Dynamic and spatial models of kelp forest of Macrocystis integrifolia and Lessonia trabeculata (SE Pacific) for assessment harvest scenarios: short-term responses

2010 ◽  
Vol 20 (5) ◽  
pp. 494-506 ◽  
Author(s):  
Marco Ortiz
Keyword(s):  
Kelp Forest ◽  
Spatial Models ◽  
Short Term ◽  
Lessonia Trabeculata ◽  
Macrocystis Integrifolia

The value of a broad temporal and spatial perspective in understanding dynamics of kelp forest ecosystems

2016 ◽  
Vol 67 (1) ◽  
pp. 14 ◽  
Author(s):  
Daniel C. Reed ◽  
Andrew R. Rassweiler ◽  
Robert J. Miller ◽  
Henry M. Page ◽  
Sally J. Holbrook
Keyword(s):  
Forest Ecosystems ◽  
Spatial Scales ◽  
Kelp Forest ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Short Term ◽  
Spatial Perspective ◽  
Ecological Responses ◽  
Temporal And Spatial

Many ecological processes play out over longer time scales and larger spatial scales than can be studied in a traditional 2–4-year grant cycle. Uncertainties in future funding hinder efforts to implement comprehensive research programs that integrate coupled time series observations of physical variables and ecological responses, manipulative experiments and synthetic analyses over the long term. Such research is essential for advancing our understanding of ecological responses associated with climate change, and the physical and biological processes that control them. This need is perhaps greatest for ecosystems that display highly dynamic and spatially complex patterns that are difficult to explain with short-term, small-scale studies. Such is the case for kelp forest ecosystems, which often show tremendous spatial and temporal variability in resource supply, consumer control and physical disturbance across spatial scales of metres to hundreds of kilometres and temporal scales of hours to decades. Here we present four examples from the Santa Barbara Coastal Long-term Ecological Research project that demonstrate the value of a broad temporal and spatial perspective in understanding the causes and ecological consequences of short-term local dynamics of giant kelp forests of California, USA.

Photosynthetic and light-independent carbon fixation in Macrocystis, Nereocystis, and some selected Pacific Laminariales

1979 ◽  
Vol 57 (8) ◽  
pp. 890-897 ◽  
Author(s):  
J. Willenbrink ◽  
B. P. Kremer ◽  
K. Schmitz ◽  
L. M. Srivastava
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Carbon Fixation ◽  
Soluble Fraction ◽  
Qualitative Difference ◽  
Calvin Cycle ◽  
Insoluble Fraction ◽  
Light Saturation ◽  
Short Term ◽  
Macrocystis Integrifolia ◽  
C Assimilation

The large kelp Macrocystis integrifolia and Nereocystis luetkeana off the coast of British Columbia have light saturation points at about 200 foot candles (1 foot candle = 10.76391 lx); however, photosynthetic rates remain unimpeded through mugh higher light intensities, up to 7000 foot candles. Short-term labelling experiments indicate that the Calvin cycle is operational in these plants, but, in addition, and particularly in the young growing parts, relatively high activities of phosphoenolpyruvate carboxykinase (PEP-CK)and correspondingly high rates of 14C fixation in the dark are observed. In older, mature parts, the activity of PEP-CK as well as the ability for light-independent 14C assimilation are lower. These observations are supported by data from a variety of other Pacific Laminariales. Pulse–chase experiments in the light and in the dark reveal characteristic differences between young and mature parts of the fronds: apart from qualitative difference in the soluble fraction of assimilates, the young parts show a significantly large proportion of radiocarbon confined to the ethanol-insoluble fraction.

Biosorption of Mercury(II) with Different Marine Algae

2009 ◽  
Vol 71-73 ◽  
pp. 585-588 ◽  
Author(s):  
Mariana Reategui ◽  
Holger Maldonado ◽  
M. Ly ◽  
Eric Guibal
Keyword(s):  
Marine Algae ◽  
Langmuir Equation ◽  
Order Equation ◽  
Lessonia Trabeculata ◽  
Salt Addition ◽  
Peruvian Coast ◽  
Grateloupia Doryphora ◽  
Macrocystis Integrifolia ◽  
Pseudo Second Order ◽  
Mercury Recovery

Five species of algae (Lessonia nigrescens Bory, Prionitis decipiens, Grateloupia doryphora, Lessonia trabeculata and Macrocystis integrifolia) collected from Peruvian coast have been tested for mercury recovery from synthetic solutions. Preliminary experiments showed that optimum sorption occurred at pH 6-7 and that Lessonia algae were the most efficient sorbents for Hg(II). The biomass was cross-linked with calcium chloride. Stabilized biosorbent showed sorption capacity as high as 267 mg g-1 at pH 6. The sorption isotherm was described by the Langmuir equation, while the pseudo-second order equation was used for modeling uptake kinetics. Salt addition strongly affected mercury sorption following the sequence: NaNO3 << Na2SO4 <<< NaCl.

