Potential for reintroduction of lake sturgeon in five northern Lake Michigan tributaries: a habitat suitability perspective     

Daniel J. Daugherty  Trent M. Sutton  Robert F. Elliott 《水产资源保护:海洋与淡水生态系统》2008,18(5):692-702

• 1. Conservation and rehabilitation efforts for lake sturgeon Acipenser fulvescens throughout the Great Lakes include the re‐establishment of self‐sustaining stocks in systems where they have been extirpated.
• 2. Information on the suitability of potential lake sturgeon habitat in tributaries is important for determining their capacity to support lake sturgeon stocking and to develop system‐specific rehabilitation strategies.
• 3. Geo‐referenced habitat information characterizing substrate composition, water depth, and stream gradient were applied to a life‐stage specific lake sturgeon habitat suitability index in a geographic information system to produce spatially explicit models of life‐stage specific habitat characteristics in five northern Lake Michigan tributaries from which lake sturgeon have been extirpated.
• 4. Habitat models indicated that high quality lake sturgeon spawning and staging habitat comprised 0 to 23% and 0 to 9% of the available habitat, respectively, whereas high quality juvenile lake sturgeon habitat was relatively ubiquitous throughout each river and comprised 39 to 99%.
• 5. Comparison of these data to lake sturgeon habitat availability in Lake Michigan tributaries currently supporting populations indicated that spawning and staging habitats may limit the ability of these systems to support spawning. Efforts to re‐establish lake sturgeon populations in these systems should consider the creation of spawning and staging habitat to increase reproductive and recruitment potential prior to the initiation of stocking efforts.

Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Mutualism between euryhaline tilapia Sarotherodon melanotheron heudelotii and Chlorella sp.—Implications for nano-algal production in warmwater phytoplankton-based recirculating systems     

Sylvain Gilles  Grard Lacroix  Daniel Corbin  Ngansoumana B  Carla Ibaez Luna  Jacob Nandjui  Allassane Ouattara  Oussni Oudraogo  Xavier Lazzaro 《Aquacultural Engineering》2008,39(2-3):113-121

The West-African euryhaline tilapia, Sarotherodon melanotheron heudelotii shift from visually feeding on zooplankton when juveniles to mostly filter feeding on phytoplankton when adults. When reared using an appropriate ration in intensive aquaculture systems, S. m. heudelotii also consume algal-based detritus, and contribute to sediment mineralization, clean up their environment, and ultimately stimulate and sustain algal growth. We analysed such practical advantages for phytoplankton-based recirculating systems, using S. m. heudelotii and Chlorella sp. as biological material originating from the prototype of such a system operated in Senegal. We performed a 24-h factorial design experiment in 36 tubs, cross-classifying three levels of S. m. heudelotii (fishless control, unfed fish, and fed fish) with four levels of Chlorella initial density.Chlorella overall mean density increased significantly from fishless, to unfed fish, and fed fish treatments, and with Chlorella initial density. S. m. heudelotii did not alter nitrogen nor phosphorus concentrations, only affected by algal initial densities. Most ammonia excreted by fish was probably uptaken by Chlorella. Bacteria-mediated diurnal nitrification was possibly an alternative ammonium loss mechanism at highest oxygen concentrations. Algae were not limited by nitrogen or phosphorus but most likely by low dissolved organic carbon availability. Chlorella differential responses with fed vs. unfed Sarotherodon suggest that CO₂ supplied by heterotrophic S. m. heudelotii respiration played a key role. Observed Chlorella growth rates were similar to the highest rates obtained in algal mass cultures, enriched with CO₂, nitrate and phosphate, under artificial lighting.Our results suggest the existence of a Sarotherodon-Chlorella mutualism in our systems, where S. m. heudelotii provide CO₂, the major limiting factor of Chlorella growth, whereas Chlorella oxygenate and detoxify the water media from ammonia, promoting S. m. heudelotii production. This mutualism could be used to optimize photosynthetic suspended-growth aquaculture systems, particularly in the Tropics where light is abundant and temperature is continuously high.  相似文献   

