Attached and planktonic algal communities in some inshore areas of Great Bear Lake

1980 ◽  
Vol 58 (21) ◽  
pp. 2294-2308 ◽  
Author(s):  
James W. Moore

The species composition and standing crop of epilithic, epipelic, and planktonic algae were determined in three widely separated inshore areas of Great Bear Lake during the summers of 1976, 1977, and 1978. The most frequently encountered diatoms in the epilithon were Tabellaria ftocculosa and Achnanthes minutissima regardless of location, whereas the predominant chlorophyte was Ulothrix zonata. These species were generally rare in the epipelon and were replaced in importance by Gyrosigma spenceri, Nitzschia obtusa, Cocconeis placentula, Amphora ovalis, and Achnanthes lanceolata, depending on sampling site. The densities of the epilithon and epipelon were low in June but increased gradually during the summer, reaching maxima of 78 × 107 and 120 × 107 μm3 cm−2, respectively (19.5 × 105 and 40 × 105 cells cm−2), in either August or September. These values are among the lowest recorded for fresh waters and are probably due to continually low water temperatures and wave action rather than nutrient limitation. The most important species in the plankton in all three sampling areas were Dinobryon bavaricum, Dinobryon sociale, Rhodomonas minuta, Cyclotella species, Synedra acus var. radians, and Ankistrodesmus falcatus. Plankton standing crops of up to 62 mg fresh weight m−3 were recorded in June at a temperature of 0 °C, and they increased to 70–91 mg m−3 (23.3 × 107−30.1 × 107 cells m−3) by September. These values are again among the lowest on record, a reflection of low water temperatures. The similarity in the species composition and standing crop of the plankton, epilithon, and epipelon in all collection areas was due to the similarity in water chemistry and temperature throughout Great Bear Lake.

2021 ◽  
Vol 13 (14) ◽  
pp. 8060
Author(s):  
Mehmet Ramazan Bozhuyuk ◽  
Sezai Ercisli ◽  
Neva Karatas ◽  
Halina Ekiert ◽  
Hosam O. Elansary ◽  
...  

The Rosa is one of the most diverse genera in the plant kingdom and, in particular, its fruits have been used for multiple purposes in different parts of the world for centuries. Within the genus, Rosa canina and Rosa dumalis are, economically, the most important species and dominate Rosa fruit production. In this study, some important fruit and shrub traits of ten Rosa canina and ten Rosa dumalis ecotypes collected from rural areas of Kars province, located in the east Anatolia region of Turkey were investigated. We found significant differences among ecotypes in most of the morphological and biochemical traits. The ecotypes were found between 1446–2210 m altitude. Fruit weight and fruit flesh ratio ranged from 2.95 g to 4.72 g and 62.55% to 74.42%, respectively. SSC (Soluble Solid Content), Vitamin C, total phenolic, total flavonoid, total carotenoid, and total anthocyanin content of the ecotypes ranged from 16.9–22.7%, 430–690 mg per 100 g FW (fresh weight), 390–532 mg gallic acid equivalent per 100 g FW, 0.88–2.04 mg per g FW, 6.83–15.17 mg per g FW and 3.62–7.81 mg cyanidin-3-glucoside equivalent per kg, respectively. Antioxidant activity was determined to be between 19.7–34.7 mg ascorbic acid equivalent per g fresh weight. Rosa ecotypes contained chlorogenic acid and rutin the most as phenolic compound. Our results indicated great diversity within both R. canina and R. dumalis fruits.


2018 ◽  
Vol 23 (11) ◽  
pp. 2087 ◽  
Author(s):  
Peng-Yu Jin ◽  
Lu Tian ◽  
Lei Chen ◽  
Xiao-Yue Hong

