scholarly journals Vegetation biomass and habitat selection by a newly introduced population of muskoxen in northern Quebec

Rangifer ◽  
1993 ◽  
Vol 13 (2) ◽  
pp. 71 ◽  
Author(s):  
René Nault ◽  
Carole Mathieu ◽  
Michel Crête
Keyword(s):  
Plant Species ◽  
Extreme Values ◽  
Habitat Type ◽  
Ground Cover ◽  
Aerial Photographs ◽  
Herbaceous Plant ◽  
Habitat Types ◽  
Wet Meadow ◽  
Similar Range ◽  
The Difference

Ground coverage by woody and herbaceous plant species and standing biomass of vegetation susceptible to being grazed upon were estimated in a 156 km2 area where 190 muskoxen were censused during the preceding autumn. Habitat use was estimated with droppings census. Six terrestrial habitat types were delineated on 1:32 000 aerial photographs and randomly sampled: low shrub on xeric sites (LSX; 64 km2), low shrub on mesic sites (LSM; 45 km2), bare ground (BG; 27 km2), forest-tundra (FT; 12 km2), wet meadow (WM; 2 km2) and riparian willows (RW; 1 km2). Dominant plant species varied greatly between habitat types, and only a few such as Betula glandulosa, Salix arctophila, and Polygonum viviparum were common. Tall shrubs were present only in RW where they covered most of the ground, and in FT. Low shrubs were uniformly distributed and covered 18-32% of the ground, with the exception of RW (5%). Ground cover by herbs had a similar range (i.e. 20-37%), except in RW where the mean exceeded 50%. Mosses and lichens occupied about half of the ground everywhere. Phytomass exhibited great variation within and between habitat types; extreme values averaged 892 kg*ha-1 in LSX, and 1965 kg*ha-1 in LSM. However the difference was not significant due to limited sample size and within habitat variance. Nevertheless the mass of herbaceous dicots was greater in RW than in any other habitat type. Total phytomass was 2-20 times greater in northern Québec than in Greenland. Based on droppings density, muskoxen preferred RW over BG and FT, and LSX over BG. Although the density of muskoxen in the study area was high relative to other muskox ranges, habitat quality and quantity should allow continued population growth.

Remote Sensing of Chinese Tamarisk (Tamarix chinensis) and Associated Vegetation

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 273-278 ◽  
Author(s):  
J. H. Everitt ◽  
C. J. Deloach
Keyword(s):  
Plant Species ◽  
Aerial Photographs ◽  
Winter Period ◽  
Herbaceous Plant ◽  
Tamarix Chinensis ◽  
Color Film ◽  
Light Reflectance ◽  
Yellow Orange ◽  
Computer Analyses ◽  
Orange Color

Chinese tamarisk is an invader of riparian sites in the southwestern United States and northern Mexico. Plant canopy light reflectance measurements showed that Chinese tamarisk had higher visible (0.55- and 0.65-μm wavelengths and 0.63- to 0.69-μm waveband) reflectance than did associated woody and herbaceous plant species in the late fall-early winter period when its foliage turned a yellow-orange to orange-brown color prior to leaf drop. Chinese tamarisk had a yellow-orange color on conventional color (0.40- to 0.70-μm) aerial photographs during this phenological stage that made it distinguishable from other plant species. Computer analyses of conventional color film positive transparencies showed that Chinese tamarisk populations could be quantified from associated vegetation. This technique can permit area estimates of Chinese tamarisk infestations on wildland areas.

A system using aerial photography to estimate area of root disease centers in forests

1978 ◽  
Vol 8 (2) ◽  
pp. 214-219 ◽  
Author(s):  
Ralph E. Williams ◽  
C. D. Leaphart
Keyword(s):  
Large Scale ◽  
Habitat Type ◽  
Root Disease ◽  
Aerial Photographs ◽  
National Forest ◽  
Forest Land ◽  
Habitat Types ◽  
Coeur D'alene ◽  
Commercial Forest ◽  
Northern Idaho

The area of root disease centers on the Coeur d'Alene National Forest in northern Idaho was effectively estimated from large-scale color infrared aerial photographs. An estimated 5.1% (12 160.7 ha) of the commercial forest land was occupied by infection centers. Root disease centers were identified in 113 of 364 stands actually surveyed. Although most of these 113 stands were of the Tsugaheterophylla – Pachistimamyrsinites habitat type, the highest percentage of stands with root disease was found in the Abiesgrandis – Pachistimamyrsinites habitat type.Observations made during these studies suggest that occurrence of Pseudotsugamenziesii (Mirb.) Franco, Abiesgrandis (Dougl.) Lindl., or both in a stand is the most important factor in the expression of root disease centers. Accuracy of interpretation of photographs was 92%; incorrect interpretations were consistently associated with stands in the Abieslasiocarpa series of habitat types or with stands stocked with conifers tolerant of root pathogens.

