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A minimum set of soil indicators for the semi-arid rangeland productivity assessment

100%

Saedi K., Fatehi P., Khaksarian F., Rezaei S. A.

Polish Journal of Ecology

2017

tom 65

nr 1

An approach has been adopted in order to select the most representative and predictive indicators as minimum data set (MDS) for the assessment of rangeland soil quality. Large data sets were employed for the high hill rangeland in the Saral region, Kurdistan province, west of Iran. The correlations between soil properties and plant growth in various landscape units were investigated and interpreted based on statistical analyses. Multivariate statistical techniques were used to determine the minimum set of indicators among chemical and physical variables, as well as soil surface indices of Landscape Function Analyses (LFA) approach that account for at least 70% of the variability in the whole data set of aboveground plant biomass production among land units. The MDS was selected for its ability to predict soil productivity, as site potential of a long-term rangeland exclosure. The efficacy of the chosen MDS was evaluated by performing multivariate regressions of the MDS against each of the plant growth characteristics (P ≤ 0.05). These dependent characteristics included total yield, herbaceous plant production, and utilizable forage. Variations in the plant response variables were best predicted by Nutrient cycling index, Land organization index, and total nitrogen illustrating that plant variables were more sensitive to the chemical rather than the physical properties of the soil.

Maxent modelling for distribution of plant species habitats of rangelands (Iran)

100%

Zare Chahouki M. A., Piri Sahragard H.

Polish Journal of Ecology

2016

tom 64

nr 4

Quantifying the pattern of habitat distribution for range plant species can assist sustainable planning of rangeland use and management. However, data of plant species distribution are often scarce and modeling of habitat distribution using commonly used models is difficult. In this study, the Maximum Entropy Method (MaxEnt) was used to model the distribution of plant habitat to find the effective variables in plant species occurrence in the Poshtkouh rangelands on Yazd province, central Iran. Maps of the environmental variables were generated using GIS and Geostatistics facilities. Accuracy of model output was assessed using area under the curve (AUC) of the receiver operating characteristic and keeping 30 percent of the data. Evaluation of model accuracy by AUC indicated good and acceptable predictive accuracy for all plant species habitats, except Artemisia sieberi which had high frequency. The predictive maps of Artemisia aucheri, Scariola orientalis — Astragalus albispinus, A. sieberi₂ and A. sieberi — Zygophyllum eurypterum had fair agreement with their corresponding observed maps. In addition, the accuracy of S. orientalis — A. sieberi and Tamarix ramosissima predictive maps was low and the estimated conformity rate of prediction and observed maps was poor. In fact, due to differences in the optimal ecological range, level of agreement of predictive and observed maps at each site was different. MaxEnt was substantially excellent to predict distributions of plant species habitat with narrow ecological niches e.g. Rheum ribes — A. sieberi, Seidlitzia rosmarinus and Cornulaca monacantha. It can also perform well with fairly few samples due to employing regularization.

Comparison of different geostatistical methods for soil mapping using remote sensing and environmental variables in Poshtkouh rangelands, Iran

100%

Hosseini S. Z., Kappas M., Budaghabadi M. B., Chahouki M. A. Z., Khojasteh E. R.

Polish Journal of Environmental Studies

2014

tom 23

nr 3

The aims of this study were: 1) to map the different soil parameters using three geostatistical approaches, including; ordinary kriging (OK), cokriging (CK), and regression kriging (RK), 2) to compare the accuracy of maps created by the mentioned methods, and 3) to evaluate the efficiency of using ancillary data such as satellite images, elevation, precipitation, and slope to improve the accuracy of estimations. In the rangelands of the Poushtkouh area of central Iran, 112 soil samples were collected. The maps of different soil parameters were created using the mentioned methods. To assess the accuracy of these maps, cross-validation analyses were conducted. The cross-validation results were assessed by the root mean square error (RMSE) and normal QQ-plot together with sum and average error to suggest the best estimation approach for mapping each soil parameter. The results have shown that, in most cases, taking the ancillary data into account in estimations has increased the accuracy of the created maps. Except for clay, the OK method was suggested as the best estimation method, and the RK and CK were the best recommended estimation methods for the rest of the parameters. The results suggest the application of the framework of this study for similar areas.

Ograniczanie wyników

2 Polish Journal of Ecology

1 Polish Journal of Environmental Studies

1 Budaghabadi M. B.

1 Chahouki M. A. Z.

1 Fatehi P.

1 Hosseini S. Z.

1 Kappas M.

1 Khaksarian F.

1 Khojasteh E. R.

1 Piri Sahragard H.

1 Rezaei S. A.

1 Saedi K.

1 Zare Chahouki M. A.

1 2017

1 2016

1 2014

Wyniki wyszukiwania

A minimum set of soil indicators for the semi-arid rangeland productivity assessment

Maxent modelling for distribution of plant species habitats of rangelands (Iran)

Comparison of different geostatistical methods for soil mapping using remote sensing and environmental variables in Poshtkouh rangelands, Iran