The effects of silvicultural disturbances on cryptogam diversity in the boreal-mixedwood forest

2002 ◽  
Vol 32 (1) ◽  
pp. 38-51 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell
Keyword(s):  
Species Richness ◽  
Species Abundance ◽  
Diversity Indices ◽  
Forest Harvesting ◽  
Aerial Application ◽  
Forest Diversity ◽  
Four Blocks ◽  
Abundance And Diversity ◽  
Species Richness And Abundance ◽  
And Function

In northern forests, cryptogams (spore producing plants) occupy a key position in forest ecosystem diversity and function. Forest harvesting and silvicultural practices have the potential to reduce cryptogam diversity. This project uses four blocks that were mechanically site prepared, planted with a single conifer species, and subsequently subjected to five conifer release treatments: (1) motor-manual cleaning, (2) mechanical brush cutting, (3) aerial application of triclopyr, (4) aerial application of glyphosate, and (5) control (untreated clearcut). Five 10 × 10 m subplots were installed in each of the five treatment plots and the uncut forest on the four blocks. Botanical surveys were conducted before and 1–5 years after treatments. Species richness and abundance, Shannon's and Heip's indices, and rank abundance diagrams clearly show that richness and abundance were affected by silvicultural treatments. Vegetation management treatments resulted in significant reductions in cryptogam diversity, to the point that only a few colonists and drought-tolerant species remained. Cryptogam diversity was ranked in the following order: forest > clearcut > mechanical clearing > herbicide treatment. Herbicide treatments had the greatest initial effect on species richness, species abundance, and diversity indices. Cryptogam diversity showed signs of recovery 5 years after treatments. Missed strips (untreated areas) within a clearcut provided a refuge for remnant communities of forest cryptogams that could play a key role in the rehabilitation forest diversity.

Effect of indaziflam on native species in natural areas and rangeland

2019 ◽  
Vol 12 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Shannon L. Clark ◽  
Derek J. Sebastian ◽  
Scott J. Nissen ◽  
James R. Sebastian
Keyword(s):  
Species Richness ◽  
Weed Management ◽  
Native Species ◽  
Species Abundance ◽  
Unintended Consequences ◽  
Ecological Impacts ◽  
Limited Information ◽  
Perennial Species ◽  
Temporary Reduction ◽  
Species Richness And Abundance

AbstractMinimizing the negative ecological impacts of exotic plant invasions is one goal of land management. Using selective herbicides is one strategy to achieve this goal; however, the unintended consequences of this strategy are not always fully understood. The recently introduced herbicide indaziflam has a mode of action not previously used in non-crop weed management. Thus, there is limited information about the impacts of this active ingredient when applied alone or in combination with other non-crop herbicides. The objective of this research was to evaluate native species tolerance to indaziflam and imazapic applied alone and with other broadleaf herbicides. Replicated field plots were established at two locations in Colorado with a diverse mix of native forbs and grasses. Species richness and abundance were compared between the nontreated control plots and plots where indaziflam and imazapic were applied alone and in combination with picloram and aminocyclopyrachlor. Species richness and abundance did not decrease when indaziflam or imazapic were applied alone; however, species abundance was reduced by treatments containing picloram and aminocyclopyrachlor. Species richness was only impacted at one site 1 yr after treatment (YAT) by these broadleaf herbicides. Decreases in abundance were mainly due to reductions in forbs that resulted in a corresponding increase in grass cover. Our data suggest that indaziflam will control downy brome (Bromus tectorumL.) for multiple years without reduction in perennial species richness or abundance. IfB. tectorumis present with perennial broadleaf weeds requiring the addition of herbicides like picloram or aminocyclopyrachlor, forb abundance could be reduced, and in some cases there could be a temporary reduction in perennial species richness.

