The effect of different degrees of burial in windy sand on some physiological and vegetative characteristics of Qara Dagh and Rames species.

Abstract

In this research, the effect of different degrees of burial in windy sand on some physiological and vegetative characteristics of Qara Dagh and Rames species was measured. One-year-old saplings of Qarhadagh and Rames species were obtained from the nursery of the General Department of Natural Resources of Yazd province and subjected to five control treatments, burial with sandblasting up to one-third of the plant height (from the collar), burial up to half of the plant height, burial up to three-fourths of the plant height, and complete burial. After six months of irrigation and care, some physiological and vegetative traits of these plants were measured. The results of Garhadagh species showed that the proline and auxin content of leaves increased significantly in all three burial treatments compared to the control and complete burial. The highest amount of stem sugar was observed in the complete treatment and the highest amount of root sugar was observed in the burial treatment of 1.3. The amount of sodium in the stem in all burial treatments was significantly higher than the control, this increase was about five times. The highest amount of stem phosphorus was obtained in the 1.2 treatment and the lowest in complete burial, so that its amount in the 1.2 burial treatment was about 6 times that of complete burial. The amount of root phosphorus in the burial treatment was 1.2 times more than 7.5 times its amount in the complete burial treatment. The number of rhizomes was significantly higher than the control in all burial treatments. The highest number was obtained in the burial treatment of 1.2. Burial treatments had a negative effect on the number of branches. The length of the stem in two burial treatments was 1.2 and 3.4 more than twice that in the control. The weight of the stem in the burial treatment was 1.3 to more than 1.5 times its value in the control. Root weight in all three burial treatments showed a significant increase compared to the control and complete burial. Also, the results of Rames species showed that the highest amount of leaf proline was measured in the burial treatment of 1.3 and the lowest amount of leaf proline was measured in the burial treatment of 3.4. The amount of root proline in each burial treatment was significantly higher than the control. The amount of auxin in the three burial treatments increased significantly compared to the control. The highest amount of stem sugar was observed in the 1.3 treatment and the highest amount of root sugar was observed in the control. The amount of sodium in the stem and root in burial treatments was significantly increased by 1.3 and 1.2 compared to the control and 3.4. The amount of potassium in the stem and root in the burial treatments of 1.3 and 1.2 was significantly higher than that of the control. The amount of phosphorus in the roots in the burial treatment was 1.3 times more than that in the control. The length of the stem in Timardefen was 3.4 twice that in the control. The highest amount of stem weight, stem dry weight and root weight was observed in the burial treatment of 1.3.

