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1.
A new linyphiid spider, Palliduphantes elburz, sp. n., is described, based on material of both sexes taken from high altitudes in the Elburz Mts, northern Iran. The male of the new species is easily distinguished not only from the single Iranian congener, P. sbordonii (Brignoli, 1970), but also from other species of the genus by the strongly modified palpal tibia, the peculiar shape of the lamella characteristica, as well as the form and armature of the embolus. The epigyne of P. elburz, sp. n. seems to be most similar to P. stygius (Simon, 1884) from the western Mediterranean, but differs well by the much longer stretcher.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:E10F35CE-47D2-4FF8-9386-A00F3E61659B  相似文献   


2.
In the foothills of the Philip Smith Mountains, Brooks Range, Alaska, tussock tundra is the most widely distributed vegetation, and it occurs on rolling hills and in valleys that were shaped by a sequence of Pleistocene glaciations. In this study, aboveground standing biomass and production were compared in "intertrack tundra" areas that were relatively homogenous with respect to downslope drainage and adjacent "water tracks" that acted to channel water flow to the valley bottom stream. Comparisons of biomass, leaf area index, and specific leaf weight were also made between upper and lower slope positions. Similarities and differences of vegetation structure are examined with respect to graminoid, deciduous shrub, evergreen shrub, herbaceous, and bryophyte components.
Water tracks were found to have 1.5–1.7 times the biomass of intertrack tundra, and production (excluding secondary growth) in water tracks was 40% greater than in intertrack tundra. The aboveground biomass for all areas studied and the annual production values were similar to those found in other studies of tussock tundra. While only slight differences in depth of thaw occurred in water tracks and intertrack tundra during June and early July, water tracks thawed more deeply with the onset of summer rains. Warmer temperatures at 40 cm depth in July and August may have increased nutrient availability, whereas greater rooting depth and movement of water may have increased nutrient capture in water tracks as compared with the intertrack areas. Greater biomass and a deeper thaw depth occurred at upper slope locations.  相似文献   

3.
Summary In the foothills of the Philip Smith Mountains, Brooks Range, Alaska, tussock tundra occurs on rolling hills and in valleys that were shaped by Pleistocene glaciations. During the 1986 and 1987 summer seasons, Sphagnum growth and production were determined in water tracks on tundra slopes that acted to channel water flow to the valley bottom stream and in intertrack tundra areas that were relatively homogeneous with respect to downslope drainage. Measurements were made under ambient environmental conditions and on mosses receiving supplemental irrigation in each area. Growth rate for Sphagnum spp. (cm shoot length increase/day) was low and relatively constant in intertrack tundra and highest but quite variable in water tracks. A strong negative correlation was found between Sphagnum spp. growth rate and solar irradiance in the shady environment below Salix canopies in the water tracks. Estimates of net annual dry weight (DW) production for Sphagnum spp. ranged from 0.10 g DW dm-2 yr-1 in intertrack tundra vegetation to 1.64 g DW dm-2 yr-1 in well-shaded water tracks. Experimental water additions had little effect on growth and production in intertrack tundra and well-developed water tracks, but significantly increased growth in a weakly-developed water track community. Low production over large areas of tundra slopes may occur due to presence of slow growing species resistant to dessication in intertrack tundra as opposed to rapidly growing less compact species within the limited extent of water tracks. We hypothesize that species capable of rapid growth occur also in weakly-developed water tracks, and that these are water-limited more often than plants occurring in well-developed water track situations. Where experienced, high light intensity may additionally limit growth due to photoinhibition.  相似文献   

4.
Summary In tussock tundra areas of the foothills north of the Brooks Range, Alaska, up to two-thirds of annual precipitation may occur during intermittent summer thunderstorms. The seasonal pattern in capitulum water content of Sphagnum spp. depends on the frequency and duration of these precipitation events, on the microtopography of the habitat including depth of thaw, and on morphological characteristics of the individual species. The response of net photosynthesis to varying water content in Sphagnum squarrosum and S. angustifolium growing under willow canopies in a tussock tundra area near the Dalton Highway on the North Slope of Alaska was examined in the field. After a period in June required to develop photosynthetic capability, capitula water content was essentially optimal for photosynthesis in the range from 6 to 10 g H2O/g DW. Above this range, the rate of CO2 uptake was reduced, presumably due to limitations on CO2 diffusion to the photosynthetically active sites. At water contents below the optimum, net photosynthesis fell rapidly until reaching compensation at approximately 1 g H2O/g DW. Dependent on changes in weather conditions, average water content of Sphagnum samples collected in the field occasionally fell below 5 g H2O/g DW. During a particularly dry period, water content of individual Sphagnum hummocks fell below 1 g H2O/g DW, indicating that water stress does limit Sphagnum photosynthetic production in this habitat.  相似文献   