Path analysis of spatial predictors of front-yard landscape in an anthropogenic environment   总被引：4，自引：0，他引：4  

Zmyslony  Jean  Gagnon  Daniel 《Landscape Ecology》2000,15(4):357-371

Contagious spatial patterns were shown to exist in the landscape of front-yards in street sections of Hochelaga-Maisonneuve, Montréal. Neighbour mimicry was hypothesized as the mechanism behind this pattern (Zmyslony and Gagnon 1998). To assess the role of spatial environmental factors in structuring this pattern, we carried out a path analysis on the front-yard landscape with five spatial factors: relative distance, street side, width, depth and type of front-yard. We removed all non-significant factors from our model with simple Mantel tests and untangled the common spatial component from the relationship between spatial factors and front-yard landscape with partial Mantel tests. We then used path analysis to evaluate the relative importance of all significant spatial factors in structuring front-yard landscape and to determine the r ² (% of landscape variation explained by spatial factors). Results showed that (1) among all spatial environmental factors, distance (proximity) remained the best predictor of front-yard vegetation – distance alone explained an average of 20% of the landscape variation of a street section, (2) depth, width and type of front-yard also structured the front-yard landscape independently of distance, (3) front-yard landscape expresses greater similarity within the same side of a street section, and (4) in two street sections of Hochelaga-Maisonneuve, spatial factors predicted over 40% of the landscape variation. This suggests (1) that landscape contagion exists also in highly humanized environments and (2) that the mimicry phenomenon was induced not only by proximity, but also by similar environmental conditions in same side street sections and whole street sections. Finally, we suggest that street sections are a very useful and appropriate unit of analysis of urban ecosystems.  相似文献   

Using operating area size and adjacency constraints to mitigate the effects of harvesting activities on boreal caribou habitat     

Guillaume Cyr  Frédéric Raulier  Daniel Fortin  David Pothier 《Landscape Ecology》2017,32(2):377-395

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New Approaches to Modeling Methyl Jasmonate Effects on Pomegranate Quality during Postharvest Storage     

Mohammad Sayyari  Daniel Valero 《International Journal of Fruit Science》2017,17(4):374-390

Adaptive neuro fuzzy inference system (ANFIS) and genetic algorithm–artificial neural network (GA-ANN) models were used to predict the effect of methyl jasmonate (at three levels 0, 0.01, and 0.1 mM) and storage time (0, 14, 28, 42, 56, 70, and 84 days) on quality parameters and physiological changes of pomegranate fruits during storage. Methyl jasmonate reduced chilling injury and improved quality characteristics of pomegranates during postharvest storage. The GA-ANN and ANFIS were fed with two inputs of methyl jasmonate and storage time. The results showed that GA-ANN predictions agreed with experimental data and the GA-ANN with 14 neurons in one hidden layer can predict physiological changes and quality parameters of pomegranate (weight loss, pH, chilling injury index, ion leakage, ethylene, respiration, polyphenols, anthocyanins, and total antioxidant activity) with correlation coefficients equal to 0.87. The ANFIS model was trained by a hybrid method and agreement between experimental data and ANFIS predictions was significant (r = 0.90).  相似文献   

Allelic composition and associated quality traits of the <Emphasis Type="Italic">Glu-1</Emphasis> and <Emphasis Type="Italic">Glu-3</Emphasis> loci in selected modern Ethiopian durum wheat varieties     

Daniel Hailegiorgis  Chong Ae Lee  Song Joong Yun 《Journal of Crop Science and Biotechnology》2017,20(5):387-392

Gluten protein determines the processing quality of both durum wheat and bread wheat. The glutenin subunits compositions and associated quality traits of 20 Ethiopian durum wheat varieties were systematically analyzed using SDS-PAGE and Payne numbers. A total of 16 glutenin patterns were identified. At the Glu-A1 locus, all varieties scored the null allele. The predominant glutenin alleles at the Glu-B1 locus were Glu-B1b (7+8) and Glu-B1e (20). In Glu-3, the most abundant glutenin subunits were Glu-A3a and Glu-B3c. Based on the Payne scores, the varieties Yerer, Ginchi, Candate, and Foka were identified to have allelic composition suitable for pasta making. The cluster analysis using agglomerative hierarchical clustering (AHC) method classified the varieties into four similarity classes. Based on the findings of this experiment, suggestions were made for allelic composition improvement through introgression of superior alleles from known Glu-1 and Glu-3 sources.  相似文献   

