The dynamics of hazel grouse (Bonasa bonasia L.) occurrence in habitat fragments

2000 ◽  
Vol 78 (3) ◽  
pp. 352-358 ◽  
Author(s):  
Johan Åberg ◽  
Jon E Swenson ◽  
Henrik Andrén
Keyword(s):  
Critical Level ◽  
Fragment Size ◽  
Coniferous Forest ◽  
Suitable Habitat ◽  
Hazel Grouse ◽  
Bonasa Bonasia ◽  
Intensively Managed

The aim of this study was to evaluate the effects of habitat fragment size and isolation on the dynamics of hazel grouse (Bonasa bonasia L.) occurrence. Habitat fragments surrounded by nonhabitat coniferous forest, in an intensively managed forested landscape, were censused during seven seasons. None of the 33 habitat fragments were occupied in all seven seasons and 7 were never occupied. Turnover occurred in 79% of the habitat fragments. The most common occupation of a habitat fragment was by only one hazel grouse male (84%). Thus, the dynamics of hazel grouse occurrence in the habitat fragments was basically monitored on the scale of individuals. Large and less isolated habitat fragments with a high amount of cover were occupied significantly more often than small, isolated fragments. The effect of size appeared most clearly when analyzing the total number of hazel grouse occupying a habitat fragment. The appearance of hazel grouse in the habitat fragments was best explained by the amount of cover, distance to the nearest suitable habitat, and size of the habitat fragment. The effects of interfragment distance on the occurrence and appearance of hazel grouse implies that the habitat has become functionally disconnected for hazel grouse and suggests that the amount of suitable hazel grouse habitat left in this landscape has fallen below a critical level.

Habitat separation by sympatric forest grouse in Fennoscandia in relation to boreal forest succession

1993 ◽  
Vol 71 (7) ◽  
pp. 1303-1310 ◽  
Author(s):  
Jon E. Swenson ◽  
Per Angelstam
Keyword(s):  
Forest Succession ◽  
Deciduous Trees ◽  
Black Grouse ◽  
Forest Stands ◽  
Old Growth ◽  
Successional Stage ◽  
Hazel Grouse ◽  
Bonasa Bonasia ◽  
Successional Stages ◽  
Intensively Managed

Sympatric forest grouse in intensively managed conifer-dominated forests of the southern boreal zone in Sweden occupied different forest successional stages. Black grouse (Tetrao tetrix) selected forest stands 0 – 20 years old, hazel grouse (Bonasa bonasia) selected those 20 – 50 years old, and capercaillie (Tetrao urogallus) selected those ≥90 years old. Moreover, hazel grouse also selected stands with 1 – 10% deciduous trees, whereas capercaillie selected stands with no deciduous trees. The relative numbers of each grouse species were similar in two areas of intensively managed industrial forest, but differed in an area where forestry was less intensive and where forests had old-growth characteristics, i.e., they were old and multi-layered. Black grouse dominated in the intensively managed areas, whereas hazel grouse dominated in the less intensively managed area. We suggest that under natural conditions, black grouse inhabited the early-successional stages of forest following burns, hazel grouse inhabited the next, denser, successional stage and also old-growth spruce-dominated forests in fire refugia, and capercaillie inhabited stands of open, old, pine-dominated forest maintained by forest fire. The black grouse appears to be preadapted to the modern system of clearcut forest management. However, this system is clearly detrimental to the hazel grouse and capercaillie. To maintain all three species in a managed landscape, forest managers must strive to mimic more closely the natural variation in types and sizes of forest stands.

Spatiotemporal variability in sources of suspended sediments from a Scottish river using compound-specific isotope analysis (CSIA): a nested catchment approach

2020 ◽  
Author(s):  
Pranav Hirave ◽  
Miriam Glendell ◽  
Axel Birkholz ◽  
Christine Alewell
Keyword(s):  
Land Use ◽  
Arable Land ◽  
Isotope Analysis ◽  
Coniferous Forest ◽  
Suspended Sediments ◽  
Mixing Model ◽  
Spatiotemporal Variability ◽  
Fingerprinting Technique ◽  
Compound Specific Isotope Analysis ◽  
Intensively Managed

<p>The River Dee is one of the major river systems in Scotland, renowned for its economically important Atlantic salmon (<em>Salmo salar</em>) population. The Tarland Burn (70 km<sup>2</sup>), an intensively managed catchment, is a significant source of nutrients and suspended sediments (SS) to the River Dee, causing degradation of its water quality. To trace the SS sources in the Tarland Burn catchment, we used compound-specific isotope analysis (CSIA) fingerprinting technique. The CSIA fingerprinting technique applied in this study involved (i) carbon isotope ratio (δ<sup>13</sup>C) measurements of plant derived long-chain fatty acids (LCFAs) extracted from source soils and from river SS as a mixture signal as input tracer values, and (ii) computation of source proportions in the mixture using an end member mixing model ‘MixSIAR’ which is based on the Bayesian approach.</p><p>Source soils were sampled from the land-use types observed in a headwater catchment (10 km<sup>2</sup>) i.e. arable, temporary grassland under arable rotation, permanent grassland, coniferous forest, heather moorland and riparian zone. SS samples were collected from the headwaters, second order streams, and also from the outlet of the Tarland Burn catchment, representing a nested sampling approach. A comparison of the two common suspended sediment collection techniques to understand the role of sampling technique and associated particle sizes resulted in no substantial difference in the tracer values. SS were sampled once every two months over a period of 14 months between May 2017 and June 2018. δ<sup>13</sup>C values of LCFAs (even homologues between C<sub>22:0</sub> - C<sub>30:0</sub>) of the SS (mixture) were within the range of source soils corresponding tracer values, confirming their conservative behaviour during transport.</p><p>Quantification of source proportions using mixing model suggested that headwater streams SS originated predominantly from permanent grasslands. They are largely located on steep topography, leading to higher hydrological connectivity and possible increased pressure from livestock. Although plantation forestry and heather moorland are prominent land-uses in the catchment, their contribution as SS sources is marginal. More intensive arable land use in the lowland areas of Tarland catchment was reflected by their high contribution to SS at the downstream locations. More intensive rainfall events during winter likely led to higher sediment fluxes from the normally less connected permanent grasslands at the catchment outlets during high flow.</p><p>Our attempt of gathering source soil information from a headwater region of a catchment and upscaling this information to model the source proportions in downstream mixtures integrating the whole catchment was successful, however uncertainties increased for the downstream results</p>

scholarly journals Identifying habitat suitability for hazel grouse Bonasa bonasia at the landscape scale

