ECOPERSIA
Year:2024 | Volume:12 | Issue:3|Papers Count:7

Aims: The present study aimed to investigate beta and alpha diversities in vegetation types and examine the relationship between the distribution of plant species and environmental factors in the rangelands of southern Golestan Province, Iran. Materials & Methods: This study was conducted in four vegetation types, namely Artemisia aucheri, Festuca ovina - Astragalus gossypinus, Bromus tomentellus, and Bromus tomentellus - Festuca ovina. The vegetation was sampled using a systematic random sampling approach. Thirty plots measuring one m2 were placed in each plant type along three 50-meter transects to measure the vegetation. In total, 120 plots were placed across the different plant types. Soil samples were collected from a depth of 0-30 cm. The soil depth was selected based on the mountainous terrain and the rooting depth of the plants. The Past software calculated plant species diversity and similarity indices between vegetation types and beta and alpha diversities. The Tukey test was used to compare the diversity indices of the plant functional groups. Findings: The highest alpha diversity among annual plants was observed in the F. ovina-A. gossypinus type with a Shannon-Wiener index of 0.927 and a Simpson index of 0.554. At the same time, the most remarkable alpha diversity of shrub plants was associated with the same type with a Shannon-Wiener index of 1.316 and a Simpson index of 0.711. Across all four studied types, the highest richness of annual and perennial plants was observed in the A. aucheri type, with a Margalef index of 8.192 and a Menhinick index of 5.774. In contrast, the greatest richness of shrub species was observed in the F. ovina-A. gossypinus type, with a Margalef index of 3.734 and a Menhinick index of 2.677. In addition, beta diversity was calculated using the similarity index for vegetation types. The results indicated a Whittaker similarity index (beta diversity) of 0.3, 0.4, and 0.5 for annual, shrub, and perennial plants, respectively. Canonical Analysis (CA) was performed using the Canoco 4.5 software to examine the effect of environmental factors on plant species distribution. The analysis revealed that soil texture, N, organic carbon, pH, EC, and aspect were the most significant factors affecting the distribution of plant species.  Conclusion: This research provides valuable information about rangeland plant species for primary livestock grazing and soil protection in the studied vegetation types for better land management.

Aims:  Studying flood peak discharge trends is crucial to disaster risk reduction in developing countries like Iran. This study aims to analyze the instantaneous peak discharge trend in 301 hydrometric gauge stations using Mann Kendal (MK (and Sen’s Slope estimator tests over Iran. Material & Methods: Data on all existing hydrometric gauge stations in Iran were downloaded from Iran Water Resources Management Company. The hydrometric gauge stations with at least 20 years of data were selected, and the stations that were then affected by the dams were removed. Trend analyses of instantaneous peak discharge were conducted using MK and Sen’s slope estimator tests. Findings: The results showed that out of 301 hydrometric stations, 259 stations have no trend, only three stations have a decreasing trend, and 39 stations have an increasing trend. This trend is more evident in southwestern Iran, where the increase in agriculture, human activity, and climate change is more evident. In the watershed of the eastern border, only one station has a decreasing trend; in the central plateau, four stations have a decreasing trend, and the rest have no trend.  Conclusion: Due to the importance of peak discharge in flood damage, this research can help managers and decision-makers in integrated watershed management. For example, in flood control projects, as well as designing the dimensions of structures such as retard dams, levees, the height of flood control walls, and bridges.

Aims: The natural dependence between the habitats of certain plants and animals can be a factor in ecosystem stability. Canopies of Ligustrum vulgare on the edge of Mohammad Shahr’s (Karaj) gardens in Iran are introduced as a new skink record habitat called Scincella lateralis.  Material & Methods: Direct observations of behavior in habitat and glass container, checking climatic records, and studying the morphological and ecological characteristics of the newly found species. Findings: Ligustrum vulgare provides a suitable and safe canopy for the movement of S. Lateralis due to climate change. S. lateralis lizards are omnivorous and feed on live insect larvae and small insects; the population of insects that were pests has been significantly reduced. It seems that changes in the transitional climate zone from cold and semi-arid to semi-cold and humid have created landscape fragmentation, which can be one of the reasons for the emergence of this species. The body length of the new adult S. lateralis is about 6.5 cm, which is shorter than the reported specimens. It crawls like a snake and behaves like a dinosaur.  Conclusion: The overlap of the L. vulgare vegetation map with the geographic distribution of S. lateralis in America and the repetition of this cooperation in Iran show that this type of lizard can be a valuable indicator for monitoring ecosystem changes. In addition, it is possible to take advantage of the coexistence of these two in the design and management of ecosystems.

