An investigation of the influence of drought and other soil factors on the structure of a calcareous grassland.

Previous experimental investigations (Grime & Curtis 1976; Hillier 1984), and long term climatic monitoring (Rorison et al 1986a,b) have revealed the frequent occurrence of drought during the summer period in calcareous grassland on the south-facing slopes of limestone dales in the Peak District of North Derbyshire, Northern England. The main objective of the studies in this thesis was to examine the role of drought as a determinant of the characteristics of one selected calcareous grassland system at Tongue End in Millersdale. Particular attention has been given to the interaction of drought with soil heterogeneity and mineral nutrient stress. Efforts have been made to differentiate between mechanisms of drought tolerance and drought avoidance, and this has allowed some assessment of the contribution of diversity in morphology, life history and physiology to the maintenance of species-richness in the vegetation at the site. Three complementary methods of investigation were adopted; (1) analysis of spatial patterns by grid sampling of the field site. (2) comparative study of 17 component species in standardized environments. (3) synthesis of plant communities in turf microcosms simulating certain aspects of the Tongue End habitats. In the final chapter (Chapter 8) an attempt is made to integrate results from the observations and experiments described in previous chapters. Evidence from the investigation suggests that on the south-facing slope at Tongue End, floristic diversity is maintained by naturally occurring phenomena, in which drought and low nutrient status interact with soil depth and rock exposure. These factors are responsible for high seedling mortality, gap creation and spatial heterogeneity. The hypothesis is formulated that (1) the species -rich community established on the south-facing slope at Tongue End contains an assemblage of plants most of which are attuned to both regular predictable disturbance and chronic nutrient-deficiency. (2) drought interacts with the mosaic in soil depth and rock exposure within the studied site; species with the potential to develop deep root-systems are locally prominent in circumstances where there is access to continuously moist subsoil

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Plant Species of Ponds and Springheads in Lorestan (Iran)

AbstractVegetation around springs and ponds causes water to re-infiltrate into the ground and recharge underground reservoirs. In the study of ponds and springs in Lorestan province, 108 species were identified which belong to 35 families and 64 genera. Depending on the habitat and life form, these species constitute emergent 41%, marginal 31%, floating 23%, and submerged 5%. Nuphar lutea were present in the habitat of the springhead of Niloufar and Potamogeton alpinus in the Gahar Lake and the Amir spring. Both habitats have cold and clear water with no contaminants. Typha latifolia is mostly found in Pol-e-Dokhtar tropical wetlands. The genera Carex, Cyprus, Juncus, Phragmites, Mentha, and Veronica were present in almost all wetland habitats and springs. In the springhead of Niloufar, where the pollutants are spread, Sparganium erectum and Sorghum halepense are highly concentrated but Nuphar lutea is very scattered. In most Peatlands, in addition to the marginal species, there was a perennial wild species called Hordeum brevisubulatum, which usually has spreading rhizomes. They were found in saturated and muddy soils. More than 81% of wetland species are present in more than one chorotype. In mountain springs and spring wetlands, endemic species of Rorippa kurdica were present but limited, probably due to dispersal barriers or special habitat conditions. Failure to pay attention to wetlands as storage sponges and water infiltration will lead to species extinction and ecological damage.IntroductionWetlands are responsible for charging underground water sources. Water, plant species, and soil are the main characteristics to determine the type of wetland. Plants of wetland (hydrophytes) must tolerate soil oxygen deficiency, potential waterlogging and drying, nutrient deficiency, low pH, high salinity, and other limiting factors. One of the important benefits provided by wetlands in improving water quality is filtering sediments and nutrients in surface water. The socio-economic values provided by wetlands are significant. Lorestan province is considered one of the poles of the country's water resources due to the diversity of its climate and the capabilities of its mountainous nature. The wetlands of Lorestan province can be divided into five main groups: 1) Ponds, 2) springs and wet meadows, 3) waterfalls, 4) mountainous and snowy wetlands, and 5) wetlands of the rivers of the province. This division in the hydrological rhythm has caused differences in the plant species of these regions. In order to preserve and prevent further destruction, identifying the flora of these wetlands and their environmental value is very important. Materials and MethodsTo prepare the floristic list, the conventional method of taxonomic studies and regional surveys was used. The location of the wetlands was identified and their exact location was recorded, and the geographic coordinates and height above sea level were determined using GPS. During different seasons from 2014 to 2018, plant specimens were collected, identified, pressed, and numbered which are deposited in the herbarium of Lorestan Agricultural and Natural Resources Research and Education Center. Vascular plants of the wetlands are classified according to Sculthorpe's (1967) idea into four groups of marginal, emergent, floating, and submerged. The chorotype of plant species was also determined by referring to different sources. ResultsIn the present study, 108 plant species belonging to 35 families and 64 plant genera were identified in the areas of Sarab-Niloufer, Sarab Amir, Sarab Zaz, Poldakhtar wetlands, Aligudarz, and Gahar Lakes. According to the habitat and type of life, emergent with 45 species (41.66 percent), marginal with 34 species (31.48 percent), submerged aquatic plants with 24 species (22.22 percent), and floating aquatic plants with 5 species (4.62 percent) were present in the study areas. Discussion and ConclusionOn the bases of the findings of the study, plant species of Lorestan wetlands, based on the growth method and physical relationship with water and soil, were categorized into four groups:1) Marginal species, moisture-loving: plants in this range are exposed to water level fluctuations on an intermittent or seasonal basis compared to the range of dryland plants. The following spices can be mentioned from this group: Sonchus maritimus L., Cirsium spectabile DC, Mentha longifolia (L.) Huds., Tussilago farfara L., Arctium lappa L., Equisetum ramosissimum Desf., Bellis perennis L. and Sisymbrium irio L. These species usually grow on the side of springs and meadows.2) Emergent plants: the most common species of this group were present in large monocot families that tend to dominate freshwater marshes. Among these families: Poaceae, Cyperaceae, Juncaceae and Typhaceae are worth mentioning.3) A group of floating plants: yellow lotus species (Nuphar lutea (L.) Smith), blue lentil (Lemna spp.), watercress (Nasturtium officinale R.Br.), and amphibious grass (Persicaria amphibia (L.) Gray) are among the floating species identified in the study areas.4) Submerged plants group: in the studied areas, the species of potamogeton alpinus, potamogeton crispus L., Utricularia minor L., hornwort (Ceratophyllum demersum L.), thousand leaves (Myriophyllum spicatum L.), Ruppia maritima L., and blue sedge (Batrachium trichophyllum (Chaix) Bosch) were identified. These plants are mostly under water. They are rarely seen by the public. Almost all of these plants had roots attached to the substrate. Submerged rooted species obtain the majority of nutrients they need from the bottom sediments.Finally, it was observed that soil erosion has increased in the areas where the springs and ponds have been destroyed, and also the severity of floods caused by seasonal rains is very high. In addition to this, wetlands are among the wealth-producing ecosystems in Lorestan province. Damaging the plant species of wetlands and drying them while removing their benefitscould cause environmental crises including turning them into centers of fine dust and creating dust