2006 ◽  
Vol 12 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Lukas Mathys ◽  
Niklaus E. Zimmermann ◽  
Niklaus Zbinden ◽  
Werner Suter
Keyword(s):  
Habitat Suitability ◽  
Landscape Scale ◽  
Hazel Grouse ◽  
Bonasa Bonasia

scholarly journals Thirteen years on the hunt for Buxbaumia viridis in the Czech Republic: still on the tip of the iceberg?

2014 ◽  
Vol 83 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Eva Holá ◽  
Jan Vrba ◽  
Renata Linhartová ◽  
Eva Novozámská ◽  
Magda Zmrhalová ◽  
...  
Keyword(s):  
Czech Republic ◽  
Coniferous Forest ◽  
Western Carpathians ◽  
Distribution Model ◽  
Suitable Habitat ◽  
Natural Forests ◽  
Habitat Directive ◽  
The Czech Republic ◽  
Area Of Occupancy ◽  
Historical Sites

Rare epixylic moss <em>Buxbaumia viridis</em>, which is one of the “Annex II” species of the European “Habitat directive”, has been recorded at 124 localities in the Czech Republic in course of the last 13 years. Most of them were discovered in the last five years following a dedicated search at both historical sites of occurrence and new localities with putatively suitable habitat conditions. The recent and historical area of occupancy and extent of occurrence are not obviously different, although most of the recent localities are concentrated in the Western Carpathians and the Hrubý Jeseník Mts. Surprisingly, only 38% of the localities are located in natural forest habitats, of which herb-rich and acidophilous beech forests were among the most commonly inhabited ones. The rest of occurrences were recorded in non-natural forests (habitats strongly influenced or created by man), particularly the coniferous forest plantations. Sufficient amount of decaying wood of the advanced decay stages, as well as sufficient and constant humidity are crucial prerequisites for the occurrence of <em>B. viridis</em> in both types of forests. True epixylic moss <em>Herzogiella seligeri</em> and the liverwort <em>Chiloscyphus profundus</em> were recorded as the most common associated species, while the rest of commonly co-occurring species were facultatively epixylic, ground or ubiquitous bryophytes; other specialized and rare epixylic mosses or liverworts were only rarely recorded. We also designed a potential distribution model for <em>B. viridis</em> based on the distribution of habitats most commonly occupied by the studied moss. Despite the simplicity of the model, its close match with the recent distribution in the Western Carpathians, the Hrubý Jeseník Mts. and Šumava Mts. supports its relevance for the real distribution of <em>B. viridis</em>.

Modelling habitat selection of the cryptic Hazel Grouse Bonasa bonasia in a montane forest

2009 ◽  
Vol 150 (4) ◽  
pp. 717-732 ◽  
Author(s):  
Daniel Müller ◽  
Boris Schröder ◽  
Jörg Müller
Keyword(s):  
Habitat Selection ◽  
Montane Forest ◽  
Hazel Grouse ◽  
Bonasa Bonasia ◽  
Selection Of

scholarly journals Plantations and biodiversity: A comment on the debate in New Brunswick

2005 ◽  
Vol 81 (2) ◽  
pp. 265-269 ◽  
Author(s):  
Matthew G Betts ◽  
Antony W Diamond ◽  
Graham J Forbes ◽  
Kate Frego ◽  
Judy A Loo ◽  
...  
Keyword(s):  
New Brunswick ◽  
Tree Species ◽  
Native Species ◽  
Woody Debris ◽  
Scientific Information ◽  
Landscape Scale ◽  
Suitable Habitat ◽  
Negative Consequences ◽  
Intensively Managed ◽  
The Impact

The importance of biodiversity has become widely recognized but the best methods for conserving forest biodiversity are still being debated. Central to this debate is the influence of plantations and managed stands on local and landscape-scale biodiversity. A recent paper by Erdle and Pollard in The Forestry Chronicle (2002), which concluded that few plantations are strict monocultures in terms of the total number of tree species, could be interpreted as making the case that plantations have relatively minor consequences for biodiversity. We argue that: (1) it is not only the number of species, but also the identities and relative abundances of species that are of ecological importance, and (2) defining biodiversity in terms of tree species alone is of limited applicability. Existing research in New Brunswick on the impact of plantations on biodiversity at the stand scale reveals potentially significant biodiversity losses, at least in certain taxa. The proposal that incorporating more structural elements (e.g., snags, coarse woody debris, vertical structure) and retaining greater tree species diversity to ameliorate negative consequences of plantations remains a hypothesis to be tested in this region. Scientific information gathered in the following areas will allow better decision making: (1) to what degree are older plantations used by native species? (2) are productivity and survivorship of vertebrates in intensively managed stands similar to those in unmanaged forest? (3) are intensively managed stands suitable habitat for non-vertebrates? (4) are there thresholds in the response of some species to landscape-scale habitat loss caused by intensive forest management? Key words: plantations, biodiversity, species composition, landscape scale, stand structures

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