Search results for "Richness"

Gestion territoriale des adventices : effets des propriétés du paysage sur les communautés adventices et sur leur régulation par les carabidae

2015

Landscape-scale management is known to affect pest and biodiversity levels in agroecosystems. Here, we focus on the lanscape drivers of arable weeds, first by reviewing evidence of direct landscape effects on weed species richness and abundance and then by analyzing current knowledge on landscape effects on carabids, which are well-known weed seed predators that contribute to the biological regulation of weeds. Our analysis shows that (i) heterogeneous landscapes usually harbor higher species richness and more diversified communities than simple ones, (ii) total weed and carabid abundances appear seldomly affected by the landscape context of arable fields and (iii) weed seed predation in fi…

Distribution of the weed flora in a small agricultural landscape

2023

Harnessing the biodiversity value of Central and Eastern European farmland

2015

A large proportion of European biodiversity today depends on habitat provided by low‐intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species‐rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively ti…

Extrapolation of the Species Accumulation Curve for Incomplete Species Samplings: A New Nonparametric Approach to Estimate the Degree of Sample Compl…

2015

9 pages; International audience; Incomplete species samplings are deemed to remain the common practice in those groups of animals, such as small or micro- invertebrates, with numerous species that often are more or less difficult to detect in the field. Thus, extrapolating the Species Accumulation Curve as far as possible beyond the actual sample size may thus serve as a useful (although imperfect) surrogate to the desired, but practically inaccessible, complete samplings. In this context, several kinds of theoretical or empirical models for the Species Accumulation Curve and also a lot of estimators of the asymptotic limit of the Curve (i.e. total species richness) have been proposed. The …

Long-term changes in breeding bird community of a Primeval Temperate Forest: 45 years of Censuses in the Białowieża National Park (Poland)

2022

W pracy omówiono długoterminowe trendy zmian liczebności 30 leśnych, pospolitych ptaków lęgowych na 7 stałych powierzchniach próbnych w Białowieskim Parku Narodowym w latach 1975– 2019 (wschodnia Polska, dalej BPN, Fig. 1). Przeanalizowano zmiany w składzie ugrupowań ptaków lęgowych w trzech najważniejszych typach drzewostanów pierwotnych w BPN: łęgach (Fig. 2), grądach (Fig. 3) i borach (Fig. 4). Cenzusy kontynuowane w latach 2015–2019 z wykorzystaniem kombinowanej metody kartograficznej na siedmiu stałych powierzchniach próbnych w BPN, monitorowanych od 1975 r., w tym dwóch na skraju lasu i pięciu w jego wnętrzu wykazały gniazdowanie 69 gatunków ptaków. Najwięcej gatunków gniazdowało w łę…

Effects of undergrowth removal and edge proximity on ground beetles and vascular plants in urban boreal forests

2019

Urban forests are regularly managed for human safety and esthetic reasons, but they are crucial habitat for many species. Removals of undergrowth occur commonly in these forests, yet the ecological consequences of these operations are poorly understood. We sampled ground beetles (Coleoptera, Carabidae) and vascular plants along 20-m edge gradients in Finnish urban forests, in five stands treated 0.5–2.5 years earlier with undergrowth removal and in five untreated stands. We hypothesized that undergrowth removal and edge proximity would benefit opportunistic and open-habitat species, whereas shady-habitat species would be affected negatively. (1) Regarding carabids, diversity and evenness in…

The community of Cystoseira brachycarpa J. Agardh emend. Giaccone (Fucales, Phaeophyceae) in a shallow hydrothermal vent area of the Aeolian Islands …

2014

A Cystoseira brachycarpa community from a vent area off Panarea Island (Italy) was investigated in two sites at different pH values. At low pH, species richness and coverage were low and the community displayed a reduced reproductive capacity. Conversely, at normal pH, dense canopies of fertile C. brachycarpa were found.

Helminth Communities in Audouin's Gulls, Larus audouinii from Chafarinas Islands (Western Mediterranean)

1999

A survey of intestinal helminth communities of Audouin's s gulls Larus audouinii, from their breeding colonies in Chafarinas Islands, western Mediterranean, Spain was conducted to determine the abundance and species diversity of intestinal parasites of these birds. The sample of 58 gulls harbored intestinal helminth infracommunities composed of species that are gull generalists, including the digeneans Cardiocephalus longicollis, Knipowitschiatrema nicolai, Condylocotyla pilodora, and Aporchis massiliensis, and the cestode Tetrabothrius cylindraceus. Two nematodes are waterfowl generalists (Cosmocephalus obvelatus and Paracuaria adunca), whereas the digenean Acanthotrema armata is an Audoui…

On Harvestmen from the Soutpansberg, South Africa, with Description of a New Species ofMonomontia(Arachnida: Opiliones)

2008

The harvestman fauna of the Western Soutpansberg was investigated during two collecting trips. Comments are made on the variability, ecology and remarkable morphological features of the collected material. Characters are displayed and differences to type series are highlighted. Monomontia neglecta sp. n. is described from material housed at the Natal Museum. Metabiantes leighi Pocock, 1902 is recorded for the first time for the Soutpansberg area. A species list is provided, listing all known records and the state of endemism. The relative species richness of the eastern Soutpansberg is discussed in comparison with the western area.

Analysis of the epiphytic bryophyte diversity of Sicily

2009

Sicilian epiphytic bryophyte diversity, based on literature and unpublished data, is assessed both quantitatively and qualitatively. The total number of taxa found on trees or shrubs is 133 (116 mosses and 17 liverworts). Among them, 38 are customary epiphytic, 21 cortico-saxicolous, 13 are indifferent and 61 occasionally epiphytic taxa. The most represented families are Orthotrichaceae (19.1%), which consists above all of several typically corticicolous species, Pottiaceae (19.1%) and Brachytheciaceae (12.6%) which both include many taxa that mainly colonize rock or ground substrates. From the chorological point of view, temperate taxa (33.8%) prevail, followed by oceanic-Mediterranean tax…