Grassland versus non-grassland bird abundance and diversity in managed grasslands: local, landscape and regional scale effects

2006 ◽  
Vol 16 (4) ◽  
pp. 871-881 ◽  
Author(s):  
Péter Batáry ◽  
András Báldi ◽  
Sarolta Erdős
Keyword(s):  
Scale Effects ◽  
Regional Scale ◽  
Bird Abundance ◽  
Grassland Bird ◽  
Abundance And Diversity

Impacts of road access on lake trout (Salvelinus namaycush) populations: regional scale effects of overexploitation and the introduction of smallmouth bass (Micropterus dolomieu)

2009 ◽  
Vol 66 (2) ◽  
pp. 212-223 ◽  
Author(s):  
Scott D. Kaufman ◽  
Ed Snucins ◽  
John M. Gunn ◽  
Wayne Selinger
Keyword(s):  
Lake Trout ◽  
Scale Effects ◽  
Regional Scale ◽  
Winter Season ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Excessive Pressure ◽  
Fishing Activity ◽  
Remote Lakes

In lake trout ( Salvelinus namaycush ) lakes of northeastern Ontario, Canada, aerial surveys of fishing activity on individual lakes (N = 589) and quantitative gillnet surveys (N = 65) were used to assess the effects of road access on angling effort and the presence of introduced smallmouth bass ( Micropterus dolomieu ). Angling effort, particularly during the open-water season, was highest and often exceeded estimated sustainable levels on lakes with good road access. Approximately 25% of the remote lakes also received excessive pressure during the winter season. Angler numerical responses to lake trout abundance were detected in remote lakes, but not in road-accessible lakes. Smallmouth bass were more prevalent in lakes with road access and human settlement (either cottages or lodges), supporting the theory that they were introduced into these lakes. Lake trout populations were depleted throughout much of the study range. Even without road access or smallmouth bass, lake trout abundance was still 47% lower than in unexploited reference lakes. When bass and (or) road access were present, lake trout abundance decreased by 77%. Remote lake trout populations in this area are clearly vulnerable to the negative impacts of improved access, a vector for both overexploitation and species introductions.

Patch-, Landscape-, and Regional-Scale Effects on Biota

2002 ◽  
pp. 58-83 ◽  
Author(s):  
Kathryn Freemark ◽  
Daniel Bert ◽  
Marc-André Villard
Keyword(s):  
Scale Effects ◽  
Regional Scale

The Effect of Grazing Regime on Grassland Bird Abundance in New York State

2017 ◽  
Vol 24 (sp8) ◽  
pp. 86-98 ◽  
Author(s):  
Lisa R. Cassidy ◽  
Gary Kleppel
Keyword(s):  
New York ◽  
New York State ◽  
Bird Abundance ◽  
Grassland Bird ◽  
York State

scholarly journals Bird diversity and abundance on two different shade coffee plantations in Guatemala

1998 ◽  
Vol 8 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Lorena Calvo ◽  
John Blake
Keyword(s):  
Vegetation Structure ◽  
Management Practices ◽  
Bird Diversity ◽  
Bird Abundance ◽  
Shade Coffee ◽  
Coffee Plantations ◽  
Bird Populations ◽  
Migrant Birds ◽  
Abundance And Diversity ◽  
Fertilizer Regimes

SummaryMany studies have examined differences in bird communities between shade and sun coffee plantations but less is known about how different management practices within shade coffee plantations affect bird populations. This study compares diversity and abundance of resident and migrant birds in two shade coffee plantations located in Palajunoj, Quetzaltenango, Guatemala, that differ in their farming practices (e.g. pruning schedules and fertilizer regimes) and, consequently, in vegetation structure. One plantation represents a traditional, polyculture shade system whereas the second represents a more modernized, monoculture shade system. Both plantations supported many resident and migrant birds. Bird abundance and diversity were significantly greater during both wet and dry seasons on the traditional farm, due largely to the vegetation structure resulting from the different management practices. All plantations typically classified as ‘shade coffee’ are not equivalent, much of their conservation value coming from the more diverse and structurally complex traditional polycultures rather than from the newer, monocultural systems. Coffee production techniques that affect the structural and floristic diversity of the vegetation (e.g. pruning, application of chemicals) have important consequences for birds.

scholarly journals Decadal declines in bird abundance and diversity in urban riparian zones

