مطالعه فلوریستیکی و خاک‌شناسی محدوده آب‌بندان ملاط شهرستان لنگرود

شناسایی گونه‌های گیاهی هر منطقه بازتابی از عوامل مختلف بوم‌شناختی آن است. آب‌بندان ملاط شهرستان لنگرود یک بوم‌سازگان آبی پایدار در شمال کشور است که نقش مهمی‌ در تامین آب شالیزارها دارد. در این مطالعه، شناسایی ترکیب فلوریستیک، شکل زیستی، پراکنش جغرافیایی گیاهان و خاک‌شناسی محدوده آب‌بندان ملاط شهرستان لنگرود بررسی شد. ابتدا، جمع‌آ‌وری نمونه‌های گیاهی از این آب‌بندان، مناطق پست و جلگه‌ای اطراف و مناطق جنگلی مشرف بر آن انجام گرفت. سپس از افق سطحی رویشگاه‌ها نمونه خاک برداشت و برخی خصوصیات فیزیکی و شیمیایی آن‌ها تعیین شد. براساس نتایج حاصل، از مجموع 250 نمونه گیاهی جمع‌آوری شده، 60 خانواده، 127 جنس و  146 گونه گیاهی شناسایی شد. خانواده‌های گیاهی poaceae با 22 جنس و asteraceae با 11 جنس پرجمعیت‌ترین خانواده گیاهی از نظر جنس را تشکیل دادند. همچنین poaceae و fabaceae با 24 و 15 گونه دارای بیشترین غنای گونه‌ای بودند. بیشترین درصد گونه‌های گیاهی منطقه دارای شکل زیستی غالب تروفیت (7/29%) و همی‌کریپتوفیت (2/26%) و بیشترین فراوانی پراکنش جغرافیایی، عناصر رویشی چندناحیه‌ای (5/31%) بودند. بررسی خصوصیات خاک رویشگاه این گیاهان، نشان از یکنواختی بافت خاک (کلاس متوسط تا سبک) و نبود شوری با هدایت الکتریکی کمتر از یک دسی‌زیمنس برمتر (ds/m) بود. دامنه ph خاک از خنثی (78/6) تا به شدت اسیدی (03/4)، دامنه کربن آلی در کلاس متوسط تا بهینه و میزان n-p-k در کلاس متوسط تا غنی قرار داشتند. مطالعه فلوریستیکی منطقه ضمن افزایش شناخت آن، زمینه لازم را برای مطالعات جامع‌تر و اعمال مدیریت در این منطقه توریستی فراهم می‌کند.

floristic and soil study of the malat water pond in langarud city

identification of plant species in each region is a reflection of its various ecological factors. malat storage pool of langarud city is a stable water ecosystem in the north of the country, which plays an important role in supplying water to paddy fields. in this study, floristic composition, life form, geographical distribution of plants and soil characteristics of malat storage pool area of langarud city were investigated. first, plant samples were collected from this storage pool, surrounding lowlands and plains and forest areas overlooking it. then, soil samples were taken from the surface horizon of habitats and some of their physical and chemical properties were determined. based on the results, a total of 250 plant samples were collected, which belonged to 60 families, 127 genera and 146 species. the plant families poaceae with 22 genera and asteraceae with 11 genera formed the most populous plant family in terms of genera. also, poaceae and fabaceae had the highest species richness with 24 and 15 species. the highest percentage of plant species in the region had the predominant life form of therophyte (29.7%) and hemicryptophyte (26.2%) and the highest frequency of chorological type was pluriregional vegetative elements (31.5%). examining the properties of the soil showed the uniformity of the soil texture (medium to light class) and the absence of salinity with electrical conductivity less than 1 (ds/m). the range of soil ph ranged from neutral (6.78) to strongly acidic (4.03), the range of organic carbon was in the medium to optimal class, and the amount of n-p-k was in the medium to rich class. the present floristic study can provide the basis for more comprehensive studies and management practices in this touristic area.  introductionfloristic studies are the base of ecological investigations, prediction of the future situation and management application in each region (azarnivand and zare chahouki, 2010). because of the diverse climatic conditions of iran, different ecosystems and as a result a very rich and unique biodiversity is observed in the country. so, 65 families, 359 genera and 8112 species of vascular plants occur in iran, of which 2597 are endemic (approximately 32%) (noroozi et al., 2019). floristic research in iran has a long history due to its species richness (jafari and zarifian, 2016). also, in the north of iran, floristic studies have been conducted in diverse habitats, including aquatic ecosystems (asri and moradi, 2004; ghahreman et al., 2004; tavakoli et al., 2013; yari et al., 2018; moradi et al., 2020; hosseinalizadeh ahangar and jafari, 2021). soil, as one of the elements of the ecosystem, has a major role in the change and diversity of plant species, and on the other hand, the plant type also has a significant role in the change and transformation of the physical, chemical and biological characteristics of soils. malat water pond located in the south of langarud city as small reservoir for regulating and storing water play an important role in supplying and compensating the water shortage of paddy fields downstream. the aims of the current study are collection, identification and introduction of plant species in order to provide a floristic list of the area of water ponds on the southern edge of langarud city. materials and methodsthe collection of samples was conducted during early spring to late autumn 2022. then drying and preparing the samples was done. the samples were identified using some floristic references (rechinger, 1963-2015; davis, 1965-1988; bor, 1968; ghahreman, 1978-2022; assadi, 1993-2022; mozaffarian, 2018). the chorological types (zohary, 1973; takhtajan, 1986) and life forms (raunkiaer, 1934) of taxa were determined. for soil assessment, four height ranges soil profile were collected and their a horizon was investigated for some physical and chemical properties such as soil texture, electrical conductivity of saturated extract, reaction of saturated soil extract, soil organic carbon, total soil nitrogen, soil absorbable phosphorus and potassium. results and discussionaccording to results, 147 plant taxa were identified belonging to 60 families, 127 genera and 146 species. poaceae with 22 genera and 24 species was the biggest family of the region. this result is in accordance with some studies on the similar regions in iran (e.g., hosseinalizadeh ahangar and jafari, 2021). also, rumex l., trifolium l. and rubus l. (each with three species) were the biggest genera of the study area. regarding life form, therophytes (29.7%) were the dominant group of the area. this observation can be the reflection of some conditions of the region such as the dominance of drought in some times of the year (habibi et al., 2013), human disturbances through some actions such as overgrazing and tourism. investigating the chorological types of the species, revealed that pluriregional (pl, 30.9%) elements were the biggest group in the area. this could be reflection of the favorable environmental and biological conditions for the growth and expansion of different plants with different biological requirements. examining the soil characteristics of the studied area showed that the soil texture, salinity and lime content were uniform in the altitude ranges from -20 to 325 meters above sea level. the soil texture in medium to light class, electrical conductivity was less than 1 ds/m. conclusionnorth of iran, due to having suitable temperature, regular rainfall and proximity to the sea, has provided suitable conditions for the diversity of plant species. in the studied area, the presence of species of the poaceae and fabaceae families is very important for their fodder value and soil protection against water and wind erosion, while the presence of some identified species of the asteraceae family in the area indicates the destruction of vegetation, livestock grazing, and human manipulations. many of the identified plants are very important for the people of the region in terms of medicinal and edible properties.