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Pocillopora damicornis (Linnaeus) and Montipora verrucosa (Lamarck) were collected from Hawaiian reefs. In two experiments (September 1979-January 1980: ca. 4 mo; August-October 1980; ca. 2 mo), these reef corals were grown under sunlight passed through filters producing light fields of similar quantum flux but different spectral composition. In vitro cultures of symbiotic zooxanthellae (Symbiodinium microadriaticum Freudenthal) from M. verrucosa were cultured under similar conditions for 15 d. Blue or white light promoted more coral skeletal growth than green or red light. In both coral species, blue light increased the total amount of chlorophyll a of the coral-zooxanthellae association. In the perforate species, M. verrucosa, the pigment concentration was elevated by an increase in the density of zooxanthellae, but the pigment concentrations per algal cell remained unchanged; in the non-perforate species, P. damicornis, it appears that pigment concentration was elevated by an increase in pigment per algal cell, and not by an increase in density of zooxanthellae. The sunloving reef-flat coral P. damicornis did not grow as rapidly as the shade-species M. verrucosa at the low quantum flux (about 10% sunlight) provided by the experimental treatments. The in vitro cultures of zooxanthellae from M. verrucosa exhibited growth rates in light of altered spectral quality that correlated with the responses of the host coral species: blue and white light supported significantly greater growth than green light, and red light resulted in the lowest growth rate.Contribution No. 678 of the Hawaii Institute of Marine Biology 相似文献
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David W. York Benjamin C. Dysart Lawrence W. Gahan 《Journal of the American Water Resources Association》1977,13(1):13-24
ABSTRACT: This paper presents a mathematical model of multiple-use in natural areas. The model represents a unified system for the assessment of cases where some form of development is proposed for relatively natural areas. The focus of the model system is a benefit-cost analysis. Provisions for the full consideration of easily measured monetary costs and benefits as well as semitangible benefits accruing from environment-related activities such as outdoor recreation are contained in the model. Means for incorporating desirability as a measure of aesthetics, uniqueness, and environmental quality into the evaluation are provided. Serveral types of constraints have been imposed on the system to increase model realism. A family of compatibility constraints was designed to limit inter-use conflicts arising from incompatible activities. A form of the gradient optimization algorithm was utilized to facilitate the evaluation. The model system has application in a wide range of problems frequently encountered in environmental planning and assessment as well as natural resources management. 相似文献
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Peter I. Macreadie Paul H. York Craig D. H. Sherman Michael J. Keough D. Jeff Ross Aurora M. Ricart Timothy M. Smith 《Marine Biology》2014,161(12):2939-2944
Seagrass meadows are among the most efficient and long-term carbon sinks on earth, but disturbances could threaten this capacity, so understanding the impacts of disturbance on carbon stored within seagrass meadows—‘blue carbon’—is of prime importance. To date, there have been no published studies on the impacts of seagrass loss on ‘blue carbon’ stocks. We experimentally created several kinds of small-scale disturbances, representative of common grazer and boating impacts, within seagrass (Zostera nigracaulis) meadows in Port Phillip Bay (Australia) and measured the impacts on sediment organic carbon stocks (‘C org’, and other geochemical variables—%N, δ13C, δ15N). Disturbance had no detectable effect on C org levels within seagrass sediments, even for high-intensity disturbance treatments, which remained bare (i.e. no seagrass recovery) for 2 years after the disturbance. These findings challenge the widely held assumption that disturbance and concomitant loss of seagrass habitat cause release of carbon, at least for small-scale disturbances. We suggest that larger (e.g. meadow scale) disturbances may be required to trigger losses of ‘blue carbon’ from seagrass meadows. 相似文献
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Cochrane Logan Cundill Georgina Ludi Eva New Mark Nicholls Robert J. Wester Philippus Cantin Bernard Murali Kallur Subrammanyam Leone Michele Kituyi Evans Landry Marie-Eve 《Regional Environmental Change》2017,17(5):1553-1561
Regional Environmental Change - The reality of global climate change demands novel approaches to science that are reflective of the scales at which changes are likely to occur, and of the new forms... 相似文献
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An Empirical Evaluation of Private Landowner Participation in Voluntary Forest Conservation Programs
The use of voluntary programs targeting resource conservation on private land has become increasingly prevalent in environmental
policy. Voluntary programs potentially offer significant benefits over regulatory and market-based approaches. This article
examines the factors affecting landowner participation in voluntary forest conservation programs using a combination of parcel-level
GIS and remotely sensed data and semi-structured interviews of landowners in Monroe County, Indiana. A logistic regression
model is applied to determine the probability of participation based on landowner education, membership in other non-forest
voluntary programs, dominant land use activity, parcel size, distance from urban center, land resource portfolios, and forest
cover. Both land use activity and the spatial configuration of a landholder’s resource portfolio are found to be statistically
significant with important implications for the design and implementation of voluntary programs.
相似文献
Derek KauneckisEmail: |
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Climate change impact assessment is subject to a range of uncertainties due to both incomplete and unknowable knowledge. This
paper presents an approach to quantifying some of these uncertainties within a probabilistic framework. A hierarchical impact
model is developed that addresses uncertainty about future greenhouse gas emissions, the climate sensitivity, and limitations
and unpredictability in general circulation models. The hierarchical model is used in Bayesian Monte-Carlo simulations to
define posterior probability distributions for changes in seasonal-mean temperature and precipitation over the United Kingdom
that are conditional on prior distributions for the model parameters. The application of this approach to an impact model
is demonstrated using a hydrological example.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Stefano B. Longo Brett Clark Richard York Andrew K. Jorgenson 《Conservation biology》2019,33(4):832-841
In modern aquaculture, animal-production technology is used to increase aquatic food sources. Such controlled rearing of seafood can, in principle, shift the pressure off wild stocks and aquatic ecosystems by reducing fishing activities, which may advance marine conservation goals. We examined resource displacement—the reduced consumption of a resource due to its replacement with a more environmentally benign substitute—in fisheries. We employed panel regression techniques in an analysis of time-series data from 1970 through 2014 to assess the extent to which aquaculture production displaced fisheries captures for all nations for which data were available. We estimated 9 models to assess whether aquaculture production suppresses captures once other factors related to demand have been controlled for. Only 1 model predicted significant suppression of fisheries captures associated with aquaculture systems within nations over time. These results suggest that global aquaculture production does not substantially displace fisheries capture; instead, aquaculture production largely supplements fisheries capture. 相似文献
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