scholarly journals Changes in the distribution and abundance of Carex ericetorum in Britain since the 1970s

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Kevin Walker ◽  
Peter Stroh
Keyword(s):  
Nitrogen Deposition ◽  
Agricultural Intensification ◽  
Vegetation Management ◽  
Calcareous Grassland ◽  
Festuca Ovina ◽  
East Anglia ◽  
Limestone Grassland ◽  
Population Sizes ◽  
Winter Grazing ◽  
Autumn And Winter

British populations of Carex ericetorum Poll. (Rare Spring Sedge) were visited between 2008 and 2015 to assess size, habitats, associated vegetation, management, threats and changes in abundance since the 1970s. C. ericetorum was relocated at 40 of the 64 sites visited, mainly in northwest England (24 sites) and East Anglia (nine sites); most populations that couldn’t be relocated were in southern and eastern England. Population sizes were usually small (<100 individuals) and had remained relatively stable or had increased in size since the 1970s. In southern and eastern England, C. ericetorum was restricted to species-rich calcareous grassland overlying chalk or limestone dominated by Festuca ovina and Bromopsis erecta. In northwest England, it was confined to limestone grassland dominated by Sesleria caerulea. Ideal management for C. ericetorum comprised autumn and winter grazing to maintain a short sward (<6 cm), although it had persisted in the absence of grazing where the growth of dominants was restricted by exposure and/or soil infertility. The main threat to its survival is now a lack of grazing leading to increased competition with tall grasses, although agricultural intensification had caused losses in the lowlands. Nitrogen deposition is also likely to have compounded these threats on some sites. Its survival on many sites will require the maintenance or reinstatement of grazing.

Differences in the swimming behaviour of the amphipod Corophium volutator from different populations

1990 ◽  
Vol 70 (1) ◽  
pp. 143-148 ◽  
Author(s):  
R.G. Hughes ◽  
I. M. Horsfall
Keyword(s):  
East Coast ◽  
High Water ◽  
Flood Tide ◽  
Swimming Behaviour ◽  
Corophium Volutator ◽  
East Anglia ◽  
Laboratory Conditions ◽  
Different Populations ◽  
Autumn And Winter

The swimming behaviour of Corophium volutator from Wales and East Anglia was investigated to establish whether differences apparent from two previous studies are real or artefacts of the different techniques used. Swimming C. volutator were caught in a Welsh estuary in the summer, but only rarely in the autumn and winter, and in both daylight and darkness. In simulated tidal conditions in the laboratory C. volutator from two sites in East Anglia never swam, while those from Wales swam whenever the substratum was immersed, in daylight and darkness, mostly on the ebb tide and in winter. The unnatural swimming in winter may have been stimulated by laboratory conditions, but the East Anglian amphipods were not so affected. The tidal swimming rhythm is different to east coast C. volutator which only swim at night. This difference may be related to the time of spring tides, when most swimming occurs. In Wales high water of spring tides may occur only in daylight in summer and nocturnal swimming may not be possible. The ebb tide swimming by C. volutator in Wales contrasts with the flood and ebb swimming of east coast amphipods and may reflect differences in their habitats. The former were collected close to the sea while the latter were 15 km up a narrow estuary and may represent a sub-population of amphipods with a disposition to swim early (on the flood tide) enabling them to colonise upstream habitats.

Trade-offs between competition and facilitation: a case study of vegetation management in the interior cedar–hemlock forests of southern British Columbia

2006 ◽  
Vol 36 (10) ◽  
pp. 2486-2496 ◽  
Author(s):  
Suzanne Simard ◽  
Alan Vyse
Keyword(s):  
British Columbia ◽  
Management Practices ◽  
Forest Policy ◽  
Structural Diversity ◽  
Vegetation Management ◽  
Facilitative Effect ◽  
Trade Offs ◽  
Substantial Risk ◽  
Population Sizes ◽  
Paper Birch

