scholarly journals Assessing the feasibility of forest plantation of native species: A case study of Agathis dammara and Eusideroxylon zwageri in Balikpapan, East Kalimantan, Indonesia

2019 ◽  
Vol 20 (9) ◽  
Author(s):  
Budi Setiawan ◽  
Abubakar M. Lahjie ◽  
Syahrir Yusuf ◽  
Yosep Ruslim

Abstract. Setiawan B, Lahjie AM, Yusuf S, Ruslim Y. 2019. Assessing the feasibility of forest plantation of native species: A case study of Agathis dammara and Eusideroxylon zwageri in Balikpapan, East Kalimantan, Indonesia. Biodiversitas 20: 2453-2461. Plantation forest using native species is very important effort to support biodiversity conservation. Still, analysis on its feasibility is needed to guarantee the sustainable forest management. The research aims were to assess the feasibility of plantation forestry of Agathis dammara and Eusideroxylon zwageri based on production models and financial simulation of stands management. The production models were developed based on plantation forests in Balikpapan, East Kalimantan, Indonesia. Using these plantation we developed models to estimate tree volume, total volume per hectare, Mean Annual Volume Increment (MAI) and Current Annual Increment (CAI) for each species. Financial analyses were carried out to assess the Pay Back Period (PBP), Net Present Value (NPV), Net Benefit/Cost (B/C) Ratio, Internal Rate of Return (IRR) and Equivalent Annual Annuity (EAA). The results of production model showed that A. dammara stands would reach optimum production at the age of 25 years while that of E. zwageri at the age of 150 years. A. dammara stands produce higher MAI of 15.67 m3ha-1 year-1 and total volume of 383.72 m3ha-1 than E. zwageri with MAI 1.89 m3ha-1 year-1 and total volume of 282.78 m3ha-1. The result of financial analysis showed that A. dammara plantation had the IRR higher than the Minimum Acceptable Rate (MAR) and the Net B/C Ratio of higher than 1, while E. zwageri had the Net B/C Ratio of lower than 1. A. dammara plantation also had a positive NPV value of IDR 78,699,974 while E. zwageri plantation had a negative NPV value of IDR 91,439,292. These results suggest that developing A. dammara plantation is more desirable than E. zwageri plantation.

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.


Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 462
Author(s):  
Enrico Ruzzier ◽  
Andrea Galli ◽  
Luciano Bani

Detecting and monitoring exotic and invasive Coleoptera is a complex activity to implement, and citizen science projects can provide significant contributions to such plans. Bottle traps are successfully used in wildlife surveys and can also be adapted for monitoring alien species; however, a sustainable, large scale trapping plan must take into account the collateral catches of native species and thus minimize its impact on local fauna. In the present paper, we tested the use of bottles baited with standard food products that can be purchased in every supermarket and immediately used (apple cider vinegar, red wine, and 80% ethyl alcohol) in capturing exotic and invasive beetles in the area surrounding Malpensa Airport (Italy). In particular, we reduced the exposition type of the traps in each sampling round to three days in order to minimize native species collecting. We found a significant effect of the environmental covariates (trap placement, temperature, humidity, and forest type) in affecting the efficiency in catching target beetles. Nearly all invasive Nitidulidae and Scarabaeidae known to be present in the area were captured in the traps, with apple cider vinegar usually being the most effective attractant, especially for the invasive Popillia japonica.


2001 ◽  
Author(s):  
Albertus Retnanto ◽  
Ben Weimer ◽  
I Nyoman Hari Kontha ◽  
Heru Triongko ◽  
Azriz Azim ◽  
...  

2021 ◽  
Author(s):  
Adekunle Tirimisiyu Adeniyi ◽  
Miracle Imwonsa Osatemple ◽  
Abdulwahab Giwa

Abstract There are a good numbers of brown hydrocarbon reservoirs, with a substantial amount of bypassed oil. These reservoirs are said to be brown, because a huge chunk of its recoverable oil have been produced. Since a significant number of prominent oil fields are matured and the number of new discoveries is declining, it is imperative to assess performances of waterflooding in such reservoirs; taking an undersaturated reservoir as a case study. It should be recalled that Waterflooding is widely accepted and used as a means of secondary oil recovery method, sometimes after depletion of primary energy sources. The effects of permeability distribution on flood performances is of concerns in this study. The presence of high permeability streaks could lead to an early water breakthrough at the producers, thus reducing the sweep efficiency in the field. A solution approach adopted in this study was reserve water injection. A reverse approach because, a producing well is converted to water injector while water injector well is converted to oil producing well. This optimization method was applied to a waterflood process carried out on a reservoir field developed by a two - spot recovery design in the Niger Delta area of Nigeria that is being used as a case study. Simulation runs were carried out with a commercial reservoir oil simulator. The result showed an increase in oil production with a significant reduction in water-cut. The Net Present Value, NPV, of the project was re-evaluated with present oil production. The results of the waterflood optimization revealed that an increase in the net present value of up to 20% and an increase in cumulative production of up to 27% from the base case was achieved. The cost of produced water treatment for re-injection and rated higher water pump had little impact on the overall project economy. Therefore, it can conclude that changes in well status in wells status in an heterogenous hydrocarbon reservoir will increase oil production.


2021 ◽  
Author(s):  
Wildan S. Adwin Pratama ◽  
Pegi Melati ◽  
Dipa U. Nancah ◽  
Filman Firdausman ◽  
Rizky Satriawan ◽  
...  

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