scholarly journals Akaike model selections of the vegetation structures and aerosphere factors in supporting lesser short nosed fruit bat (Cynopterus brachyotis Muller, 1838) populations in Asia mountainous paddy fields

2021 ◽  
Author(s):  
Adi Basukriadi ◽  
Erwin Nurdin ◽  
Andri Wibowo ◽  
Jimi Gunawan

AbstractAs an aerial and arboreal fauna, the abundances and populations of fruit bat Cynopterus brachyotis were influenced by the vegetation structures and aerosphere condition variables of fruit bat ecosystems. While mountaineous paddy field is an unique habitat since the trees are scarce and has exposure to the aerosphere variables including air temperature and humidity. Here this paper aims to select the best vegetation structures and aerosphere factors that support the abundance of C. brachyotis in mountainous paddy field landscape in West Java. The model selection was using AIC methodology by testing 15 models including 5 single models and 10 combination models of explanatory variables. Based on the model, tree height and combinations of tree height and elevation produced the best prediction for the bat abundances, as described by low values of AIC and the highest values of R2 and adjusted R2. For the best models, the AIC values ranged from 16.674 to 17.603, from 0.3404 to 0.4144 (R2), and 0.2461 to 0.2192 for adjusted R2. Regarding conservation of C. brachyotis and learning from the model, the conservation approaches mainly in mountainous paddy fields are encouraged to protect and conserve high altitude landscapes and trees with height > 10 m. Whereas the AIC results show lack of aerosphere variable effects on C. brachyotis (AIC: 19.346-20.406, R2: 0.1124-0.001353, and adjusted R2: −0.01444 − −0.1413).

2021 ◽  
Author(s):  
Adi Basukriadi ◽  
Erwin Nurdin ◽  
Andri Wibowo ◽  
Jimi Gunawan

AbstractBat is animal that occupies aerosphere, especially fruit bats that forage on the space around the trees. The fruit bats use whether narrow space below tree canopy or in edge space on the edge of canopy. Whereas the aerosphere occupancy of fruits bats related to the specific tree species is poorly understood. Here, this paper aims to assess and model the association of fruit bat Cynopterus brachyotis aerosphere occupancy (Ψ) with tree species planted in mountainous paddy fields in West Java. The studied tree species including Alianthus altissima, Acacia sp., Cocos nucifera, Mangifera indica, Pinus sp., and Swietenia macrophylla. The result shows that the tree species diversity has significantly (x2= 27.67, P < 0.05) affected the C. brachyotis aerosphere occupancy. According to values of Ψ and occupancy percentage, high occupancy of narrow space by C. brachyotis was observed in Swietenia macrophylla (Ψ = 0.934, 78%), followed by Alianthus altissima (Ψ = 0.803, 57%), and Mangifera indica (Ψ = 913, 55%). While high occupancy of edge space was observed in Mangifera indica (Ψ = 0.685, 41%), followed by Pinus sp. (Ψ = 0.674, 38%), and Alianthus altissima sp. (Ψ = 0.627, 36%). The best model for explaining C. brachyotis occupation in narrow space is the tree height with preferences on high tree (Ψ~tree height, AIC = 1.574, R2= 0.5535, Adj. R = 0.4047). While for edge space occupant, the best model is also the tree height (Ψ~tree height, AIC = −26.1510, R2= 0.7944, Adj. R = 0.7258).


2015 ◽  
Vol 76 (15) ◽  
Author(s):  
Yanyan Wang ◽  
Hiroki Oue ◽  
Sanz Grifrio Limin ◽  
Sartika Laban

Several studies have suggested the spikelet fertility would be significantly damaged if the air temperature (Ta) was high at heading and flowering stage. In this study, we evaluated the effect of water ponding in two paddy fields to decrease leaf temperature (Tl) and panicle temperature (Tp) during the 2014 growing season. Within the first conventionally water managed paddy field (cultivar Akitakomachi), we set 1 m × 1 m experiment plot (Plot A1) from July 8th to August 24th, and water was put in 15 cm depth in the morning at 8:30. For expecting larger difference of leaf and panicle temperature between in and outside the plot, the plot was expended to 2 m × 2 m (Plot A2) from August 25th to September 8th, 2014, and water was put in 15 cm depth at noon. This method was also used in the plot B (2 m ×2 m) which was installed in another conventionally water managed field (cultivar Nikomaru) from September 9th to 30th, 2014. Tl and Tp were measured every two or three hours during daytime in every 10 cm canopy layer in and outside plots. In the first experimental paddy field, at largest, Tl and Tp in the plot were 4.3 ℃, 5.5 ℃ lower than Tl and Tp outside the plot, respectively. Tp was 6.6 ℃ lower than Ta under low relative humidity condition. In the second experimental paddy field, Tl and Tp in the plot were 3.6 ℃, 3.4 ℃ lower than Tl and Tp outside the plot, respectively. It revealed water ponding was a useful method to decrease leaf and panicle temperature under larger solar radiation, higher air temperature and lower relative humidity conditions at heading and flowering stage.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 353
Author(s):  
Ya-Wen Chiueh ◽  
Chih-Hung Tan ◽  
Hsiang-Yi Hsu

