scholarly journals Minimum forest cover required for sustainable water flow regulation of a watershed: a case study in Jambi Province, Indonesia

2018 ◽  
Vol 22 (1) ◽  
pp. 581-594 ◽  
Author(s):  
Suria Tarigan ◽  
Kerstin Wiegand ◽  
Bejo Slamet ◽  
Keyword(s):  
Ecosystem Services ◽  
Water Flow ◽  
Oil Palm ◽  
Forest Cover ◽  
Assessment Tool ◽  
Elaeis Guineensis ◽  
Swat Model ◽  
Rapid Expansion ◽  
Control Surface ◽  
Direct Runoff

Abstract. In many tropical regions, the rapid expansion of monoculture plantations has led to a sharp decline in forest cover, potentially degrading the ability of watersheds to regulate water flow. Therefore, regional planners need to determine the minimum proportion of forest cover that is required to support adequate ecosystem services in these watersheds. However, to date, there has been little research on this issue, particularly in tropical areas where monoculture plantations are expanding at an alarming rate. Therefore, in this study, we investigated the influence of forest cover and oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations on the partitioning of rainfall into direct runoff and subsurface flow in a humid, tropical watershed in Jambi Province, Indonesia. To do this, we simulated streamflow with a calibrated Soil and Water Assessment Tool (SWAT) model and observed several watersheds to derive the direct runoff coefficient (C) and baseflow index (BFI). The model had a strong performance, with Nash–Sutcliffe efficiency values of 0.80–0.88 (calibration) and 0.80–0.85 (validation) and percent bias values of −2.9–1.2 (calibration) and 7.0–11.9 (validation). We found that the percentage of forest cover in a watershed was significantly negatively correlated with C and significantly positively correlated with BFI, whereas the rubber and oil palm plantation cover showed the opposite pattern. Our findings also suggested that at least 30 % of the forest cover was required in the study area for sustainable ecosystem services. This study provides new adjusted crop parameter values for monoculture plantations, particularly those that control surface runoff and baseflow processes, and it also describes the quantitative association between forest cover and flow indicators in a watershed, which will help regional planners in determining the minimum proportion of forest and the maximum proportion of plantation to ensure that a watershed can provide adequate ecosystem services.

scholarly journals Minimum forest cover for sustainable water flow regulation in a watershed under rapid expansion of oil palm and rubber plantations

2017 ◽  
Author(s):  
Suria Tarigan ◽  
Kerstin Wiegand ◽  
Keyword(s):  
Land Use ◽  
Water Flow ◽  
Oil Palm ◽  
Forest Cover ◽  
Flow Regulation ◽  
Rapid Expansion ◽  
Forest Land ◽  
Direct Runoff ◽  
Regulation Function ◽  
Water Flow Regulation

Abstract. In many tropical regions, rapid expansion of monoculture plantations has led to a sharp decline of forest cover, which potentially degraded the water flow regulation function of watersheds. The flow regulation function of a watershed is defined as the ability of the watershed to store the rain water, therefore reducing the direct runoff and sustaining the baseflow during dry season. In the tropical region where rainfall is highly seasonal, water flow regulation is an important ecosystem function of a watershed. It determines the proportion of direct runoff of the rainfall and the proportion of the baseflow in the streamflow. The higher the proportion of the direct runoff of the rainfall the higher the probability that water resources problems occur such as flooding in the wet season and drought in the dry season. Therefore proper water flow regulation function of a watershed is a key factor for water resources management. It is generally known that forest land use improves the water flow regulation function of a watershed. The contribution of forest land use on water flow regulation function of a watershed depends primarily on its proportion in the entire watershed. In a watershed where expansion of agricultural plantations occurs rapidly, the spatial planner needs to know the minimum proportion of forest cover required to maintain proper water flow regulation function of a watershed. Research dealing with this issue is still rare, especially in the tropical area where oil palm expansion occurs at alarming rate. We employed the SWAT hydrological model to calculate two indicators of water regulation function of a watershed: the proportion of the direct runoff to the rainfall (C) and the proportion of the baseflow in the total streamflow (BFI). Using regression analysis, we show a strong correlation between indicators of water flow regulation (C and BFI values) with the proportion of forest cover and agricultural plantation cover in a watershed. To achieve the required C value of less than 0.35, the proportion of forest cover in the entire watershed should be greater than 30 % and the proportion of plantation cover should be less than 40 %. The results of this study are very useful as a guide for spatial planners to determine the minimum proportion of forest conservation area to maintain a sustainable ecosystem service of water flow regulation in a watershed.