Vegetation-management practices are applied in temperate-zone forests on the assumption that changing the competitive environment between conifers and unwanted vegetation will improve conifer productivity. We review this assumption using research examining interactions between paper birch (Betula papyrifera Marsh.) and conifers in the highly productive Interior Cedar Hemlock zone of British Columbia. We have found that both competition and facilitation are important in young plantations, where paper birch competes for light, reducing growth of shade-intolerant conifers, but having a facilitative effect on shade-tolerant conifers. This facilitative effect may result from greater ectomycorrhizal diversity, population sizes of Armillaria ostoyae (Romagn.) Herink antagonistic bacteria, and associative nitrogen fixation in plantations where interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) is mixed with paper birch. Where paper birch is manually cut or girdled, conifers grow faster in diameter, but more die as a result of A. ostoyae root disease, and these responses increase with increasing weeding intensity. The weeding treatments do not affect plant community species richness but reduce paper birch dominants and increase understory structural diversity. British Columbia forest policy has been slow to respond to these findings, and we suggest that as a result, the forested landscape incurs substantial risk. We propose additional pathways for managing Interior Cedar Hemlock mixtures to ensure that the natural mix of forest types in the landscape is maintained.

scholarly journals Cereal rye to extend the grazing season

1995 ◽  
pp. 115-118
Author(s):  
David H. Sample' ◽  
Henry M. Bartholomew ◽  
R.Marc Sulc
Keyword(s):  
Crude Protein ◽  
Late Summer ◽  
Early Spring ◽  
Grazing Season ◽  
Cereal Rye ◽  
Late Autumn ◽  
Protein Levels ◽  
Winter Grazing ◽  
Autumn And Winter ◽  
Made In

Eleven cereal rye (&cafe cereale) cultivars, one triticale (Triticum secale) and one winter wheat (Triticum aestivum) cultivar were evaluated in 2 studies for their ability to extend the grazing season into the autumn and winter in southern Ohio. The cultivars, 5 in 1993 and 9 in 1994, were randomly assigned to replicated plots and planted in late summer. Plots were harvested in late autumn to determine dry matter (DM) yield and forage quality. Results from the two years indicate significant differences (P=O.O5) between cultivars for DM yield, crude protein(CP) and NDF levels. DM yields ranged from 1389 to 2470 kg/ha (1993) and 1018 to 2 124 kg/ha (1994). Crude protein levels ranged from 25.2 to 27.9% (1993) and 28.8 to 33.7% (1994). A second harvest of the 1994 plots was made in early spring 1995 for continued evaluation. Statistically significant differences again existed between the stockpiled cultivars. DM yields ranged from 1979 to 2980 kg/ha while crude protein levels ranged between 21.5 and 27.0% of DM. Results support the conclusion that selected cereal rye cultivars can produce excellent yields of high quality forage for late autumn and winter grazing in the Ohio climate. Keywords: cereal rye, extended grazing season, Secale cereale, triticale, wheat

scholarly journals Industrial bees: when agricultural intensification doesn’t impact local disease prevalence

2018 ◽  
Author(s):  
Lewis J. Bartlett ◽  
Carly Rozins ◽  
Berry J. Brosi ◽  
Keith S. Delaplane ◽  
Jacobus C. de Roode ◽  
...  
Keyword(s):  
Agricultural Intensification ◽  
Management Practices ◽  
Reproduction Number ◽  
Disease Prevalence ◽  
Policy Implications ◽  
List Type ◽  
Agricultural Systems ◽  
Population Sizes ◽  
Management Changes ◽  
Prevailing View

SummaryAlthough it is generally thought that the intensification of farming will result in higher disease prevalences there is little specific modelling testing this idea. We build multi-colony models to inform how ‘apicultural intensification’ is predicted to impact honeybee pathogen epidemiology at the apiary scale.Counter to the prevailing view, our models predict that intensification, captured though increased population sizes, changes in population network structure, and increased between-colony transmission, is likely to have little effect on disease prevalence within an apiary.The greatest impacts of intensification are found for diseases with relatively low R0 (basic reproduction number), however, such diseases cause little overall disease prevalence and therefore the impacts of intensification are minor. Furthermore, the smallest impacts of intensification are found for diseases with high R0 values, which we argue are typical of important honeybee diseases.Policy Implications: Our findings highlight a lack of support for the hypothesis that current and ongoing intensification leads to notably higher disease prevalences. More broadly, our work demonstrates the need for informative models of agricultural systems and management practices in order to understand the implications of management changes on diseases.

scholarly journals 'Grasslands Roa' tall fescue seed production: research and practice

1990 ◽  
pp. 77-80
Author(s):  
M.D. Hare ◽  
M.P. Rolston ◽  
W.J. Archie ◽  
J. Mckenzie
Keyword(s):  
Seed Production ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Late Winter ◽  
Winter Grazing ◽  
Production Research ◽  
Harvesting Techniques ◽  
Seed Crops ◽  
Seed Yields ◽  
Autumn And Winter