2017 ◽  
Vol 159 ◽  
pp. 48-61 ◽  
Author(s):  
Mélanie J. Banville ◽  
Heather L. Bateman ◽  
Stevan R. Earl ◽  
Paige S. Warren
Keyword(s):  
Riparian Zones ◽  
Bird Abundance ◽  
Abundance And Diversity

scholarly journals Modeling effects of crop production, energy development and conservation-grassland loss on avian habitat

2018 ◽  
Author(s):  
Jill A. Shaffer ◽  
Cali L. Roth ◽  
David M. Mushet
Keyword(s):  
North American ◽  
Energy Production ◽  
Crop Production ◽  
The United States ◽  
Prairie Pothole ◽  
Bird Abundance ◽  
Grassland Bird ◽  
The North ◽  
Essential Components ◽  
Bird Habitat

AbstractBirds are essential components of most ecosystems and provide many services valued by society. However, many populations have undergone striking declines as habitats have been lost or degraded by human activities. Terrestrial grasslands are vital habitat for birds in the North American Prairie Pothole Region (PPR), but grassland conversion and fragmentation from agriculture and energy-production activities have destroyed or degraded millions of hectares. Conservation grasslands can provide alternate habitat. In the United States, the Conservation Reserve Program (CRP) is the largest program maintaining conservation grasslands on agricultural lands, but conservation grasslands in the PPR have declined by over 1 million ha since the program’s zenith in 2007. We used an ecosystem-services model (InVEST) parameterized for the PPR to quantify grassland-bird habitat remaining in 2014 and to assess degradation status of this remaining habitat as influenced by crop and energy (i.e., oil, natural gas, and wind) production. We compared our resultant habitat-quality ratings to grassland-bird abundance data from the North American Breeding Bird Survey to confirm that ratings were related to grassland-bird abundance. Of the grassland-bird habitat remaining in 2014, about 18% was degraded by nearby crop production, whereas energy production degraded an additional 16%. We further quantified changes in availability of grassland-bird habitat under various land-cover scenarios representing incremental losses (10%, 25%, 50%, 75%, and 100%) of CRP grasslands from 2014 levels. Our model identified 1 million ha (9%) of remaining grassland-bird habitat in the PPR that would be lost or degraded if all CRP conservation grasslands were returned to crop production. In addition to direct losses, an economic climate favoring energy and commodity production over conservation has resulted in substantial degradation of remaining grassland-bird habitat across the PPR. Other grassland regions of the world face similar challenges in maintaining avian habitat.

Sub-grid scale representation of halogen chemistry in volcanic plumes based on 1D MOCAGE model simulations

2021 ◽  
Author(s):  
Virginie Marécal ◽  
Ronan Voisin-Pessis ◽  
Tjarda Roberts ◽  
Paul Hamer ◽  
Alessandro Aiuppa ◽  
...  
Keyword(s):  
Transport Model ◽  
Scale Effects ◽  
Regional Scale ◽  
Global Scale ◽  
Horizontal Resolution ◽  
Mt Etna ◽  
Modelling Studies ◽  
1D Model ◽  
High Concentrations ◽  
The Impact

<p>Halogen halides emitted by volcanoes are known to rapidly convert within plumes into BrO while depleting ozone, as clearly shown by observations and models over the past 2 decades (e.g. review by Gutmann et al., 2018). So far, most of the modelling studies have focused on the plume processes occurring in the first few hours after the emission. The only study at the regional scale is that of Jourdain et al. (2016). They assessed the impact of volcanic halogens for a period of strong degassing of the Ambrym volcano, showing in particular its effect on the atmospheric oxidizing capacity and methane lifetime.</p><p>A step further would be to quantify the impact of volcanic halogens at the global scale using global chemistry models. This type of model uses a horizontal resolution (greater than 50 km) that is much coarser than the plume size. This raises the issue of, whether at this resolution, it is possible to represent the chemistry occurring under high concentrations within the plume. To assess this, a sub-grid scale parameterization is proposed. It has been tested in the 1D version of MOCAGE global and regional chemistry transport model for a short eruption of Mt Etna on the 10<sup>th</sup> of May 2008. The results show that while using the subgrid-scale plume parameterization or not does change the timing of when the maximum BrO occurs but does not affect the predicted maximum concentration. The same finding is made when using a range of different settings in the parameterization regarding dilution of the plume with its environment. The 1D model results show a sensitivity of BrO formation to parameters other than the sub-grid scale effects: composition of the plume at the vent, injection height of the emissions, and time of the day when the eruption takes place.</p>

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