Spatial and short-term variability of larval, post-larval and macrobenthic assemblages associated with subtidal kelp forest ecosystems in Central Chile

2017 ◽  
Vol 13 (10) ◽  
pp. 1041-1058 ◽  
Author(s):  
Sergio A. Carrasco ◽  
Loes Vandecasteele ◽  
Marcelo M. Rivadeneira ◽  
Miriam Fernández ◽  
Alejandro Pérez-Matus
Keyword(s):  
Forest Ecosystems ◽  
Kelp Forest ◽  
Short Term ◽  
Central Chile ◽  
Macrobenthic Assemblages ◽  
Short Term Variability

Transient population dynamics drive the spread of invasive wild pigs in North America

2021 ◽  
Author(s):  
Ryan S Miller ◽  
Michael Tabak ◽  
Christopher L Burdett ◽  
David W Wolfson
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
North America ◽  
Population Growth ◽  
Population Growth Rate ◽  
Spatial Models ◽  
Initial Population ◽  
Short Term ◽  
Wild Pigs ◽  
Transient Population

Invasion of nonindigenous species is considered one of the most urgent problems affecting native ecosystems and agricultural systems. Mechanistic models that account for short-term population dynamics can improve prediction because they incorporate differing demographic processes that link the environmental conditions of a spatial location explicitly with the invasion process. Yet short-term population dynamics are rarely accounted for in spatial models of invasive species spread. Accounting for transient population dynamics, we predict the population growth rate and establishment probability of wild pigs following introduction into any location in North America. We compared predicted population growth rate with observed geographic rates of spread and found significant relationships between the annual rate of spread and population growth rates. We used geospatial data on the distribution of mast producing tree species (a principle forage resource of wild pigs) and agricultural crops that can replace mast in their diets to predict population dynamics using transient population simulations. We simulated populations under different initial population sizes (i.e. number of introduced individuals, often termed propagule size) and for different amounts of time following introduction. By varying the initial population size and simulation time, we were able to identify areas in North America with high probability for establishment of wild pigs if introduced. Our findings can be used to inform surveillance and removal efforts to reduce the potential for establishment and spread of wild pigs.

scholarly journals The intensity of kelp harvesting shapes the population structure of the foundation species Lessonia trabeculata along the Chilean coastline

2021 ◽  
Vol 168 (5) ◽  
Author(s):  
Adam Gouraguine ◽  
Pippa Moore ◽  
Michael T. Burrows ◽  
Eliana Velasco ◽  
Luis Ariz ◽  
...  
Keyword(s):  
Kelp Forest ◽  
Foundation Species ◽  
Human Society ◽  
Goods And Services ◽  
Lessonia Trabeculata ◽  
Lack Of Information ◽  
Wide Range ◽  
Management Regimes ◽  
Wild Harvesting ◽  
Harvesting Intensity

AbstractKelp are foundation species that support high levels of biodiversity and, either directly or indirectly provide a wide range of ecological goods and services to human society. In recent decades, due to the high demand for kelp-derived products such as alginate, commercial wild harvesting has increased, leading to declines of kelp biomass in some regions. Chile accounts for 40% of the global kelp harvest, with the subtidal kelp, Lessonia trabeculata being one of the main target species. Currently, however, there is a lack of information on how different degrees of harvesting intensity, governed by distinct management regimes and their enforcement influences L. trabeculata populations. Here we examined the effect different management regimes, characterised by distinct levels of exploitation of kelp and kelp-associated fauna, have on L. trabeculata density and morphology along ~ 1600 km of the Chilean coastline. The findings demonstrated that harvesting intensity likely influences both L. trabeculata density and morphology. Juvenile density of L. trabeculata was five times higher in the most harvesting-affected areas, while kelp morphology values, including holdfast diameter, number of stipes and total length, were always higher in the less-intensively harvested areas. Our study suggests that different degrees of protection can influence density and morphology of subtidal  L. trabeculata populations, which in turn has important implications for the conservation of the kelp forest ecosystems and management of this important fishery.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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