Ecology of Dolichopodidae (Diptera) in a wetland habitat and their potential role as bioindicators

2011 ◽  
Vol 6 (1) ◽  
pp. 118-129 ◽  
Author(s):  
Ivan Gelbič ◽  
Jiří Olejníček
Keyword(s):  
Species Richness ◽  
Potential Role ◽  
Species Abundance ◽  
Abundant Species ◽  
Seasonal Activity ◽  
Wet Meadow ◽  
Emergence Traps ◽  
Abundance And Diversity ◽  
Pan Traps ◽  
Malaise Traps

AbstractEcological investigations of long-legged flies (Dolichopodidae) were carried out in wet meadow wetlands near České Budějovice, Czech Republic. Sampling was performed during the adult flies’ seasonal activity (March–October) in 2002, 2003 and 2004 using yellow pan traps, Malaise traps, emergence traps, and by sweeping. Altogether 5,697 specimens of 78 species of Dolichopodidae were collected, identified and analysed. The study examined community structure, species abundance, and diversity (Shannon-Weaver’s index - H’; Sheldon’s equitability index - E). Chrysotus cilipes, C. gramineus and Dolichopus ungulatus were the most abundant species in all three years. Species richness and diversity seem strongly affected by soil moisture.

scholarly journals Avian Species Abundance and Richness in a  Variably Urbanised Landscape in Wellington City,  New Zealand

2021 ◽  
Author(s):  
◽  
Jennifer Glynn Vinton
Keyword(s):  
Species Richness ◽  
Patch Size ◽  
Species Abundance ◽  
Bird Species ◽  
Habitat Patch ◽  
Avian Community ◽  
Patch Structure ◽  
Avian Biodiversity ◽  
Species Richness And Abundance ◽  
Species Ecology

<p>Avian community composition fluctuates across the landscape at different scales of space and time. These fluctuations may be modified at the broader scale of landscape and at the local scale of habitat patch. A species' ecology also influences its occurrence and abundance in the landscape. This thesis investigates the spatial and temporal distribution of the avian community in Wellington. Wellington is an interesting case study because it has a diverse range of landscapes influenced by the proximity of hills to the coast (see Appendix 3). I assess the effect of landscape classification on the richness and abundance of birds and the role of fine patch structure in shaping this distribution. My study was located within a 5-km radius of Wellington City's central business district (41 degrees 16' S, 174 degrees 46' E). I used six strip-transects divided into 400m length segments that traversed through high to lower density residential suburbs and green space inter-digitated with built habitat, and established five-minute count (FMBC) points at each segment interval along these routes for a total of 49 points. I used ArcGIS to analyse the habitat patch types in the 100-m areas surrounding the FMBC. I recorded avian species type and abundance along the strips and at the FMBC during the morning and evening. A total of 35 bird species and 10966 individuals were recorded along the strip-transects and 34 bird species and 5960 individuals at the FMBCs. House sparrow, then starling and blackbacked gull, rock pigeon, blackbird and silvereye were the most common and widely spread species. Results indicated that landscape type modified avian biodiversity with the highest number of species (S) recorded in green landscapes (n = 10, S = 15.9) and the lowest in wharf littoral (n = 2, S = 7.5) and low-density commercial sites (n = 3, S = 6.67). The diversity of the landscape within an area did not influence avian biodiversity. I found that total species abundance did not change across the landscape but that the species' ecology did influence where it occurred and its abundance in the landscape. Dietary diversity particularly influenced a species' abundance. Both season and time of day altered species richness and abundance, with lower values of richness recorded in autumn (morning period = 13.5, evening period = 10.7). I found that avian communities in the Wellington urban area were dominated by six common species but that many more species were present in much lower numbers at fewer sites. Results showed an inverse relationship between species richness and abundance - while the greater biomass (abundance) of birds concentrated at FMBC within the built commercial centre and surrounding higher density housing areas, richness increased with distance from the built centre to residential and green sites. I found no relationship between species richness and the total number of individuals present at any point, and the total biomass and abundance of birds was also independent of patch size. Neither habitat patch diversity nor average patch size influenced species diversity across the community of birds, but the effect of average patch size was less at patches between 300 and 1500 metres. The abundance of some individuals in their favoured patch type did vary in response to patch structure with the strongest relationships seen for blackbird and house sparrow. These results suggest that birds are responding to cues at the larger scale of landscape first rather than to fine patch structure within the urban setting, and therefore that landscape is a more important influence in driving bird biodiversity.</p>

