Spatial and temporal analysis of land cover and landscape structure change in Zagros Forests

The Zagros oak forests in Western Iran are critically important to the sustainability of the region. These forests have undergone dramatic declines in recent decades. We evaluated the utility of the non-parametric Random Forest classification algorithm for land cover classification of Zagros landscapes, and selected the best spatial and spectral predictive variables. The algorithm resulted in high overall classification accuracies (\u3e85%) and also equivalent classification accuracies for the datasets from the three different sensors. We evaluated the associations between trends in forest area and structure with trends in socioeconomic and climatic conditions, to identify the most likely driving forces creating deforestation and landscape structure change. We used available socioeconomic (urban and rural population, and rural income), and climatic (mean annual rainfall and mean annual temperature) data for two provinces in northern Zagros. The most correlated driving force of forest area loss was urban population, and climatic variables to a lesser extent. Landscape structure changes were more closely associated with rural population. We examined the effects of scale changes on the results from spatial pattern analysis. We assessed the impacts of eight years of protection in a protected area in northern Zagros at two different scales (both grain and extent). The effects of protection on the amount and structure of forests was scale dependent. We evaluated the nature and magnitude of changes in forest area and structure over the entire Zagros region from 1972 to 2009. We divided the Zagros region in 167 Landscape Units and developed two measures— Deforestation Sensitivity (DS) and Connectivity Sensitivity (CS) — for each landscape unit as the percent of the time steps that forest area and ECA experienced a decrease of greater than 10% in either measure. A considerable loss in forest area and connectivity was detected, but no sudden (nonlinear) changes were detected at the spatial and temporal scale of the study. Connectivity loss occurred more rapidly than forest loss due to the loss of connecting patches. More connectivity was lost in southern Zagros due to climatic differences and different forms of traditional land use

Analyzing effective protection for roe deer (Capreolus capreolus) habitat in Iranian Zagros forests at two scales

Background/Question/Methods Bozin and Marakhil forest was designated protected area in 1999 to restore habitat for roe deer (Capreolus capreolus). It is located in Kermanshah province, Iran, and covers 23724 ha of semi-arid Zagros forests. Research in Europe has identified the importance of landscape structural characteristics, such as patch edge and contiguity, as important determinants of home-range and population sizes of roe deer. We analyzed landscape changes from 2001 to 2009 inside and outside of this protected area at two scales (Landsat: 30m grain and ~ 6750000 ha extent; and IKONOS/GeoEye: 1m grain and ~16500ha extent). Radiometric corrections and orthorectification were followed by the classification of images to five cover classes using Random Forest algorithm. All available structure metrics were calculated at patch and class level for forests using a 8 cell neighborhood rule. A principal component analysis was applied on the structure metrics at patch level in order to avoid redundancy and select orthogonal metrics for comparison. The selected metrics were used to compare forest structure at general Zagros forests as well as protected and unprotected areas at the two time steps. The areas of the unprotected area located in Iraq were clipped out in order to eliminate the socioeconomic effects and the differences in national management policies. Results/Conclusions At the Landsat scale the selected orthogonal metrics with the highest loadings on the first two principal components (explaining 88% and 86% of the variation in 2001 and 2009, respectively) were patch area, shape index, and contiguity index. Class level metrics showed a 14.5 % forest loss and a 5.4 unit decrease in edge density for the general Zagros forest from 2001 to 2009. While there was no significant change in amount of forest in the protected area or the immediate area, there was an increase in patch connectivity inside of the protected area (p \u3c .01). However, no significance difference was found for the value of the selected patch level metrics for general Zagros structure at the two time steps. These analyses at the first scale suggest that either 1) the park is functioning to protect important roe deer habitat characteristics (and the protection has increased the spatial connectedness of habitats), or 2) the increased habitat connectedness is due to the higher initial forest cover in the protected area. This requires analyses at the fine scale

Spatial and temporal deforestation dynamics of Zagros forests (Iran) from 1972 to 2009