5.
The preparation of probability distribution maps is the first important step in risk assessment and wildfire management. Here we employed Weights-of-Evidence (WOE) Bayesian modeling to investigate the spatial relationship between historical fire events in the Chaharmahal-Bakhtiari Province of Iran, using a wide range of binary predictor variables (i.e., presence or absence of a variable characteristic or condition) that represent topography, climate, and human activities. Model results were used to produce distribution maps of wildfire probability. Our modeling approach is based on the assumption that the probabilities reflect the observed proportions of the total landscape area occupied by the corresponding events (i.e., fire incident or no fire) and conditions (i.e., classes) of predictor variables. To assess the effect of each predictor variable on model outputs, we excluded each variable in turn during calculations. The results were validated and compared by the receiver operating characteristic (ROC) using both success rate and prediction rate curves. Seventy percent of fire events were used for the former, while the remainder was used for the latter. The validation results showed that the area under the curves (AUC) for success and prediction rates of the model that included all thirteen predictor variables that represent topography, climate, and human influences were 84.6 and 80.4%, respectively. The highest AUC for success and prediction rates (86.8 and 84.6%) were achieved when the altitude variable was excluded from the analysis. We found slightly decreased AUC values when the slope-aspect and proximity to settlements variables were excluded. These findings clearly demonstrate that the probability of a fire is strongly dependent upon the topographic characteristics of landscapes and, perhaps more importantly, human infrastructure and associated human activities. The results from this study may be useful for land use planning, decision-making for wildfire management, and the allocation of fire resources prior to the start of the main fire season.  相似文献   

6.
Upper Permian (Murghabian) sponges from the Surmaq Formation exposed in the Hambast Mountains, south of Abadeh, central Iran are described. The sponge fauna of the Surmaq Formation is composed of at least 26 taxa, including 12 species of sphinctozoans, 12 species of inozoans, one operculospongid, and one lithistid species. The following taxa were determined to genus or species level: Sphinctozoa: Family Sebargasiidae: Amblysiphonella hambastensis n. sp., Discosiphonella iranica n. sp., Family Colospongiidae: Colospongia cortexifera Senowbari-Daryan and Rigby, Exaulipora permica (Senowbari-Daryan), Platythalamiella sp. 1, Platythalamiella? sp. 2, Parauvanella minima Senowbari-Daryan, Colospongia? or Neoguadalupia? sp., Family Guadalupiidae: Cystothalamia surmaqensis n. sp., Imbricatocoelia cf. paucipora Rigby, Fan and Zhang, Family Thaumastocoeliidae: Sollasia ostiolata Steinmann, Family Cryptocoeliidae: Stylocoelia circopora Wu. Inozoa: Family Peronidellidae: Preperonidella cf. Preperonidella recta grossa (Wu), Heptatubispongia symmetrica Rigby and Senowbari-Daryan, Hambastella sincassa n. gen., n. sp., Hambastella cumcassa n. sp., Family Maeandrostiidae: Maeandrostia kansasensis Girty, Maeandrostia? dubia n. sp., Surmaqella pustulata n. gen., n. sp., Family Auriculospongiidae: Pseudopalaeoaplysina huayingensis Wang, Qiang and Zhang, Family Disjectoporidae: Disjectopora beipeiensis Fan, Rigby and Zhang, Lichuanopora cf. bancaoensis Fan, Rigby and Zhang, Family Khmeriidae: Imilce newelli Flügel. Lithistida: Family Astylospongiidae: Raanespongia iranica n. sp. Among the sphinctozoans A. hambastensis n. sp. is an extremely abundant species. Among the inozoans the genus Hambastella n. gen., with both species, is the most abundant genus. The genera Disjectopora, Lichuanopora, and Pseudopaleoaplysina, were described as hydrozoans by early workers, but are assigned to the inozoans in this paper. The Upper Permian sponge fauna, as well as the composition of other reef organisms, from the Hambast Mountains in central Iran is different from that of the assemblage in the Lower Permian reefal limestones of Bagh-e Vang from the Shotori Mountians (northeast Iran).  相似文献   

