The Barren Grounds by David A. Robertson

2020 ◽  
Vol 74 (1) ◽  
pp. 46-46
Author(s):  
Kiri Palm
Keyword(s):  
Barren Grounds

Geographic and environmental factors affecting the distribution of kelp beds and barren grounds and changes in biota associated with kelp reduction at sites along the Norwegian coast

1997 ◽  
Vol 54 (12) ◽  
pp. 2872-2887 ◽  
Author(s):  
Knut Sivertsen
Keyword(s):  
Environmental Factors ◽  
Sea Urchins ◽  
Strongylocentrotus Droebachiensis ◽  
The Arctic ◽  
Laminaria Hyperborea ◽  
Factors Affecting ◽  
Kelp Beds ◽  
The Mean ◽  
Transition Areas ◽  
Barren Grounds

Sites at 244 locations along the west and north Norwegian coasts were investigated to evaluate whether kelp (Laminaria hyperborea) beds had been overgrazed by the sea urchins Strongylocentrotus droebachiensis and Echinus esculentus in the years 1981-1992. Barren ground communities were found in sheltered and moderately wave-exposed areas mainly in the inner and middle archipelago from Nordmøre (63°N) northwards. Densities of large-sized (adult and intermediate) L. hyperborea were 20.7 individuals ·m-2 in kelp beds and 9.7 individuals ·m-2 in transition areas. Juvenile Laminaria spp. were present at densities of 23.9 individuals ·m-2 in kelp beds, 3.6 individuals ·m-2 in transition areas, 0.0 individuals ·m-2 in barren grounds, and 59.1 individuals ·m-2 in kelp-harvested locations. Both the densities and the mean size of S. droebachiensis in barren grounds decreased northwards. The mean densities were 52.2 and 26.1 individuals ·m-2 for the areas south and north of the Arctic Circle, respectively. Multivariate analysis (CANOCO) showed that seven ``environmental'' factors (i.e., kelp depth gradient, distance (latitude), time of sampling, nematode infection in S. droebachiensis, wave exposure, coastal gradient, and substratum) contributed significantly to variability in the distribution of kelp beds and barren grounds. Species in hard-bottom communities in shallow waters could be divided into three distinct BIOTA.

scholarly journals Impairment of microbial and meiofaunal ecosystem functions linked to algal forest loss

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Silvia Bianchelli ◽  
Roberto Danovaro
Keyword(s):  
Habitat Loss ◽  
Ecosystem Functioning ◽  
Negative Impact ◽  
Ecosystem Functions ◽  
Marine Biodiversity ◽  
Forest Loss ◽  
Higher Taxa ◽  
Vulnerable Habitats ◽  
Nematode Biodiversity ◽  
Barren Grounds

AbstractHabitat loss is jeopardizing marine biodiversity. In the Mediterranean Sea, the algal forests of Cystoseira spp. form one of the most complex, productive and vulnerable shallow-water habitats. These forests are rapidly regressing with negative impact on the associated biodiversity, and potential consequences in terms of ecosystem functioning. Here, by comparing healthy Cystoseira forests and barren grounds (i.e., habitats where the macroalgal forests disappeared), we assessed the effects of habitat loss on meiofaunal and nematode biodiversity, and on some ecosystem functions (here measured in terms of prokaryotic and meiofaunal biomass). Overall, our results suggest that the loss of Cystoseira forests and the consequent barren formation is associated with the loss of meiofaunal higher taxa and a decrease of nematode biodiversity, leading to the collapse of the microbial and meiofaunal variables of ecosystem functions. We conclude that, given the very limited resilience of these ecosystems, active restoration of these vulnerable habitats is needed, in order to recover their biodiversity, ecosystem functions and associated services.