The emerging interest in sudden losses in vegetation and forest cover in semi-arid areas has led to a new understanding of the patterns and processes of deforestation. The Zagros oak forests in western Iran have undergone dramatic changes in cover and structure in recent decades, with negative consequences for the communities that depend upon them. This study had three objectives: (1) evaluate the nature and magnitude of these changes from 1972 to 2009 through trends in forest area and connectivity; (2) evaluate the changes in forest area and landscape connectivity across a climatic gradient; and (3) evaluate the effect of topographical variations. Landsat MSS, TM, and ETM+ images for the region were preprocessed and corrected prior to classification of 167 landscape units (LU; 400 km2 each). We developed two measures – deforestation sensitivity (DS) and connectivity sensitivity (CS) – for each LU. A considerable but relatively linear loss in forest area and connectivity was detected. Connectivity loss occurred more rapidly than forest loss due to the loss of connecting patches. More connectivity was lost in southern Zagros due to climatic differences and different forms of traditional land use. Steep slopes and high elevations experienced more forest loss and connectivity. In northern Zagros the coppice form of forest management should be supported as a method that maintains connectivity. In southern Zagros, restoration projects should focus on regeneration in forest gaps to restore connectivity between isolated forest fragments. The study provides large scale information for restoration projects across a spatial climatic gradient

Grass trumps trees with fire

Ecologists have long assumed that forests, savannas, and grasslands change gradually over space and time, with tree cover responding linearly to gradients in precipitation, aridity, fire disturbance, and grazing pressure. However, a growing body of evidence suggests that these biomes are self-reinforcing and that transitions between them can be nonlinear, governed by feedbacks at local and regional scales (1–3). Two reports in this issue, by Staver et al. on page 230 (4) and by Hirota et al. on page 232 (5), find evidence for these feedbacks and transitions at the global scale. These results suggest that global climate change will be substantially influenced by nonlinear behaviors and feedbacks between biophysical and human systems

Restoring oak regeneration after overgrazing and fire in Zagros forests

Zagros oak forests have a long history of use by local communities. Palynological research provides evidence of stock breeding, grazing, and agriculture at least since the beginning of the fifth millennium cal B.P. (Djamali and others 2009, Sumner 1990, Wright and others 1967). The traditional sustainable management was maintained by a homeorhetic regulation in pre-technological land use (Naveh 1988). This regulation was acquired by a balance between the anthropogenic utilization of the forests for livelihood necessities and stabilizing feedbacks from a lack of food, water, and social components, generating a resource protection mechanism. Resource utilization activities such as coppicing and cultivation were practiced by rotations (Ghazanfari and others 2004). Landscapes maintained a patchwork formed by the combined effects and interaction of fire, grazing, and coppicing

Effects of protection on amount and structure of forest cover at two scales in Bozin and Marakhil protected area, Iran

Official protection can play a major role in the conservation of biodiversity and sustainable management of endangered species habitat. Bozin and Marakhil Forest in Kermanshah province of Iran covers 23,724 ha of semi-arid Zagros forests. It was designated as a protected habitat area for Eurasian roe deer (Capreolus capreolus) in 1999, a species that thrives on forest edge habitat. Using remote sensing data from 2001 and 2009, we evaluated the effects of this protected designation on forest area and structure at two spatial scales. We processed and classified Landsat images for the two dates covering the protected area and the adjacent unprotected areas for the broad scale analysis. We classified IKONOS and GeoEye images of the two dates covering a part of protected and unprotected areas for fine scale analysis. Protection had a scale dependent influence on habitat availability and structure. A small difference due to protection at the fine scale was increased fractal dimension of forest patches as a measure of habitat complexity, likely due to reduced human impact. The official protection maintained habitat availability, contiguity, and complexity at the broad scale, probably at the expense of increasing human pressure on the surrounding unprotected areas. Given this scale dependency of protection effects on habitat amount and structure, the actual effects of protection would depend on the practical home range size and scale at which species use the habitats

Deforestation and landscape structure changes related to socioeconomic dynamics and climate change in Zagros forests