scholarly journals Estimation of sediment production in oil palm expansion areas in the Amazon

2018 ◽  
Vol 22 (5) ◽  
pp. 344-348 ◽  
Author(s):  
Antonio K. L. Silva ◽  
Adriano M. L. de Sousa ◽  
Joyse T. S. dos Santos ◽  
João M. Villela ◽  
Lucieta G. Martorano ◽  
...  
Keyword(s):  
Oil Palm ◽  
Assessment Tool ◽  
Elaeis Guineensis ◽  
Swat Model ◽  
National Level ◽  
Sediment Production ◽  
Secondary Vegetation ◽  
Using Data ◽  
Water Assessment ◽  
A Current

ABSTRACT Currently, an activity that has become strategic at a national level is the cultivation of oil palm (Elaeis guineensis) in the northeast region of the Pará State, in eastern Brazilian Amazon. However, the impacts of this crop expansion on the hydro-sedimentological cycle are still unknown. Therefore, this study estimated the impacts of oil palm crop expansion on sediment production in a sub-basin under consolidated use of this crop. The Soil and Water Assessment Tool (SWAT) model was applied in the Mariquita sub-basin, calibrated by the flow regionalization technique, using data measured in the field with a current meter. Simulation results indicated an increase in sediment production between the years 2008 and 2013, which can be attributed to the large reduction of areas of secondary vegetation that were replaced by pasture, oil palm and general agriculture. Oil palm areas had a lower average monthly sediment yield in the rainiest period in all simulated years, compared with areas of general agriculture and pasture.

Development of Leaves in Oil Palm (Elaeis Guineensis) and Determination of Leaf Opening Rate

1994 ◽  
Vol 30 (4) ◽  
pp. 467-472 ◽  
Author(s):  
C. J. Breure
Keyword(s):  
Oil Palm ◽  
Cultural Practices ◽  
Elaeis Guineensis ◽  
Rapid Expansion ◽  
Leaf Production ◽  
La Palma ◽  
Slow Expansion ◽  
Expansion Stage ◽  
The Mean

SUMMARYOil palm rachis length was determined on primordia dissected from palms planted at four densities. It started to increase rapidly in leaf–10, that is, about ten leaves younger than the spear leaf in all density treatments. The mean number of leaf primordia at the three higher palm densities was 47.7 compared with 51.5 at the lowest density of 56 palms ha-1. Some of the palms planted at the highest density were thinned to identify the stage at which the amount of light affected the rate of leaf opening. A sudden increment of light accelerated leaf production at both the rapid expansion stage and the preceding slow expansion stage. The greatest acceleration of leaf production began 24 months after thinning, probably because of the effect of the extra light on the rate of leaf initiation. The response of leaf production to thinning may apply to other related cultural practices.Desarrollo de hojas en la palma aceitera (Elaeis guineensis) y determination de la tasa de apertura de las hojas

scholarly journals Impact of Oil Palm (Elaeis guineensis) Cultivation on Soil Physico-Chemical Properties and Food Security of Rural Households within Mundemba Sub-division, Cameroon

2021 ◽  
pp. 32-46
Author(s):  
Usongo P. Ajonina ◽  
Bekumaka B. Okanyene
Keyword(s):  
Food Security ◽  
Soil Properties ◽  
Oil Palm ◽  
Crop Production ◽  
Elaeis Guineensis ◽  
Arable Land ◽  
Rapid Expansion ◽  
Significant Deterioration ◽  
Household Heads ◽  
The Impact

Oil palm cropping is rapidly expanding within Mundemba. Although they have the potential to contribute to employment and economic development, the effect of their rapid expansion on soil properties and food security is largely unknown. The objective of the study is to analyze the trend in the surface area occupied by palms and farmlands between 1980 to 2020, assess the impact of oil palm cultivation on soil properties and food security. Ground Control Points (GCPs) were taken to evaluate land-use changes and soil samples were collected from palm plantations for analysis. Interviews and questionnaires were administered to household heads to gather information on food security. Results revealed that palm plantations experienced a rapid increase from 35.52ha in 1980 to 119,171.49 in 2020. Arable land also shows a progressive increase of 101.39 ha in 1980 to 518.55 ha in 2020. A significant deterioration of soil nutrients status under palm plantations compared to the adjacent farm lands was observed. Palm cultivation has resulted in food security issues in the area due to its lucrative nature and impact on soils properties. To improve food security farmers should be educated on sustainable crop production methods and soil management techniques.

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