Aims: Understanding the structural dynamics of unmanaged oak coppices is crucial, as many of the world’s forests remain unmanaged. While previous studies have focused on coppice dynamics in mesic woodlands, there needs to be a more significant gap in understanding these processes in semi-arid regions. The study aims to examine the structural modifications, successional trajectories, and floristic diversity within semi-arid oak coppices in the Zagros Mountains, utilizing a comprehensive dataset obtained from an extensive land survey. Materials & Methods: The study was conducted in a 175 km strip of Zagros Mountain forests dominated by Quercus brant ii. Ninety-four even-aged stands from 14 forests were selected. Structural attributes were evaluated, including tree density, basal area, canopy cover, and floristic diversity measures. A list of vascular flora was documented for each successional stage using the Raunkiær plant life-form classification. Data analysis involved polar ordination, clustering, and multivariate techniques.  Findings: Density, Holdridge complexity index, basal area, and cover were identified as the most influential variables. Two main trajectories, progressive and retrogressive, were identified, with eight successional stages. Significant differences in structural variables were observed across trajectories, with floristic diversity peaking in the middle stages. The later stages of the progressive trajectory showed a significant increase in the relative cover and basal area of Fraxinus rotundifolia. The study demonstrates the existence of a progressive successional trajectory in unmanaged coppice forests influenced by disturbances. Stand age, mean diameter of sprout clumps, and flora diversity do not solely determine the successional stages within this trajectory. Conclusion: While transforming Zagros Mountain oak coppice into high forests is unlikely, there is potential for redirecting succession toward more resilient and diverse ecosystems. We recommend management interventions beyond protection, promoting uneven-aged stands, increasing density and cover, and encouraging species like Fraxinus. These strategies can enhance ecological integrity and foster sustainable woodland ecosystems in the Zagros region.

Aims: This study aims to economic valuation and assess multiple threats to water and soil resources of the Karkheh National Park and Karkheh Protected Area, southwest of Iran. Methods: Modeling water budget, runoff, soil erosion, and water pollution potential, was performed using the WaterWorld Policy Support System (WWPSS), process-based hydrological model that utilizes remotely sensed and globally available. Eeconomics value has been calculated using the Substitute Cost Method, for 2021. Findings: The result showed that the southern area of the Karkheh River basin experienced the minimum precipitation, which has led to a decrease in vegetation and an increase in runoff generation in the southern areas. The total runoff generated in the river basin is based on the upstream-downstream relationships from the north to the south was estimated at 81000648 m3.yr-1. The soil erosion rate spiked in the southern area with the vegetation decline and the intensification of runoff could be result in water pollution. Economic valuation represents the real value of water generation in the whole Karkheh National Park and Protected Area was US$ 0.104 million, estimated US$ 6.63 per hectare. In addition, the soil conservation economic value in the entire Karkheh National Park and Protected Area was US$ 9.3 million and US$ 912.2, per hectare. Conclusion: This information provides valuable awareness into the economic value of natural resources and can help environmental assessors activities related to conservation planning. It assists as a useful tool for emphasizing the economic implications of ecosystem degradation and can help for sustainable management.

Abstract: Aims: The Meymeh River is fed by several tributaries, leading to a gradual decrease in its quality. Considering the construction of the Meymeh reservoir for agricultural use, it is necessary to monitor the spatial and temporal changes in water quality and to identify areas where river quality changes. Methods: Our method was based on the analysis of 420 samples over 12 months (2016–2017) in three seasons (low, moderate, and high flow periods) from 35 measuring stations using Spearman's correlation, multivariate statistical analysis, agglomerative hierarchical clustering, and GIS. Findings: The results showed that crossing the saline evaporite layers (especially the Gachsaran Formation) causes a gradual decrease in water quality from upstream to downstream. So, EC reaches from 400 to more than 3500 µm. cm-1 at the confluence of Varazan and Kharvazan tributaries. Besides, the sulfur spring with an average EC of 21590 µm. cm-1 increases EC 3.5 times. Siyoul tributary penetrates under the ground after passing through two saline zones and reappears at a distance of 150 to 200 m with an EC of 187800 µm. cm-1. It was also found that about 50% of the salinity of the Meymeh River is caused by the influence of the Ghadah Sulfur Spring and the Siyoul tributary. Conclusion: This study has highlighted some options for managing the level of salinity in the dam. In most cases, one option on its own may not have the desired effect, and a combination of techniques is likely to bring the best results.

Aims: This study investigates the response of some soil bio-physicochemical properties under different grazing intensities management in a 17-year-old arid rangeland ecosystem of Iran. Material & Methods: The grazing intensity gradient was as follows: (1) without herbivore grazing over a whole year (NG), (2) grazing by sheep and goats done communally from November to May (RG), and (3) continuous and heavy grazing over a whole year (HG). The soil samples were collected from the upper 20 cm in November and May.  Findings: The significantly higher bulk density values (P<0.05) were measured with increasing grazing intensities, i.e., 1.65, 1.82, and 1.96 g.cm-3 in NG, RG, and HG, respectively. The management system affected significantly (P<0.05) organic carbon (OC), total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), as well as enzyme activity of acid- and alkaline phosphatase (ACP, ALP) and urease. Similarly, the time of sampling affected significantly (P<0.05) OC, P, C, ACP, ALP, and urease activity in the soil. The soil OC ranged from 0.46 to 2.78 %, K ranged from 51.81 to 92.06 ppm, TN and P showed significantly (P<0.05) higher HG and RG values than NG. The soil pH ranged from 7.89 to 8.32, and EC (electric conductivity) ranged from 0.47 to 0.93 dS.m-1, which was significantly affected neither by the grazing management system nor by sampling time. The TN showed a high positive correlation with ALP (r = 0.89), urease (r = 0.72), and dehydrogenase (r = 0.76). The OC, P, ACP, and ALP responded more sensitively to grazing management systems. Conclusion: The presence of animals in our study site positively affected soil fertility. However, similar studies are required to complete our knowledge under different climatic conditions, vegetation-grazer types, and grazing duration.