scholarly journals STRUKTUR KOMUNITAS IKAN TARGET DI TERUMBU KARANG PULAU HOGOW DAN PUTUS-PUTUS SULAWESI UTARA

2011 ◽  
Vol 7 (2) ◽  
pp. 60 ◽  
Author(s):  
Unstain NWJ Rembet ◽  
Mennofatria Boer ◽  
Dietriech G Bengen ◽  
Achmad Fahrudin
Keyword(s):  
Multivariate Analysis ◽  
Species Richness ◽  
Coral Reef ◽  
Species Diversity ◽  
Species Abundance ◽  
Controlling Factors ◽  
Ecological Groups ◽  
Species Evenness ◽  
Target Fish ◽  
Abundance And Diversity

ABSTRACTCommunity structure of target fishes was analyzed to understand their response to different conditions of coral reefs in several places of Hugow and Putus-Putus islands. This study focused on species abundance and diversity including Shannon-Wiener’s species diversity (H’), species richness (SR), species evenness (J’) and dominance (d) indices, respectively. A multivariate analysis was used for the classification or correspondence factorial analyses. The result recorded 4,501 individuals belonging to 52 species of target fishes. Both cluster and correspondence analyses clearly recognized 3 groups of target fish with 2 major controlling factors for the development of these 3 ecological groups, i.e. coral reef conditions and geographic position to the hydrodynamic condition.ABSTRAKStruktur komunitas ikan target dianalisis untuk melihat respon ikan target terhadap perbedaan kondisi terumbu karang di beberapa lokasi Pulau Hogow dan Putus-Putus. Penelitian ini dilakukan pada bulan Oktober 2010 dengan pengambilan data di 6 stasiun. Dalam penelitian ini telah dikaji variabel komunitas seperti kelimpahan dan keanekaragaman spesies termasuk indeks keanekaragaman spesies Shannon-Wiener (H’), indeks kekayaan spesies (SR), indeks kemerataan spesies (J’) dan indeks dominasi (d). Untuk melihat assemblage ikan target dilakukan analisis multivariat baik analisis klasifikasi maupun analisis faktorial koresponden. Dalam penelitian ini diperoleh 4501 indidu yang termasuk dalam 52 spesies ikan target. Analisis multivariat baik analisis cluster maupun analisis koresponden telah memisahkan dengan jelas 3 grup ikan target, dimana terdapat dua faktor utama pengendali pembentukan 3 grup ekologis ini yakni faktor kondisi terumbu karang dan faktor posisi lokasi terhadap kondisi hidrodinamika perairan.

scholarly journals Structure of 0+ juvenile fish assemblages in the modified upper stretch of the River Elbe, Czech Republic 

2014 ◽  
Vol 59 (No. 1) ◽  
pp. 35-44 ◽  
Author(s):  
Z. Valová ◽  
M. Janáč ◽  
J. Švanyga ◽  
P. Jurajda
Keyword(s):  
Species Richness ◽  
Fish Assemblage ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
Species Abundance ◽  
Shannon Index ◽  
Catch Per Unit Effort ◽  
River Elbe ◽  
Nursery Habitats ◽  
Species Richness And Abundance

In August 2007, the 0+ juvenile fish assemblage of the upper River Elbe was surveyed using electrofishing. Thirty-six localities were sampled along a 177 km long section between the towns of Verdek and Brand&yacute;s nad Labem (river km (RKM) 136&ndash;313). Four localities with natural riverbeds, 14 channelized stretches, nine beaches, and nine backwaters were sampled. Altogether, 4521 0+ juvenile fishes were caught, belonging to 26 species. A decrease in species richness and abundance was evident near Hradec Kr&aacute;lov&eacute;, while decreased species abundance was noted along the navigated stretch below Přelouč. The highest catch-per-unit-effort (CPUE), species richness, and Shannon index values were observed at beach habitats, the lowest in channelized habitats, and intermediate values in backwaters. Generally, rare beach habitats had significantly more rheophilic species than other habitats, while backwaters had significantly more eurytopic species and higher CPUE for limnophilic species. Backwaters and channel habitats, however, did not differ in any other 0+&nbsp;fish assemblage parameter studied. The study demonstrated the importance of beaches for fish assemblages along navigable channels. Surprisingly, however, backwaters were not confirmed as important nursery habitats.

