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We estimated the population sizes of the three species of columnar cacti that grow on the island of Curaçao using ground and aerial transects, and we examined the island's carrying capacity for two species of nectar-feeding bats that depend on nectar from the flowers of these cacti. We calculated carrying capacity based on the daily availability of mature flowers between January and December 1993 and the field energy requirements of bats as estimated from an equation for eutherian mammals (low estimate) and one for passerine birds (high estimate) based on body mass. Additional energy requirements of pregnancy and lactation were taken into account. We estimated that 461,172 columnar cacti were present on Curaçao (38% Subpilocereus repandus , 51% Stenocereus griseus , and 11% Pilosocereus lanuginosus ). May through September are the critical months when bats rely most heavily on cactus for food. July 1993 was a bottleneck with the smallest number of mature flowers per day. July and August were months of greatest energy demand because females were lactating. We estimate that the carrying capacity for Glossophaga longirostris in July, when the bat ( Leptonycteris curasoae ) population was 900, was near 1200, an estimate that fits the observed population size of nectar-feeding bats on the island. We suggest that the extensive removal of native vegetation occurring on Curaçao be strictly regulated because further destruction of the cacti will result in a decrease and potential loss of the already low populations of nectar-feeding bats. 相似文献
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Reyer Christopher P.O Otto Ilona M. Adams Sophie Albrecht Torsten Baarsch Florent Cartsburg Matti Coumou Dim Eden Alexander Ludi Eva Marcus Rachel Mengel Matthias Mosello Beatrice Robinson Alexander Schleussner Carl-Friedrich Serdeczny Olivia Stagl Judith 《Regional Environmental Change》2017,17(6):1639-1650
Regional Environmental Change - This paper synthesizes what is known about the physical and biophysical impacts of climate change and their consequences for societies and development under... 相似文献
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Production of biofuels from microalgae 总被引:1,自引:1,他引:0
Sophie Fon Sing Andreas Isdepsky Michael A. Borowitzka Navid Reza Moheimani 《Mitigation and Adaptation Strategies for Global Change》2013,18(1):47-72
The production of biofuels from microalgae, especially biodiesel, has become a topic of great interest in recent years. However, many of the published papers do not consider the question of scale up and the feasibility of the various processes to be operated at the very large scale required if algal biofuels are to make a meaningful contribution to renewable fuels. All the steps in the process must also be very low cost. This paper discusses the unit processes required for algal biofuels production (i.e., growing the algae, harvesting, dewatering, extraction and conversion to biofuel) and their scalability. In many cases, especially in the lipid extraction step, little is known as yet as to the scalability and economic feasibility of the various processes proposed. We also highlight the key engineering and biological issues which must be resolved for the production of biofuels from microalgae to become an economic reality. 相似文献