A new record of Solanum chenopodioides (Solanaceae), from Iran, Bujagh National Park (Guilan Province)

Solanum chenopodioides is introduced here as a new record for the flora of Iran from the coastal areas of the Caspian Sea, Guilan province. This species grows in Bujagh National Land-Sea Park, on sand dunes, along with other coastal psammophytic plants. This species belongs to the Morelloid clade. It differs from the related species S. nigrum, by its shrubby nature, perfect leaves margin, dull berries, bi-colored petals in the middle, and peduncle that bends a bit downwards in fruit. This plant is native to southern South America. It is introduced as a common weed all over the world; in addition, this species is considered an alien species for the flora of Iran. Transit of goods, especially wool, to the different parts of the world is one of the ways of the spread of this species all over the world. In addition to providing some pictures of the plant, some notes about the distribution and ecology of this species were also provided in this paper. The numerous reports of alien species from Bujagh National Park in recent years could be regarded as a credible warning for the stability of native vegetation of the area and existing ecosystems

Response of round-leaf ash (Fraxinus rotundifolia Mill.) leaves to urban pollutant gases

Air pollution is one the threatening factors affecting human and plants health in the cities. Since human continuance is closely related with the plants’ survival, different effects of pollution on plants can affect green areas and vegetation management and preservation in urban zones. Therefore, this study was carried out to define the effects of urban pollutant gases (SO2, NO2 and O3) on quantitative characteristics of round-leaf ash (Fraxinus rotundifolia Mill.) in Tehran. The study was carried out in seven municipal districts of Tehran, which were selected to include the wide spectrum of climatic conditions and contrasted levels of air pollution within the city. Quantitative characteristics including leaf area, specific leaf area, wet and dry weight, leaf toughness and thickness and water content percentage were studied by means of correlation analysis and t- test. The correlation results showed that increasing air pollution results in decreasing dry and wet weights and leaf area. Amongst the seven studied districts, the analysis revealed that Azadi and Sorkhehesar areas were associated with significant differences in pollution and non-significant differences in soil and climate. Our study indicated that all of the characteristics are significantly different in two areas. Furthermore, the quantities of all parameters except leaf thickness significantly decreased in more polluted areas

Introduction of some of the ecological and silvicultural Characteristics of the forest areas of Kermanshah province