Seed yields of 'Grasslands Roa' tall fescue (Festuca arundinacea Schreb.) have ranged from 200 to 1450 kg/ha, with some hand harvested research plots producing 3600 kg/ha. Better management has increased seed yields, i.e., growing seed crops on deep, moistureretentive soils, lenient autumn and winter grazing, closing by late winter (mid July), applying 120 kg N/ha and careful harvesting techniques. Time of sowing, undersowing with barley crops, weed control and plant growth regulators are also discussed. Keywords tall fescue, seed production, Festuca arundinacea, 'Grasslands Roa'

scholarly journals Morphogenetic characteristics and management of Tanzania grass

2003 ◽  
Vol 38 (8) ◽  
pp. 991-997 ◽  
Author(s):  
Patricia Menezes Santos ◽  
Marco Antônio Alvares Balsalobre ◽  
Moacyr Corsi
Keyword(s):  
Accumulation Rate ◽  
Stem Elongation ◽  
Block Design ◽  
Stem Length ◽  
Panicum Maximum ◽  
Randomized Block Design ◽  
Tissue Turnover ◽  
Winter Grazing ◽  
Tiller Density ◽  
Autumn And Winter

The objective of this work was to evaluate the effect of grazing interval and period of evaluation over tissue turnover in Tanzania grass pastures (Panicum maximum cv. Tanzania) and to ascertain if herbage accumulation rate can be used as a criterion to establish a defoliation schedule for this grass in Southeast of Brazil. A randomized block design with a split-plot arrangement was used. The effect of three grazing intervals was evaluated within seven periods between October 1995 and September 1996. Responses monitored were leaf and stem elongation rates, leaf senescence rate, stem length, and tiller density. Net herbage accumulation rate was calculated using tissue turnover data. The grazing intervals for Tanzania grass should be around 38 days between October and April (spring and early autumn) and 28 days during the reproductive phase of the grass (April/May). Between May and September (late autumn and winter), grazing interval should be around 48 days. Herbage accumulation rate is not a good criterion to establish defoliation time for Tanzania grass. Studies on the effects of stem production in grazing efficiency, animal intake and forage quality are needed to improve Tanzania grass management.

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

An importance of soil humidification in forming of avifauna of arboreal plantation in the Biosphere reserve «Askania Nova» (un-reproductive period)

2016 ◽  
Vol 27 (3-4) ◽  
pp. 55-69
Author(s):  
M. A. Listopadsky
Keyword(s):  
Soil Moisture ◽  
Influence Factors ◽  
Data Communication ◽  
Biosphere Reserve ◽  
Reproductive Period ◽  
Defined Contribution ◽  
Separate Species ◽  
Steppe Birds ◽  
Reserve Forest ◽  
Autumn And Winter

With gradient analysis investigated the role of soil moisture in the formation of the modern population of birds in the reserve forest plantations. Soil moisture was divided into seven grades. For this purpose used grass cover and the coefficient of local moistening. His proposed PhD L. P. Travleev. This method allows knowing the degree of influence of soil moisture at the birds. We analyzed birds species composition, population, placement in space and power of influence factors (soil moisture). Investigations were carried out on the territory of the Biosphere Reserve «Askania Nova». We studied the birds which live in the reserve at the end of the summer, autumn and winter. This happened from 2006 to 2013 years. Specially was studied as permanently specific form of birds is found in a particular humidity. The degree of coupling was studied using the amount of information that transmits to the local bird humidification. For 68 species of birds are the options of the population density, coefficient koligatsii and data communication with the seven variants of soil moisture. For all kinds of set information «price» of each option dampening that contributes to the formation of a particular community of birds. Thus, the defined contribution to the formation of soil moisture forest bird communities. Species representation and density gradient within the test moisture is not in direct linear relationship from moisture and ranges from 11 (very coldly) to 50 species (moist soil). The density of the community varies from 0,5 birds / hectare (very dry) to 269 birds / hectare (fresh soil). The strongest link between the information and the formation of moisture gradient structure avifauna is typical in a fresh soil – bird on the edge, and wet – forest representatives. These types of humidification function is performed starting in the formation of two major blocks dendrophilous community. The steppe birds give way to forest representatives when the soil slightly moist. The main conclusion of our study includes the following: than wetter the soil the more species of birds lives in the forest; some graduation humidity are the most important for separate species of birds; it is very important for birds, there are places where one can drink water. Further invasive alien species can occur where the soil is moist. Forest with dry soil is already fully occupied by birds.

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