Habitat use by sympatric female mallards and American black ducks breeding in a forested environment

1994 ◽  
Vol 72 (9) ◽  
pp. 1538-1542 ◽  
Author(s):  
Chris P. Dwyer ◽  
Guy A. Baldassarre
Keyword(s):  
New York ◽  
Habitat Use ◽  
Habitat Type ◽  
Home Ranges ◽  
Habitat Types ◽  
Black Duck ◽  
Disturbed Areas ◽  
Forested Areas ◽  
American Black ◽  
The Difference

There has been much speculation regarding whether breeding mallards (Anas platyrhynchos) and American black ducks (A. rubripes) use similar habitat types in forested areas, which could lead to increased interspecific contact. To study this issue, we used radiotelemetry during 1990–1991 on sympatric female mallards and black ducks breeding in the western Adirondack Mountains of New York. Mallard and black duck pairs occupied the general area at a density of 0.7 and 0.6/km2, respectively. Black duck home ranges tended to be larger than those of mallards, although the difference was not significant. Habitat composition within the home ranges of mallards and black ducks was similar, upland forest being the dominant habitat type, followed by wetlands, disturbed areas, and active residential sites. Within home ranges, mallards and black ducks were similar in their use of four major wetland habitat types. Our data suggest that undisturbed forest and habitat use within such areas may not serve as an isolating mechanism between breeding mallards and black ducks.

Advances in Fisheries Bioengineering

2008 ◽  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
Habitat Type ◽  
Strain Rates ◽  
Habitat Types ◽  
Drift Feeding ◽  
Velocity Gradients ◽  
The Difference ◽  
Lateral Scale

Abstract<em>.</em>—Focal positions of drift-feeding salmonids are often proximate to higher velocities and may be characterized by velocity gradients. Velocity gradients result in distortion of the flow field through linear deformation and angular deformation, which are summarized as the normal and shear strain rates, respectively. The objective of our study was to use a metric termed the exposure strain rate to quantify velocity gradients used by juvenile spring Chinook salmon <em>Oncorhynchus tshawytscha </em>across habitat type, seasons, and spatial scales. Within a habitat type, focal and mean water column velocities were measured at the position of each fish. In addition, mean column velocities were measured 0.6 and 1.2 m laterally toward the center of the channel. Three exposure strain rates were calculated as the difference between focal and mean column velocity in the vertical scale and at 0.6 and 1.2 m lateral scale divided by the length of the smallest fish (0.4 cm) length scale for all seasons and habitat types. This allowed direct comparison of exposure strain rates for all sizes of fish. The data revealed that for Chinook salmon larger than 4 cm, the distribution of vertical exposure strain rates was similar across all habitat types by season. Exposure strain rates began to vary between habitat types for the lateral scale, reflecting hydraulic differences between reach-scale habitat features. We concluded that juvenile Chinook occupied a specific shear environment independent of reach-scale habitat. Exposure strain rates described microhabitat use in a manner reflecting the habitat occupancy model for drift-feeding salmonids. For this reason, exposure strain rates provide more specific information on habitat use than focal velocities alone.

scholarly journals Plant species diversity of the wet meadows under natural and anthropogenic interventions: The case of the Lakes Amvrakia and Ozeros (W. Greece)

2021 ◽  
Vol 49 (3) ◽  
pp. 12435
Author(s):  
Anastasios ZOTOS ◽  
Chariklia KOSMA ◽  
Vassilios TRIANTAFYLLIDIS ◽  
Ioanna KAKABOUKI ◽  
George KEHAYIAS ◽  
...  
Keyword(s):  
Plant Species ◽  
Habitat Preferences ◽  
Natura 2000 ◽  
Life Forms ◽  
Ecological Value ◽  
Habitat Types ◽  
Wet Meadow ◽  
Total N ◽  
Wet Meadows ◽  
Natural Lakes

The Lakes Amvrakia and Ozeros (W. Greece) belong to the western chain of Greek wetlands running along the coast of the Ionian Sea. They are both natural lakes belonging to the Natura 2000, Site of Community Importance (pSCI) and are characterized by high ecological value. Wet meadows are typical habitat types of these wetland ecosystems which are in contact with rural ecosystems which they interact with. Due to the high conservation value of these habitat types, in the framework of this study the flora of the wet meadows was recorded and a floristic analysis concerning chorology, life forms and habitat preferences was made. A total number of 152 taxa was found in the wet meadows of both lakes from which only 47 taxa were common. The families with the greatest number of species were Fabaceae (22 taxa), Asteraceae (14 taxa) and Poaceae (9 taxa) for the wet meadow vegetation of the Lake Amvrakia and Fabaceae, Poaceae (17 and 13 taxa, respectively) for the Lake Ozeros. In both lakes the prevalence of the Therophytes is evident, while the life forms of Chamephytes and Aquatics were absent from the Lake Amvrakia. From the results of the canonical correspondence analysis among species, sampling plots and selected environmental variables, a clear separation between species and sampling plots was found, presenting strong correlation with specific edaphic parameters (pH, CaCO3, EC, , Total N, SOC and ). These edaphic properties, as a result of natural and anthropogenic interventions, seem to play an important role in the wet meadows plant species distribution pattern.

scholarly journals Do the assemblages of benthic macroinvertebrates in nearshore waters of Western Australia vary among habitat types, zones and seasons?