7.
Calcareous algae of the Permian Jamal Formation were studied in three sections of the Shotori Mountains, located in northeastern Iran. In this paper, four genera including Imperiella Elliott and Süssli, Nanjinoporella Mu and Elliott, Tabasoporella nov. gen., and Pseudotabasoporella nov. gen. are described from the Howz-e Dorah locality, which is exposed about 2 km northeast of the type section of Jamal Formation in Mount Jamal. Tabasoporella nov. gen. is characterized by metaspondyl arrangement of phloiophore and wine-glass-shaped laterals with a stalk grouped to tufts. The individual tufts are separated by a ring-like cavity appearing as triangular, oval, or trapezoid in longitudinally dissected section. The arrangement and shape of the laterals in Pseudotabasoporella nov. gen. is similar to Tabasoporella nov. gen., but there are no cavities between the tufts. All four genera are highly developed and limited to the Permian period. They disappear at the end of Permian and are not found in the Triassic sediments. Until today, two species of Imperiella are found in Iran and Afghanistan. I. iranica Elliott and Süssli was described only from the Ruteh Formation of Alborz Mountains in north Iran and I. afghanica was described from the Permian of Afghanistan. The Jamal Formation of the Shotori Mountains is the second locality where both species are discovered. Moreover, species I. crassiparietalis and I. gracilis are the two new species described here. The genus Nanjinoporella—with type species N. pagoda Mu and Elliott—was known from the Permian (Artinskian) Chishia Formation of Nanjing, China. We describe the new species Nanjinoporella iranica from the Permian Jamal Formation of the Shotori Mountains, northeast Iran.  相似文献   

8.
9.
Summary Photosynthetic characteristics of three species of Sphagnum common in the foothills of the Brooks Range on the North Slope of Alaska were investigated. Generally, light-saturated rates of net photosynthesis decreased in the order S. squarrosum, S. angustifolium, and S. warnstorfii when plants were grown under common growth chamber conditions. For field-grown S. angustifolium, average light compensation point at 10°C was 37 mol m-2s-1 photosynthetic photon flux density (PPFD), and light saturation occurred between 250 and 500 mol m-2 s-1. At 20°C, compensation point increased to 127 mol m-2s-1 and the PPFD required for light saturation increased to approximately 500 mol m-2s-1, while maximum rates of CO2 uptake increased only slightly. Light response curves of chamber-grown plants exhibited substantially lower compensation points and higher light-saturated rates of CO2 assimilation than field-grown material, due perhaps to a higher percentage of green, photosynthetically competent tissue. All three species exhibited broad responses to temperature, with optima near 20°C, and maintained at least 75% of maximum assimilation between approx. 13° and 30°C. Rates at 5°C were approx. 50% of maximum. Studies of the microclimate of Sphagnum at the field research site suggest that CO2 uptake should occur at near light-saturated rates during the day in open tussock tundra but that PPFD may often be limiting under Salix and Betula canopies in a water track drainage. Simulations using a simple model provided a seasonal estimate of 0.78 g dry weight (DW) of S. angustifolium produced from each initial g of photosynthetic tissue under willow canopies, assuming no water limitations. Although the simulation model suggests that production would be 66% higher in open tussock tundra, S. angustifolium is rarely found in this potentially more stressful habitat. To explain the relative abundance of Sphagnum in shaded water track areas as compared to open tussock tundra, we postulate that the vascular plant canopies provide protection from adverse effects of high temperatures, excess irradiance and reduced water availability. Under conditions of normal water availability, removal of the vascular plant cover did not affect the tissue water content of S. squarrosum, but resulted in a strong decrease in photosynthetic capacity, accompanied by chlorophyll bleaching. These results suggest that photoinhibition may limit production under certain conditions.  相似文献   

10.
Fire is one of the main threats facing the long‐term survival of the forests in the Eastern Arc Mountains. Yet, our understanding of how it affects fauna, particularly birds, is still poor. A fire that originated on surrounding farmland burned approximately half of Kimboza Forest Reserve between 13 and 15 October 2010. To better understand how birds respond to fire, a short‐term study of understorey bird diversity and abundance in this forest reserve was conducted by comparing burned and unburned sites twenty months post‐fire. Capture rates were significantly higher at the unburned site compared to the burned site. Bird species diversity was also higher at the unburned site than at the burned site. Despite the brevity of the study, the results suggest that fire has negative effects on forest avifauna and forest fires need to be prevented at Kimboza Forest Reserve as they affect the distribution and diversity of understorey birds.  相似文献   