Understanding pest species composition and their geographic distribution of important spider mites is fundamental and indispensable to establish an integrated pest management program. From a long-term survey during 2008–2017 in mainland China, we found that Tetranychus truncatus was the most frequently sampled Tetranychus spider mite (48.5%), followed by T. pueraricola (21.2%), T. kanzawai (12.5%), T. urticae (red) (5.7%) and T. urticae (green) (4.5%). Among them, T. truncatus was the major mite pest in the north of China. T. kanzawai was the dominant species in the Middle and Lower Reaches of the Yangtze River Region and T. pueraricola was the most important species in the southwest region. Other common and serious pests include Amphitetranychus viennensis (6.8%) and Panonychus citri (3.8%). This pattern was largely different from that in 2002–2004, when T. urticae (green and red) was believed to be the most serious mite pest. The factors involved in the change of species composition are not clear and need more exploration. We suggested that the increasing corn planting range may be partly responsible for the conversion of dominant species from other spider mites to T. truncatus. Further research on the mechanisms underlying the change of dominant species will help develop integrated management strategies.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Diana Kharkongor ◽  
Papiya Ramanujam

The study deals with a comparative study on diversity and species composition of subaerial algal communities from tree barks of closed undisturbed sacred grove, mixed plantation, and open disturbed forest. A total of 85 taxa had been recorded, 30 cyanobacteria and 55 algal species belonging to six classes of algae. Sacred grove harboured the highest subaerial algal diversity compared to those of plantation and open disturbed forest. There was a strong significant difference in species composition among the three different sampling areas. High number of diatoms with 14 species was recorded in sacred grove. Cyanobacteria with 22 species were the frequent group in disturbed forest whereas Trentepohliales dominated in plantation. Canonical correspondence analysis confirmed that high photon irradiance favored the growth of cyanobacteria in disturbed forest. The abundance of Trentepohliales members correlated to high rainfall and photon irradiance. High diversity and presence of many diatom species in undisturbed Mawphlang sacred grove were associated with low photon irradiance and high relative humidity and could also be due to a presence of suitable substrata formed by the growth of mosses. Sunlight, relative humidity, and rainfall were the important factors which played a major role in determining the diversity and distribution of subaerial algal communities.


1991 ◽  
Vol 8 (4) ◽  
pp. 156-160
Author(s):  
Bruce G. Hansen ◽  
William G. Luppold ◽  
R. Edward Thomas

Abstract During the past decade, poor documentation and computer software containing outdated price parameters used to screen and "correct" data taken from U.S. export declarations resulted in significant overestimation of official U.S. hardwood lumber export volumes. In the year prior to their correction, U.S. hardwood lumber exports to Europe were about half the officially reported volume. Although official statistics indicated red oak was the most important species traded, the new data indicate that, in fact, white oak exports in 1988 were actually three times red oak exports. To provide a check on the official statistics and to revise previous export volume data, new estimates were developed using information taken directly from ship manifests. Not only have the ship manifest data provided a more accurate assessment of U.S./European trade, but they have provided new insights into the species composition and geographic source of U.S. exports as well. This paper uses the revised data to focus on three aspects of U.S./European trade--trade trends over the decade, species composition of U.S. hardwood lumber exports, and the origin of U.S. exports. North. J. Appl. For. 8(4):156-160.


1982 ◽  
Vol 60 (12) ◽  
pp. 3196-3205 ◽  
Author(s):  
Joseph B. Rasmussen

The heated area of Lake Wabamun prior to macrophyte harvesting had higher submerged macrophyte production, greater amounts of plant detritus in the sediment, and a higher standing crop of benthic macroinvertebrates than the unheated area. Species composition of the benthic macroinvertebrate community was also much different in the heated area with the warmest areas supporting a community dominated by tubificid oligochaetes (Limnodrilus hoffmeisteri and Tubifex tubifex), and the moderately heated areas supporting a community dominated by large Chironomus species (Chironomus plumosus and Chironomus atroviridis). Benthos of the unheated parts of the lake consisted mainly of smaller chironomid species such as Chironomus maturus, C. (cf.) staegeri, Polypedilum nubeculosum, Cladotanytarsus spp., and Tanytarsus spp. The heated area was subjected to mechanical macrophyte harvesting which removed the majority of the submerged macrophytes. This reduced the amount of plant detritus within the sediment and also the standing crop of benthic macroinvertebrates in the heated area. Species composition of the oligochaete-dominated community was not affected by harvesting. Species composition of the Chironomus-dominated area was greatly affected by harvesting and became more similar to that of the unheated area; densities of the large Chironomus species were reduced to low levels, while the densities of smaller chironomid species increased.