2005 ◽  
Vol 85 (2) ◽  
pp. 217-232 ◽  
Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Habitat Type ◽  
Abundant Species ◽  
Subtidal Zone ◽  
Habitat Types ◽  
Environmental Characteristics ◽  
Deposit Feeding ◽  
Number Of Individuals

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.

scholarly journals The phenobs initiative – A standardised protocol for monitoring phenological responses to climate change using herbaceous plant species in botanical gardens

2021 ◽  
Author(s):  
Birgit Nordt ◽  
Isabell Hensen ◽  
Solveig Franziska Bucher ◽  
Martin Freiberg ◽  
Richard B. Primack ◽  
...  
Keyword(s):  
Climate Change ◽  
Plant Species ◽  
Herbaceous Plant ◽  
Botanical Gardens

scholarly journals Phytoremediation Potential of Native Herbaceous Plant Species Growing on a Paradigmatic Brownfield Site

2021 ◽  
Vol 232 (7) ◽  
Author(s):  
N. Matanzas ◽  
E. Afif ◽  
T. E. Díaz ◽  
J. R. Gallego
Keyword(s):  
Plant Species ◽  
Contaminated Soils ◽  
Native Species ◽  
Low Cost ◽  
Plantago Lanceolata ◽  
Herbaceous Plant ◽  
Plant Interactions ◽  
Aerial Parts ◽  
Medicago Lupulina ◽  
Icp Ms

AbstractPhytomanagement techniques using native species allow the recovery of contaminated soils at low cost and circumvent the ecological risks associated with the use of non-native species. In this context, a paradigmatic brownfield megasite highly contaminated by As and Pb was sampled in order to analyze soil–plant interactions and identify plant species with phytoremediation potential. A survey was first carried out in a 20-ha area to obtain an inventory of species growing spontaneously throughout the site. We then performed another survey in the most polluted sub-area (1 ha) within the site. Pseudototal concentrations of contaminants in the soil, aerial parts of the plants, and roots were measured by ICP-MS. A detailed habitat classification was done, and a specific index of coverage was applied by means of a 1-year quadrat study in various sampling stations. Results converged in the selection of six herbaceous species (Dysphania botrys, Lotus corniculatus, Lotus hispidus, Plantago lanceolata, Trifolium repens, Medicago lupulina). All of these plants are fast-growing, thereby making them suitable for use in phytostabilization strategies. Furthermore, they are all easy to grow and propagate and are generally self-sustaining. All six plants showed accumulation factors below 1, thus revealing them as pseudomethallophytes and excluders. However, L. hispidus and M. lupulina showed translocation capacity and are considered worthy of further study.

scholarly journals Recent Invasion of the Endemic Banggai Cardinalfish, Pterapogon kauderni at The Strait of Bali: Assessment of the Habitat Type and Population Structure

2019 ◽  
Vol 24 (1) ◽  
pp. 15 ◽  
Author(s):  
I Nyoman Giri Putra ◽  
I Dewa Nyoman Nurweda Putra
Keyword(s):  
Natural Habitat ◽  
Habitat Type ◽  
Marine Organisms ◽  
Aquarium Trade ◽  
Small Populations ◽  
Depth Range ◽  
Habitat Types ◽  
Weight Relationship ◽  
Narrow Bay ◽  
Sexually Mature

The demands of marine organisms for the aquarium trade are remain high and seems continue to increase. Consequently, many of marine organisms has been spread out from its natural habitat as in the case of endemic Banggai cardinalfish, (Pterapogon kauderni). That has invaded “new” habitat since it being trade in 1995. In recent years, a small populations of P. kauderni is known to be exist in a narrow bay near the Gilimanuk harbor, Bali. An underwater visual fish census survey was conducted on June 2018 to estimate the habitat types and densities of P. kauderni.  Additionally, 23 specimens of P. kauderni were collected randomly in order to assess biological parameters such as the length-weight relationship. We successfully recorded 30 groups of P. kauderni that inhabit a shallow areas with a depth range between 0.5m to 2m. Of these, more than 90% of the groups were found to be associated with sea urchin (Diadema sp.) while the rest were found to live together with branching coral (Acropora sp.) and branching sponge (Ptylocaulis sp.). Total number of fish observed during the survey were 381 individuals. The fish density is 0.76 individu.m-2. Length-weight relationship showed that P. kauderni exhibit is negative allometry (b<3) which mean that the increase in length is faster than the weight gain. Interestingly, from the 23 specimens collected, none of these were sexually mature (SL<41 mm) which may indicated that the population of P. kauderni in Bali are under serious threats of exploitation.     

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