scholarly journals Relationships between Plant Diversity and Grasshopper Diversity and Abundance in the Little Missouri National Grassland

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
David H. Branson
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Diversity ◽  
Plant Species Richness ◽  
Coarse Grained ◽  
Grasshopper Species ◽  
Species Richness And Diversity ◽  
Western North Dakota ◽  
Abundance And Diversity ◽  
Species Richness And Abundance

A continuing challenge in orthopteran ecology is to understand what determines grasshopper species diversity at a given site. In this study, the objective was to determine if variation in grasshopper abundance and diversity between 23 sites in western North Dakota (USA) could be explained by variation in plant species richness and diversity. In this system with relatively low plant diversity, grasshopper species richness and abundance were not significantly associated with plant species richness in either year. Although a number of significant associations between plant diversity and grasshopper diversity were found through regression analyses, results differed greatly between years indicating that plant species richness and diversity did not lead to strong effects on grasshopper diversity metrics. Plant species richness appears to be too coarse grained to lead to accurate predictions of grasshopper species richness in this system dominated by generalist grasshopper species.

scholarly journals ASSESSMENT OF PLANT DIVERSITY INDICES OF GOMATI RIPARIAN CORRIDORS IN DISTRICT JAUNPUR, INDIA

2014 ◽  
Vol 20 ◽  
pp. 71-76
Author(s):  
Mayank Singh ◽  
M. P. Singh
Keyword(s):  
Species Richness ◽  
Plant Community ◽  
Diversity Indices ◽  
Riparian Ecosystems ◽  
Ecological Studies ◽  
Riparian Corridors ◽  
Central Elements ◽  
Different Seasons ◽  
Density Values ◽  
And Function

Riparian ecosystems, the central elements in many landscapes, are described as an ecotone stretchedout across the landscape because of their shape diversity and function as filters and corridors still theyare most disturbed and threatened by humans. The present work deals with seasonal dynamics inplant diversity indices at two distinct sites (I and II) at ecotonal belts of River Gomati, Jaunpur (U.P.).The diversity indices of plant community have been computed on the basis of density values recordedfrom April, 2012 to March, 2013. Site I showed more species richness and evenness as compared tosite II. Shannon and Weaver, Evenness, Marglef’s, McIntosh and Menhinic diversity indices valueswere higher at site I compared to site II. In contrast, the concentration dominance showed highervalue at site II, whereas Simpson values of diversity have fluctuated in different seasons at both thesites (I and II). It finally deals to formulate strategies and methods for the management of plantdiversity and other natural resources based on various ecological studies, and logical grounds.DOI: http://dx.doi.org/10.3126/eco.v20i0.11444ECOPRINTAn International Journal of EcologyVol. 20, 2013Page: 71-76

Diversity

2009 ◽  
Author(s):  
John S. Gray ◽  
Michael Elliott
Keyword(s):  
Species Richness ◽  
Diversity Indices ◽  
Abundance Ratio ◽  
Number Of Species ◽  
True Diversity ◽  
Species Richness And Abundance ◽  
Evenness Indices ◽  
Number Of Individuals

In the previous chapter we covered ways of describing samples of benthos, but specifically did not include diversity. We can talk of primary community variables, such as abundance (A), species richness (S) and biomass (B), and derived variables from these such as true diversity indices, evenness indices, and ratios indicating the relationship between species richness and abundance (A/S, the abundance ratio or the average abundance per species) and between biomass and abundance (B/A, the biomass ratio or the mean biomass per individual). Diversity is not just simply about the number of species found in a sample or area, but also uses data on the abundances of individuals among the species and the way those abundances are distributed among the species within the assemblage. There are many ways of describing diversity. Here we give a summary of the most important ones and reference sources of recent literature on the subject (see also the data analysis summary in Chapter 11). In the following section we consider simple indices (univariate) as measures of diversity; multivariate methods of analysing patterns will be covered in Chapter 7 on the effects of disturbance. The simplest way to measure diversity is the number of species found in a sample, called the species richness (S or SR). Yet diversity is not just about numbers of species; it is also concerned with the distribution of numbers of individuals per species. For example, if one assemblage has 50 individuals of each of 2 species A and B whereas another assemblage has 99 individuals of species A and 1 individual of species B, then both have the same species richness but the first assemblage is the more diverse. Thus a measure of diversity (an index) must take into account not only the number of species, but also the number of individuals per species. To distinguish this from species richness, the combination of individuals per species and number of species is called heterogeneity diversity. In fact there are a large number of diversity indices, and we do not propose to consider them all here (Magurran 2004 gives an excellent and detailed account and others are mentioned in the summary in Chapter 11).