The Zagros region of western Iran has been affected by the recent changes both in amount and in structure of forest cover. We evaluated the influence of several driving forces on forest cover and structure, including socioeconomic (urban and rural population and rural income) and climatic (mean annual rainfall and mean annual temperature) variables. We acquired all time series Landsat images of a study site from 1972 to 2009. The images were classified to produce a land cover map of each year. We calculated landscape and patch metrics and identified independent sets of metrics to describe forest change. The most influential driving force for forest loss was urban population and climatic variables to some extent. These challenges should be addressed at broader scales than those associated with the livelihoods and traditional management of local communities. Rural population had a significant association with landscape structure which should be considered in designing restoration projects

Classification of Landsat images based on spectral and topographic variables for land-cover change detection in Zagros forests

Detection of land-cover changes through time can be complicated because of sensor-specific differences in spatial and spectral resolutions; classified land-cover changes can be due to either real changes on the ground or a switch in sensors used to collect data. This study focused on two objectives: (1) selecting the best predictor variables for the classification of semi-arid Zagros forests given the characteristics of the study area and available data sets and (2) evaluating the application of the random forest (RF) algorithm as a unified technique for the classification of data sets acquired from different sensors. Three images of the same study area were acquired from the Landsat-5 Thematic Mapper (TM) sensor in 2009, the Landsat-7 Enhanced Thematic Mapper (ETM+) sensor with Scan Line Corrector (SLC) in 1999 and the Landsat-2 Multispectral Scanner (MSS) sensor in 1975. Following image preprocessing, the RF algorithm was applied for variable selection and classification. A test of equivalence was used to compare the overall accuracy of the classified maps from the three sensors. Slope, normalized difference vegetation index (NDVI) and elevation were determined to be the most important predictor variables for all three images. High overall classification accuracies were achieved for all three images (97.90% for MSS, 95.43% for TM and 95.29% for ETM). The ETM- and TM-derived maps had equivalent overall accuracy and even significantly higher overall accuracy was obtained for the MSS-derived map. The post-classification comparison showed an increase in agriculture and a decrease in forest cover. The selected predictor variables were consistent with ecological reality and showed more details on the changes of the land-cover classes across biophysical variables of the study area through time

Water flows toward power: Socioecological degradation of Lake Urmia, Iran

Water is an invaluable resource, and equitable access to it is a fundamental human right. Disenfranchised groups often lose access to water resources because their interests are not well represented by decision makers. Excluding these groups from resource management policy often results in myopic decisions that contribute to further ecosystem damage. We describe the ecological degradation of Lake Urmia in Iran, which has recently experienced increased salinity and declining water quantity. The lake is a UNESCO Biosphere Reserve and Ramsar site, and supports unique biodiversity in the region. The lake\u27s decline is driven by the destruction of Zagros forests and the government\u27s water policies, which diverted water to more politically connected agricultural land users, increasing social inequity and prompting more deforestation. The most straightforward restoration solution is to discontinue the diversions and allow critical inflows to recharge Lake Urmia, preserving the lake and wetlands for migratory birds, tourists, and local communities

Study of different restoration and regeneration techniques in northern Zagros (Case study: Armardeh oak forest, Baneh)

With covering an area of 14 ha, the investigated site is located in Armardeh Oak forests of Baneh city, Kurdistan province. The main problem of these forests is the lack of regeneration. In this research four different techniques of restoration operations, all of them in the shape of a participatory management approach were tested as randomized complete Design (RCD) with 5 treatment and 30 replications. The techniques are as follows: fencing outside the crown coverage, fencing beneath the crown coverage, fencing along with direct seeding and fencing plus seeding via Jiffy pellet technique. For the quantitative and qualitative measurements, thirty permanent macro plots each 1000 m2, were laid out in the study area randomly. Five microplots, each 1m2, were laid out within the macro plots for the restoration techniques. Inputs of the test were the number of primer seeds and outputs were number of seedlings and their heights. The results showed that only 2% of shed seeds have been converted to seedlings by late spring. Using fencing, even out of crown cover, caused increasing in natural regeneration up to one seedling per m2, Therefore, it seems that the main limiting factor of regeneration is livestock grazing. If fencing exerts beneath crown cover, natural regeneration will increase up to 3.9 seedlings per m2. Applying artificial methods increased regeneration significantly. Conservation with seeding via Jiffy pellet technique showed to be  the best technical method either from number of seedlings or their heights point of view