Keywords: Qara Dagh, Rames, sand wind, physiological, vegetative

Introduction

The trend of land expansion Desertification in all parts of the world, including our country, is one of the problems that its control is considered as a global concern. The phenomenon of erosion (both water and wind) is considered as one of the main processes of land destruction in the regions of the world, including Iran. With the increase in population and efforts to meet human needs on the one hand, and human access to natural resources along with unprincipled managements, during the 20th century, scientific and practical research related to this phenomenon has attracted the attention of researchers. The phenomenon of wind erosion works in arid and semi-arid climates, and considering that more than two-thirds of Iran's area is located in this area, therefore, in addition to water erosion, wind erosion is an effective factor in destroying and causing damage in these areas. According to the statistics provided by the Sand Stabilization and Desertification Office of the Forestry Organization, pastures and watersheds in about 20 million hectares of the country's lands are under the effect of wind erosion. Of this amount, about 7 million hectares are in the harvesting area, 6 million hectares are in the transport area, which includes sedimentation at the base of plant bushes, Nebka and Rabdo, wide sand areas with a maximum height of 1-2.5 meters and scattered sand areas with a maximum height of one meter, 4392000 hectares of active citadel and 2 million hectares of old stabilized sand dunes.Despite the very extensive and significant measures taken by the natural resources operators to stabilize and control more than 2 million hectares of sand dunes and areas in the country, according to the latest studies conducted by the Office of Desert Affairs (sand stabilization and de-desertification), there are more than 1 million hectares of active sand dunes in the country, which sometimes threaten economic and biological resources and must be controlled (Technical Office and Sand Stabilization) Desertification 1381). On the other hand, more than 64.5% of the country's area is affected by ultra-arid climatic conditions with less than 250 mm of rainfall (Khalili 1371) and more than 95% of the country's wind-blown sand deposits are also located in this climatic area (Technical Bureau of Sand Stabilization and Desertification 1381). One of the main reasons for severe erosion in Iran is the loss of vegetation. Therefore, due to the severe climatic conditions, especially the lack of rainfall, the establishment of plant species in these areas is very difficult and requires sufficient accuracy and compliance with all aspects in the selection of plant species and the adoption of appropriate strategies for their cultivation and maintenance (Special 1382). Vegetation is like an umbrella that protects the earth, regulates the flow of surface and underground water, and is very important in preserving the soil and preventing erosion. Plant species have diverse habitats and sometimes they are seen on different types of soils, but to stabilize windblown sand, species that tend to settle on sand deposits are selected. Meanwhile, the type and depth of deposits, their mobility, depth of stagnation, air humidity, or any factor that plays a role in the physical and chemical conditions of the planting bed, will be effective in selecting plant species (Khatsasi, 2019). The main elements that make up Nabka include sand, silt, clay and silt, and they are seen in both active and inactive forms (Ahmadi, 2017). Factors affecting the height of Nabka include plant parameters (crown, density, etc.), roughness and slope. In addition to these factors, environmental factors (Bochet et al, 2000) and human activities (Tengberg, 1995) are also involved in the development of Nebka. Nebka formation increases above-ground composition such as height or number of leaves in plants (Zhang and Maun, 1990). Sand deposition and nebka formation create physical changes such as moisture, heat, ventilation (aeration) in the plant microhabitat (Maun, 1998). Burial acts like a filter and selects and removes sensitive species and reduces the relative abundance of less resistant species and increases resistant and sand-dependent species (Maun, 2004). But if the sedimentation continues, even the sand dependent species will be removed and an area devoid of vegetation will be created (Maun, 1998). This threshold is different in different species (Zhang et al, 2002). By maintaining resistant species and removing sensitive species, intra-species and inter-species competition is reduced (Perumal and Maun 2006). The burial of plants causes the photosynthesizing organs to be covered by sediments, which is considered a physical barrier for the upward growth of plants. (P. Dech, 2006 and Maun). Burying in sand may result in the movement of biomass and nutrients from the root side to the upper part of the soil while maintaining photosynthetic capacity (Harris 1987, 1988 and Davy). Also, sediments cause changes in soil pH (according to the acidity of deposited sand). With the increase of sand deposition, nutrients and soil volume expand in the root zone and the amount of moisture may increase (Maun, 1998). Studies show that under a certain threshold of burial level, the growth of all plant species in the coastal zone is stimulated (Maun, 1998; F. Brown, 1997). In seedlings that have the ability to adapt to these conditions, the number of nodes increases and the length of the nodes grows (Zhang et al, 2002).  Burying in windy sand causes abundant formation of ectopic roots for the development of stems of A. gmelinii plants growing in sand dunes (Samsone et al. 2009). In general, plants buried in windy sand show an increase in biomass, photosynthetic efficiency and chlorophyll, which is due to the high energy content in their roots, rhizomes and underground stems, which is why the growth in leaf area, leaf thickness and biomass The root is inhibited (Perumal et al. 2005).

(Gilbert et al. 2008) by examining the total biomass and transfer of leaf resources in support of plant growth in the hill after burial in sand found that physiological changes are of great importance in determining the nature of the response to burial. (Burylo et al. 2009) found that in some species, the resistance to burial in marl sediments is related to the accumulation of plant sugar in the root.

Also (Burylo et al.