Distribution and abundance of Rhynchocinetes typus (Crustacea: Decapoda), in different benthic community structures in northern Chile

2003 ◽  
Vol 83 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Luis M. Caillaux ◽  
Wolfgang B. Stotz
Keyword(s):  
Benthic Community ◽  
Subtidal Zone ◽  
Suspension Feeding ◽  
North Central ◽  
The North ◽  
Lessonia Trabeculata ◽  
Different Types ◽  
Community Types ◽  
Shrimp Abundance ◽  
Barren Grounds

An evaluation was carried out on the distribution and abundance of the rock shrimp Rhynchocinetes typus in the inshore subtidal zone on the north-central coast of Chile. A number of different benthic community types occur in the region which have different degrees of spatial complexity provided by the primary substratum and by the biotic communities colonizing the substratum. Shrimp abundance was estimated in five different community types including shallow and deep ‘barren grounds’, low encrusting communities, erect suspension feeding associations, and kelp beds of Lessonia trabeculata. The abundance of shrimp was determined on three different types of primary substratum (stones, boulders, rock mass) within each community. Rhynchocinetes typus occurred in all the communities studied, showing the highest abundance on the deep barren grounds and lowest abundance on the shallow barren grounds. The shrimp was found to prefer the stony areas, as these offered the greatest degree of refuge. The abundance of predators was not significantly different among the different communities. However, a decline of abundance of predators was apparent over the deep barren grounds.

The decline, response to fire, status and management of the Eastern Bristlebird

1997 ◽  
Vol 3 (3) ◽  
pp. 235 ◽  
Author(s):  
Jack Baker
Keyword(s):  
Nature Reserve ◽  
New South ◽  
Population Monitoring ◽  
Average Density ◽  
Disjunct Distribution ◽  
Habitat Manipulation ◽  
Southeastern Australia ◽  
South Wales ◽  
Western Victoria ◽  
Barren Grounds

The Eastern Bristlebird Dasyornis brachypterus is a threatened passerine, endemic to southeastern Australia. It is a cryptic, ground dwelling, semi-flightless inhabitant of dense, fire-prone vegetation and is usually only detected by its calls. The disjunct distribution suggests that they were once more numerous and their population continuous from southern Queensland to western Victoria. Their decline has been documented in historic and recent times. Habitat loss, nest desertion and fire have been implicated in the decline and extinction of local populations. Strongholds for the species are Barren Grounds Nature Reserve and Bherwerre Peninsula, 100 and 150 km south of Sydney respectively. At Barren Grounds, in the absence of recent fire, there were significant increases in the population between 1992 and 1996. There was a trend of increasing Eastern Bristlebird density with increasing fire-age of habitat and average density plateauing at two birds per 5 ha, 10 years after fire. At Nadgee, a coastal Nature Reserve on the New South Wales/Victorian border, the population appears to be recovering very slowly from severe wildfires in 1972 and 1980. At the beginning of 1996 there were less than 2 000 individual Eastern Bristlebirds occupying an area of approximately 100 km2. For the management of Eastern Bristlebirds, habitat manipulation using prescribed fire should not be undertaken unless site-specific population monitoring data demonstrate that it would be beneficial. Concentrations of Eastern Bristlebirds and potential fire refuges should be protected from unplanned fire. For prescription burns, potential escape routes need to be planned for Eastern Bristlebirds. The threatened status should be changed from Vulnerable to Endangered.

The Moffatt Archaeological Collection from the Dubawnt Country, Canada

1959 ◽  
Vol 24 (4Part1) ◽  
pp. 412-422
Author(s):  
Elmer Harp
Keyword(s):  
New York ◽  
New York City ◽  
York City ◽  
Sao Paulo ◽  
São Paulo ◽  
Barren Grounds

On July 3, 1955, six men in three canoes shoved out into Black Lake, Saskatchewan, and began a long journey northward toward the great Barren Grounds. The party consisted of Peter Franck of Woodside, California; George Grinnell of New York City; J. Edward Lanouette of São Paulo, Brazil; Bruce LeFavour of Amsterdam, New York; Fred Pessl, Jr., of Grosse Pointe Woods, Michigan; and the leader and organizer of the expedition, Arthur R. Moffatt of Norwich, Vermont.

High-Levels of Outcrossing in Populations of Banksia spinulosa R.Br. and Banksia paludosa Smith

1988 ◽  
Vol 36 (2) ◽  
pp. 217 ◽  
Author(s):  
SM Carthew ◽  
DJ Ayre ◽  
RJ Whelan
Keyword(s):  
Nature Reserve ◽  
Single Locus ◽  
Barren Grounds

Rates of outcrossing were measured for two species of Banksia at Barren Grounds Nature Reserve, near Robertson, N.S.W. For B. spinulosa in a woodland area, both single-locus and multi-locus estimates of outcrossing approached the levels predicted for panmixia. A single-locus estimate for B. paludosa cohabiting the same site and a nearby heathland site gave similarly high estimates of outcrossing.

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