interaction complexity may have consequences for consideration in invasive carnivorous plant management
In Situ Enzyme Activity in the Dissolved and Particulate Fraction of the Fluid from Four Pitcher Plant Species of the Genus Nepenthes
The genus Nepenthes, a carnivorous plant, has a pitcher to trap insects and digest them in the contained fluid to gain nutrient. A distinctive character of the pitcher fluid is the digestive enzyme activity that may be derived from plants and dwelling microbes. However, little is known about in situ digestive enzymes in the fluid. Here we examined the pitcher fluid from four species of Nepenthes. High bacterial density was observed within the fluids, ranging from 7Ă106 to 2.2Ă108 cells mlâ1. We measured the activity of three common enzymes in the fluid: acid phosphatases, ÎČ-d-glucosidases, and ÎČ-d-glucosaminidases. All the tested enzymes detected in the liquid of all the pitcher species showed activity that considerably exceeded that observed in aquatic environments such as freshwater, seawater, and sediment. Our results indicate that high enzyme activity within a pitcher could assist in the rapid decomposition of prey to maximize efficient nutrient use. In addition, we filtered the fluid to distinguish between dissolved enzyme activity and particle-bound activity. As a result, filtration treatment significantly decreased the activity in all enzymes, while pH value and Nepenthes species did not affect the enzyme activity. It suggested that enzymes bound to bacteria and other organic particles also would significantly contribute to the total enzyme activity of the fluid. Since organic particles are themselves usually colonized by attached and highly active bacteria, it is possible that microbe-derived enzymes also play an important role in nutrient recycling within the fluid and affect the metabolism of the Nepenthes pitcher plant
Quite a few reasons for calling carnivores "the most wonderful plants in the world"
A plant is considered carnivorous if it receives any noticeable benefit from catching small animals. The morphological and physiological adaptations to carnivorous existence is most complex in plants, thanks to which carnivorous plants have been cited by Darwin as âthe most wonderful plants in the worldâ. When considering the range of these adaptations, one realizes that the carnivory is a result of a multitude of different features.
Scope: This review discusses a selection of relevant articles, culled from a wide array of research topics on plant carnivory, and focuses in particular on physiological processes associated with active trapping and digestion of prey. Carnivory offers the plants special advantages in habitats where nutrient supply is scarce. Counterbalancing costs are the investments in synthesis and the maintenance of trapping organs and hydrolysing enzymes. With the progress in genetic, molecular and microscopic techniques, we are well on the way to a full appreciation of various aspects of plant carnivory.
Conclusions: Sufficiently complex to be of scientific interest and finite enough to allow conclusive appraisal, carnivorous plants can be viewed as unique models for the examination of rapid organ movements, plant excitability, enzyme secretion, nutrient absorption, food-web relationships, phylogenetic and intergeneric relationships or structural and mineral investment in carnivory
Rapid fluctuations in mid-latitude siliceous plankton production during the Middle Eocene Climatic Optimum (ODP Site 1051, western North Atlantic)
Investigations on the ecology of the marine centric diatom Paralia sulcata at Helgoland Roads, North Sea, Germany. PhD thesis.
Andrew T. Chamberlain, Demography in Archaeology. (Cambridge: Cambridge University Press [Cambridge Manuals in Archaeology], 2006, 256 pp., 36 line diagrams, pbk, ISBN-13 9780521596510, ISBN-10 0521596513)
Effects of salinity, temperature and nutrients on growth, cellular characteristics and yessotoxin production of Protoceratium reticulatum
Protoceratium reticulatum as a producer of yessotoxin (YTX) and its analogues is common in several coastal environments. The YTX-producing strain of P. reticulatum, isolated from the German Bight (North Sea), was analysed to study toxin production under various autecological conditions. Experiments were carried out to investigate the influence of N/P ratio (2.44 (1/10 N), 24.36 (f/2) and 243.65 (1/10 P)), temperature (15 and 20 Â°C), salinity (5, 10, 15, 20, 25 and 30) and growth phase on YTX formation, cell size and chlorophyll a concentration. P. reticulatum showed the highest growth at 15 Â°C and higher salinities (25 and 30). In particular, higher temperature led to a reduced growth. The total YTX concentrations were higher at lower temperature. However, a clear correlation between salinity and YTX production was not observed at lower temperature. Furthermore, 1/10 P and f/2 cultures exhibited the highest cell quota of YTX at the end of the stationary phase; a dramatic effect occurred at 15 Â°C in 1/10 P media, when the toxicity increased to ten fold higher values. Slight variations of the composition of the YTX analogues under nutrient limitation were observable. In addition, the results indicate that N-limitation cause a lower cell size, whereas P-limitation leads to a higher cell size; an influence of the salinity on cell size was also observable
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