11.
We document Late Eocene vertebrate footprints from the Tarom Mountains of Iran that represent a significant addition to the record of proboscidean and perissodactyl footprints. These footprints are from sandstones and tuffaceous sandstones of strata equivalent to the Kond Formation that overlie middle Eocene sedimentary rocks and are overlain by Oligocene volcanics. The footprints are preserved at 16 tracksites from 10 distinct stratigraphic levels. The mammal footprints include the oldest known proboscidean tracks, assigned to Proboscipeda enigmatica Panin & Avram and to cf. Proboscipeda isp. Evident perissodactyl tracks are common, tridactyl footprints with distinct digit shapes and proportions assigned to the new ichnogenus and ichnospecies Moropopus elongatus. Footprints of small, hopping, rodent-like mammals are identified as Musaltipes taromi new ichnospecies. Other mammal footprints from the Tarom tracksites are indeterminate, and bird footprints are assigned to Avipeda isp. The Tarom tracksites document the oldest record of proboscidean footprints, and this indicates that proboscideans had reached the northern shore of Tethys by Late Eocene time. The abundance and distinctiveness of the Tarom perissodactyl tracks mirrors the abundance and diversity of moropomorph perissodactyls during the Middle-Late Eocene. The Tarom tracksites are the most extensive record of Eocene vertebrate footprints known from Iran.

http://zoobank.org/urn:lsid:zoobank.org:pub:F430F9DB-728F-4162-9791-DC2A5CC5ED43  相似文献   


12.
A long continuous trackway of a shorebird (cf. Charadriipeda) and a suite of possible Pantodonta (?Corophydon) or Dinocerata tracks are reported from the Eocene Karaj Formation. Fossil footprints are still rare in Iran, described only from two Jurassic and three Tertiary sites. Thus the current record, the third in the Teritary, adds to a sparse record and increases the diversity of known track types.  相似文献   

13.
Kiełtyk  Piotr  Delimat  Anna 《Plant Ecology》2019,220(1):1-12
Plant Ecology - The impact of exotic annual Impatiens glandulifera on invaded European vegetation is ambiguous; there are studies reporting considerable negative as well as weak or even no impact...  相似文献   

14.
The Permian bryozoan fauna of the Surmaq Formation exposed in a section near Kuh-e Hambast (Hambast Mountains, central Iran) includes ten species. Four species (Fistulipora sawatai Sakagami 1999, Fistulipora takauchiensis Sakagami 1961, Fistulipora monticulosa Nikiforova 1933, and Eridopora parasitica, Waagen and Wentzel 1886) indicate a Middle Permian (Murgabian) age of the formation. Six additional taxa, three cystoporates Fistulipora sp. 1, Fistulipora sp. 2, and Fistuliporidae gen. et sp. indet., as well as three trepostomes Dyscritella sp., Trepostomata gen. et sp. indet. 1 and Trepostomata gen. et sp. indet. 2 could not be identified at the genus and species level. The investigated fauna refers to the Middle Permian of Thailand, Pakistan, Indonesia, and Japan.  相似文献   

15.
The first blind, and colourless, noemacheiline cobitid fish is described and compared with other cave-dwelling species of the subfamily. The new taxon, recently discovered in a natural well connected with subterranean waters in the Zagros Mountains of Iran, coexists with the blind depigmented cyprinid fish Iranocypris typhlops discovered in 1937. Some consideration is given to the generic status of the new species and its relationships to other noemacheilines.  相似文献   

16.
A 19 m thick package of well-sorted lowermost Jurassic (Hettangian-Lower Sinemurian?) sandstones within the Shemshak Formation of the southeastern Alborz Mountains displays features characteristic of foreshore to upper shoreface environments such as tabular bedding, low-angle lamination, trough cross-stratification, parting lineation, and oscillation ripples. In contrast to most other beach successions recorded in the literature the sandstones contain a trace fossil assemblage characterised by low abundance but comparatively high diversity. The assemblage, comprising 14 ichnotaxa, is dominated by Palaeophycus heberti, Rhizocorallium irregulare, Gyrochorte comosa, and Parahaentzschelinia surlyki. Contrary to predictions, which assume a dominance of suspension-feeders in such high-energy environments, the trace fossil assemblage represents a variety of ethological groups ranging from suspension-feeders to deposit-feeders, detritus-feeders, scavengers, and a possible trap constructor (Ctenopholeus), whereby deposit-feeders predominate. This anomaly is explained by a high amount of organic detritus in the sediment, indicated by abundant plant material, and a position of the beach in the vicinity of a river mouth.  相似文献   