Climate, plant and soil diversity during ecological development, resulted in complex ecosystems at Zagros zone of Iran. Different forest types diversity from north to south of Zagros, is a good evidence for that case. The importance and the critical role of this ecosystem on economical, social and environmental prospectives of the country, makes it essential to study and investigate the zone comprehensively. However, investigation on relationship between plant cover and the ecological factors which affect the zone, can lead to a better knowledge of the zone. In vestigation on tree, shrub and grass species autecology at these forest is highly important in order to identify forest distribution of the province according to climate diversity, the climate map (according to the important climate method of de Martonne) was matched with the topographical map of Iran, then controlled by forest walking. The tree, shrub and herb species characteristics and some of the edaphic and topographical parameters were studied using 126 macro plots (500 m2) and 630 micro plots (105 m2), the sampling plots were located on contour lines at loo m. altitude intervals. Overall, 13 forest sites at six climate types were identified, based on the applied research parameters, dominant slope direction and 1000 m. distance between the sample plots at each contour line, including: Bayangan & Gahvareh with cold humid climate, Islam – Abade – garb, Darbadam and Geomarg with semi – humid cold climate Tazehbad with very humid cold climate, Ghalajeh with semi humid ultra cold climate, Javanrood with 2 climate types; humid temperate and humid cold and finally five sites: Chaharzbar, Harrasam, Sarv -e- no, Sarpole - e - zahab and Qeymas with semi dry cold climate. Moreovoer, it was identified that: The greatest and the lowest density of the tree and shrub species belonged to Harrasam (semi – arid cold climate) and Galajeh (semi – humid ultra – cold climate), respectively. The highest and the lowest density of the seed origin forests, belonged to Tazeabad (very humid cold climate) and Sarv-e – no (semi – arid cold climate), respectively. The greatest and the lowest percentage of forest crown cover belonged to humid cold and humid temperate climates of Javanroud, respectively

Study on dormancy breakage and germination in three species of Hawthorn (Crataegus aminii,C. persica and C. babakhanloui)

Crataegus from Rosaceae family is a tree that has medical and ornamental applications. Seeds of this genus have germination problem and may not germinate for 2 to 3 years. There are limited information about germination of different species. Therefore, study on germination of three native species of Iran, Crataegus aminii,C. persica and C. babakhanloui is conducted and the most effective treatment was determined. To evaluate the germination and breaking seed dormancy of three species, an experiment was carried out as a completely randomized design with four treatments and three replications. Seeds were imposed under physical stimulator treatment, including, scarification and warmth followed by cold stratification. Results indicated that in all treatments, scarification is effective for permeability to water of seed coat and breakage of seed dormancy. Germination rate in treatment 4 (impose to running water for 24h, then 3 month warmth, followed by 4.5 month cold stratification) had the highest rate. The highest percentage of germination and vigor were in treatment 3 (sowing the seeds outdoors at the beginning of summer). The number of the seeds that have embryo in each fruit is determined. More than 80% of fruits have only one embryo

Environmental effects on leaf morphology traits in the populus euphratica Oliv. provenances of Iran

We studied the variation in leaf morphological traits for 7 habitats of Populus euphratica Oliv. in natural form as well as transplanted to an experimental station in Karadj- Iran. In this study, 28 even-aged, mature P. euphratica trees and 24 leaf samples were randomly collected from each habitat (6 leaves for each tree). Then a set of macro- and micro-morphological characteristics were measured on the samples. There was a plastic morphological response to the environment for each provenance. All morphological characters except maximum leaf width (MLW), ratio of petiole length to leaf length (PL: LL) and the distance between the middle of maximum leaf width and leaf blade (DLL) varied significantly among provenances in both natural and field conditions. Stomata density and stomata size were plastic characters, since the stomata density increased in warm habitats while stomata size decreased. In addition, we observed significant differences in size and density of stomata for natural and field-transplanted provenances. Correlation analysis between environmental factors and leaf morphological traits indicated a significant relationship. Furthermore, Principal component analysis (PCA) on all morphological traits on provenances showed that morphological range of the provenances decreases when growing in the experimental field compared to their natural habitat. Eventually, we found a weak significant correlation between geographical and morphological distances

Investigation on phenolory of different poplar clones in collection at Karaj research station during 1997 & 1998 period

The prerequist in planning and implementing any research project is possession of preliminary and basic data and information. Phenological information are required by researchers of various poplar trees research projects. The purpose of this study was to obtain and collect such essential information. In this study the phenology of 30 Poplar clones at Karaj collection during 1997 and 1998 were studied. Factors such as anthesis, foliation, seed ripeness, defoliation, daily minimum and maximum temperature at the site were considered. The results of this study may be summarized as follows: Living activity of various poplar clones starts in the period between early Mars until late April and ends up between middle of November until late December. The time difference of few days up to few weeks exist in the appearance of various life phenomenas. Initiation data for poplar living activities at the start of growth season depends on the daily temperature. Therefore due to the fact that mean, minimum and maximum temperature of early period of growth season in 1998 was higher than relevant temperature for 1997, life phenomenas of this year appeared one week earlier than 1997. However defoliation is mostly influeneced by photoperiod and minimum temperature and as a result of shortening the daylight time and dropping the temperature from middle of September up to middle of October, leaf color changes and sheding of different poplar clones starts. Furtheremore time difference of the appearance of living phenomenas and period of any phenomenas in different poplar clones was shorter in 1998 compared to 1997. Investigated poplar clones were groupped based on living activities periods. These clones such as P. e. arges grandis and P. e. marilandica with short growth periods are suitable for cold regions and clones such as P. d. 69/55 and P. e. triplo with longer growth periods are suitable for planting in the warmer regions of our country

Utricularia (Lentibulariaceae) of Iran

Volume: 37Start Page: 4End Page: 1