2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Shiferaw Yalew ◽  
Bimrew Asmare ◽  
Yeshambel Mekuriaw

Abstract. Yalew S, Asmare B, Mekuriaw Y. 2020. Effects of fertilizer type and harvesting age on species composition, yield, and chemical composition of natural pasture in the highlands of Ethiopia. Biodiversitas 21: 4999-5007. The experiment was conducted to evaluate the effects of fertilizer type and harvesting age on species composition, yield, and chemical composition of natural pasture in the highlands of Ethiopia. The experiment was laid out in randomized complete block design with factorial arrangement of two factors (fertilizer and harvesting age) with five replications. The data collected from the current study were forage species composition, dry matter yield, and chemical composition of natural pasture at different ages of harvesting. Forage species composition was determined by taking representative samples and identifying species from each sampling site. The samples of natural pasture were harvested at 90 and 120 days of age, weighed, dried, and then ground after that subsamples were taken for analyses of dry matter (DM), crude protein (CP), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF) and acid detergent lignin (ADL). All the collected data were subjected to GLM ANOVA procedures of SAS version 9.0. The result indicated that all species composition and dry matter yield were significantly affected (P<0.001) by fertilizer type and harvesting ages. Higher forbs (0.66%) were found in control plot at 90 days of harvesting age. Natural pasture harvested at 120 days of harvesting and urea fertilizer application results the highest dry matter yield (DMY) (8.26 t/ha) while the lowest level (3.20 t/ha) from unfertilized plot at 90 and 120 days of harvesting. The relative proportion of legumes in the natural pasture attained its climax stage at 90 days while grass attained at 120 days of harvesting. The highest mean DMY (6.24 tone/ha) was obtained at 120 days of harvesting and the lowest (4.71 ton/ha) at 90 days of harvesting. Among the chemical composition parameters, DM, ash and CP were significantly affected (P<0.001) by both fertilizer type and harvesting age. The content of CP and ash were increased with manure fertilizer at early harvest age and were decreased with delayed harvest age. The application of fertilizer type did not significantly affect (P>0.05) NDF content of the natural pasture rather affected by stage of harvesting (P<0.001). Regardless of DM yield, better quality pasture was recorded for early (90 days) harvesting age and use of compost recommended for future natural pasture improvements as use of chemical fertilizer is relatively expensive for the majority of smallholder farmers in the highlands.


2018 ◽  
Vol 19 (4) ◽  
pp. 1326-1333 ◽  
Author(s):  
DURANTA D. KEMBAREN ◽  
ZAIRION ZAIRION ◽  
MOHAMMAD M. KAMAL ◽  
YUSLI WARDIATNO

Kembaren DD, Zairion, Kamal MM, Wardiatno Y. 2018. Abundance and spatial distribution of blue swimming crab (Portunuspelagicus) larvae during east monsoon in the East Lampung waters, Indonesia. Biodiversitas 19: 1326-1333. The blue swimmingcrab/BSC, Portunus pelagicus, is an economically important species in fishery industry and continuously being exploited, particularly inthe East Lampung waters. BSC research in Indonesia during the last decade was only restricted to the adult phase, while research ontheir larval dynamics in nature has not been done yet. This study aimed to assess the abundance and the distribution of BSC larvae, andto describe their correlation to its environmental conditions. This study was conducted in June 2017 (during east monsoon) in the EastLampung waters. Sampling was done in surface water during the daylight hours on nine sites with three replicates on each site. Planktonabundance and oceanographic profile were also recorded from the same sampling site. The result from this study showed that the waterquality from the environment was suitable for the development of BSC larvae. The abundance of the early-stage larvae (Z1-Z3) wasrelatively higher than the late-stage larvae (Z4 and M). The larval stages of BSC were dispersed and completed their development in themid-shore and offshore waters. There was a tendency that the early-stage was more abundant in the northern part, while the late-stagewas more abundant in the southern part of the study area. The highest larval abundance was found in the mid-shore, particularly in sitenumber five, which was influenced by the water mass density and current direction during the east monsoon. Moreover, oxygenconcentration and salinity of the water environment influenced the early-stage larvae abundance more than the late-stages abundance.


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