17.
【背景】商业酵母的使用造成葡萄酒同质化问题严重,发掘优良本土酿酒酵母具有十分重要的意义。【目的】从168株宁夏本土酿酒酵母菌株中筛选出性能优良、具有出色葡萄酒发酵能力的菌株。【方法】基于杜氏管发酵试验和乙醇、高糖等耐受性试验分析产H2S能力及生长曲线测定的方法,筛选出发酵力好、耐受性强、低产H2S的本土酿酒酵母进行赤霞珠葡萄酒发酵试验,测定葡萄酒样基础理化指标、酚类物质和挥发性成分,探究筛选出的酿酒酵母发酵特性。【结果】初步筛选出发酵快速,能适应13%乙醇、350 g/L葡萄糖、250 mg/L SO2、pH 1.0的生存环境且低产H2S的4株本土酿酒酵母YC-E8、QTX-D17、QTX-D7、YQY-E18。菌株YC-E8产甘油能力强,所发酵酒样香气与商业酵母XR、F33最为接近,适用于赤霞珠葡萄酒的发酵。菌株QTX-D17发酵酒样中酒精、单宁、总酚和花色苷含量最高,表现出本土酿酒酵母优良的发酵特性。菌株QTX-D7所发酵酒样香气中乙酸乙酯、辛酸乙酯、1-壬醇等物质含量较高,赋予了葡萄酒香蕉味、苹果味、菠萝味、椰子味等愉悦花果香。【结论】最终筛选出3株优良本土酿酒酵母QTX-D17...  相似文献   

18.
Although nitrification has been well studied in coniferous forests of Western North America, communities of NH3-oxidizing bacteria in these forests have not been characterized. Studies were conducted along meadow-to-forest transects at two sites (Lookout and Carpenter) in the H. J. Andrews Experimental Forest, located in the Cascade Mountains of Oregon. Soil samples taken at 10- or 20-m intervals along the transects showed that several soil properties, including net nitrogen mineralization and nitrification potential rates changed significantly between vegetation zones. Nonetheless, terminal restriction fragment length polymorphism (T-RFLP) analysis of the PCR-amplified NH3 monooxygenase subunit A gene (amoA) showed the same DNA fragments (TaqI [283 bp], CfoI [66 bp], and AluI [392 bp]) to dominate ≥45 of 47 soil samples recovered from both sites. Two fragments (491-bp AluI [AluI491] and CfoI135) were found more frequently in meadow and transition zone soil samples than in forest samples at both sites. At the Lookout site the combination AluI491-CfoI135 was found primarily in meadow samples expressing the highest N mineralization rates. Four unique amoA sequences were identified among 15 isolates recovered into pure culture from various transect locations. Six isolates possessed the most common T-RFLP amoA fingerprint of the soil samples (TaqI283-AluI392-CfoI66), and their amoA sequences shared 99.8% similarity with a cultured species, Nitrosospira sp. strain Ka4 (cluster 4). The other three amoA sequences were most similar to sequences of Nitrosospira sp. strain Nsp1 and Nitrosospira briensis (cluster 3). 16S ribosomal DNA sequence analysis confirmed the affiliation of these isolates with Nitrosospira clusters 3 and 4. Two amoA clone sequences matched T-RFLP fingerprints found in soil, but they were not found among the isolates.  相似文献   

19.
In northern Shiraz (SW Iran), Lower Cretaceous carbonate was studied in detail. In this study, nine species of dasycladacea algae were classified. There are different species of dasycladacea algae which belong to seven different genera: Actinoporella, Cylindroporella, Dissocladela, Heteroporella, Neomeris, Salpingoporella, Trinocladus; one species of udoteaceae belongs to Bouenia; one species of acetabulariaceae belongs to Clypeina and the microproblematicum Coptocampylodon was also seen. Among the green algae, dasycladaceae and acetabulariceae are the most frequent and udoteaceans are rare in Zagros Mountains. The genus of Trinocladus is a new record for Lower Cretaceous (Upper Albian) in SW Iran.  相似文献   

20.
Lower Permian Bryozoan fauna of Jamal Formation, exposed in Bagh-e Vang (Shotori Mountains, northeast Iran) includes six species. Three species – Streblotrypa (Streblascopora) marmionensis (Etheridge 1926), Rhabdomeson bispinosum (Crockford 1944) and Alternifenestella kungurensis (Stuckenberg 1898) – indicate the Lower Permian (Artinskian to Kungurian) age of the formation. Three additional taxa – Fistulipora sp. 1, Fistulipora sp. 2 and undetermined timanodictyid bryozoan ?Timanodictya sp. could not be identified at the species level. The investigated fauna refers to Uralian and Australian palaeobiogeographic provinces.  相似文献   

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