scholarly journals Impact of Horizontal Edge–Interior and Vertical Canopy–Understory Gradients on the Abundance and Diversity of Bark and Woodboring Beetles in Survey Traps

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 573 ◽  
Author(s):  
Jon Sweeney ◽  
Cory Hughes ◽  
Vincent Webster ◽  
Chantelle Kostanowicz ◽  
Reginald Webster ◽  
...  
Keyword(s):  
Species Richness ◽  
Field Trapping ◽  
Horizontal Edge ◽  
Forest Gaps ◽  
Forest Insects ◽  
Trap Location ◽  
Abundance And Diversity ◽  
Species Richness And Abundance ◽  
The Impact ◽  
Gradient Effects

Semiochemical-baited intercept traps are important tools used to collect information about the presence/absence and population dynamics of forest insects. The performance of these tools is influenced by trap location along both horizontal edge–interior and vertical understory–canopy gradients. Consequently, the development of survey and detection programs requires both the development of effective traps and semiochemical lures but also deployment protocols to guide their use. We used field trapping experiments to examine the impact of both horizontal edge–interior and vertical understory–canopy gradients and their interactions with the species richness and abundance of Buprestidae, Cerambycidae and Curculionidae. Both gradients had significant effects on the diversity and abundance of all three families collected in traps and the pattern of gradient effects differed between the two experiments. In the first experiment, traps were deployed along transects involving large (>100 m) forest gaps and in the second experiment traps transected small (ca. 15 m) forest gaps. These results were consistent with the idea that gradient effects on the abundance and diversity of these three families of forest Coleoptera are context dependent. The results of this study suggest that monitoring programs for bark and woodboring beetles should deploy traps at multiple locations along both vertical understory–canopy and horizontal edge–interior gradients.

scholarly journals Species Diversity, Distribution and Abundance of Fishes of Seti Gandaki River Basin, Pokhara, Nepal

2020 ◽  
pp. 5-14
Author(s):  
Kishor K. Pokharel ◽  
Khadga B. Basnet ◽  
Trilok C. Majpuria ◽  
Chitra B. Baniya
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
River Basin ◽  
Environmental Variables ◽  
Diversity Indices ◽  
Urban Site ◽  
Abundance And Diversity ◽  
Study Sites ◽  
Urban Sites ◽  
Tor Tor

Species diversity with indices, distribution and abundance of fishes of Seti Gandaki River Basin, Pokhara, Nepal are described from five study sites, three along the main channel and two in major tributaries. Fishes were sampled using a cast-net following pass-removal method. Environmental variables were determined following the standard methods. In total, 30 species belonging to five orders, nine families and 24 genera with absolute abundance of 10,659 were recorded. A longitudinal pattern of distribution and species richness from upstream to downstream sites (17 to 21 species) was observed. Cyprinids were dominant followed by silurids, balitorids, channids, mastacembelids, belonids and cobitids. Distribution pattern and abundance data showed that the species Tor tor, Tor putitora, Chaguninus chagunio, Barilius barila, Opsarius barna, Danio rerio, Lepidocephalichthys guntea, Parachiloglanis hodgarti and Amblyceps mangois were not common in the study area. The environmental variables such as depth, width, discharge and temperature showed effect upon species richness, abundance, distribution and diversity indices, which had lower values at upstream pre-urban sites than at downstream post-urban sites. A sharp decline in species richness, abundance and diversity indices at urban site (10 species) indicated urban influence.

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