Plant somatic mutations in nature conferring insect and herbicide resistance     

Daniel Simberloff  Christy Leppanen 《Pest management science》2019,75(1):14-17

Because of the role of the meristem in plant growth and reproduction, somatic mutations in plants have long been suspected of conferring herbivore and pathogen resistance on individual plants and, in the case of trees, individual branches within single plants. A few instances of resistance to phytophagous insects owing to somatic mutations have been reported in the literature. More recently, a striking example has demonstrated how somatic mutations confer resistance to an herbicide on an invasive plant, Hydrilla verticillata. The array of new methods for manipulating genomes (e.g., gene‐editing) plus existing examples of somatic mutation‐associated resistance suggest that such mutations might be useful in silviculture, agriculture, and horticulture. Answering several general questions about somatic mutations in plants would facilitate such applications: Why are so few examples reported? Do other cases exist but go undetected for want of adequate attention or methods? Under what circumstances do somatic mutations enter gametophytes? © 2018 Society of Chemical Industry  相似文献   

Association of zein nanoparticles with botanical compounds for effective pest control systems     

Jhones L de Oliveira  Estefnia V R Campos  Taís Germano‐Costa  Renata Lima  Jaqueline Franciosi Della Vechia  Sidneia Terezinha Soares  Daniel Junior de Andrade  Kelly Cristina Gonalves  Joacir do Nascimento  Ricardo Antonio Polanczyk  Leonardo Fernandes Fraceto 《Pest management science》2019,75(7):1855-1865

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Ecology and management of earthworm casting on sports turf     

Paige E Boyle  Michael D Richardson  Mary C Savin  Douglas E Karcher  Daniel A Potter 《Pest management science》2019,75(8):2071-2078

Earthworm activity is beneficial in most natural and agricultural systems, but excessive earthworm casting is a problem on sports fields worldwide. Expulsion of soil‐rich earthworm fecal matter, or casts, as mounds of soil on the turf canopy can muddy the surface, reduce photosynthesis, and lead to thinning, weed invasion and surface softening. Casts affect ball roll on sports fields, cause fouling of maintenance equipment, and dull mower blades. Build‐up of cast material on reel mower units can affect height and quality of cut. Casting activity is dependent on environmental conditions such as soil texture, temperature, moisture, pH, and organic matter. Response to environmental conditions varies by species. Management options are limited, because no pesticides are specifically labeled for earthworm control at this time, and cultural control methods such as soil modification, turfgrass clipping removal, and sand topdressing have limited and inconsistent efficacy. Products containing plant‐derived saponins and irritants show promise for earthworm management. Pest management practices to mitigate excessive earthworm casting will likely need to be species‐specific, but limited knowledge of earthworm identification by end‐users further inhibits the efficacy of control measures. © 2019 Society of Chemical Industry  相似文献   

The ecosystem services concept: a new Esperanto to facilitate participatory planning processes?     

Spyra  Marcin  Kleemann  Janina  Cetin  Nuket Ipek  Vázquez Navarrete  Cesar Jesús  Albert  Christian  Palacios-Agundez  Igone  Ametzaga-Arregi  Ibone  La Rosa  Daniele  Rozas-Vásquez  Daniel  Adem Esmail  Blal  Picchi  Paolo  Geneletti  Davide  König  Hannes J.  Koo  HongMi  Kopperoinen  Leena  Fürst  Christine 《Landscape Ecology》2019,34(7):1715-1735

Landscape Ecology - Several case studies investigated the role of ecosystem services in participatory planning processes. However, no systematic study exists that cuts across a large number of...  相似文献