In the face of climate change, extreme climates are becoming more frequent. There were severe droughts in Taiwan in 2020, 2014–2015, and 2002. In these years, the paddy fields were kept fallow to save water and transfer agricultural water to non-agricultural use. On the other hand, with global warming, the existence of paddy fields may be one of the natural solutions to regional temperature mitigation. This study used remote sensing to quantify the difference in temperature between paddy fields and urban areas. The result of overall surface temperature deductive analysis revealed that the temperature in the whole Taoyuan research area was 1.2 °C higher in 2002 than in 2003 because of fallowing of the paddy field, while in the Hsinchu research area, it was 1.5 °C higher in 2002 than in 2003, due to the same reason described above. In terms of the difference in land use, for the Hsinchu research area, the surface temperature deductive result showed that the average paddy field temperature in 2002 was 22.3 °C (sample area average), which was 7.7 °C lower than that of the building and road point and 4.3 °C lower than that of the bare land point. The average paddy field temperature in 2003 was 19.2 °C (sample area average), which was 10.1 °C lower than that of the building and road point and 8.3 °C lower than that of the bare land point. Then this study evaluated the economic valuation of the paddy field cooling effect using the contingent valuation method. Through the paddy field cooling effect and in the face of worsening extreme global climate, the willingness to pay (WTP) of the respondents in Taiwan for a decrease of 1 °C with regard to the regional microclimate was evaluated. It was found that people in Taiwan are willing to pay an extra 8.89 USD/per kg rice/year for the paddy for a decrease in temperature by 1 °C in the regional microclimate due to the paddy field. Furthermore, this study applied the benefits transfer method to evaluate the value of a decrease of 1 °C in the regional microclimate in Taiwan. The value of a decrease of 1 °C in the regional microclimate in Taiwan is 9,693,144,279 USD/year. In this regard, the economic value of 1 °C must not be underestimated. In conclusion, more caution is needed while making decisions to change the land use of paddy fields to other land uses.


2020 ◽  
Vol 12 (5) ◽  
pp. 2094
Author(s):  
Di Zhao ◽  
Junyu Dong ◽  
Shuping Ji ◽  
Miansong Huang ◽  
Quan Quan ◽  
...  

Soil organic carbon (SOC) concentration is closely related to soil quality and climate change. The objectives of this study were to estimate the effects of contemporary land use on SOC concentrations at 0–20 cm depths, and to investigate the dynamics of SOC in paddy-field soil and dry-land soil after their conversion from natural wetlands (20 and 30 years ago). We investigated the dissolved organic carbon (DOC), light fraction organic carbon (LFOC), heavy fraction organic carbon (HFOC), and other soil properties (i.e., moisture content, bulk density, pH, clay, sand, silt, available phosphorous, light fraction nitrogen, and heavy fraction nitrogen) in natural wetlands, constructed wetlands, fishponds, paddy fields, and soybean fields. The results indicated that the content of DOC increased 17% in constructed wetland and decreased 39% in fishponds, and the content of HFOC in constructed wetland and fishponds increased 50% and 8%, respectively, compared with that in natural wetlands at 0–20 cm. After the conversion of a wetland, the content of HFOC increased 72% in the paddy fields and decreased 62% in the dry land, while the content of DOC and LFOC decreased in both types. In the paddy fields, LFOC and HFOC content in the topmost 0.2 m of the soil layer was significantly higher compared to the layer below (from 0.2 to 0.6 m), and there were no significant differences observed in the dry land. The findings suggest that the paddy fields can sequester organic carbon through the accumulation of HFOC. However, the HFOC content decreased 22% after 10 years of cultivation with the decrease of clay content, indicating that paddy fields need to favor clay accumulation for the purpose of enhancing carbon sequestration in the paddy fields.


PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e98093 ◽  
Author(s):  
Jorn A. Cheney ◽  
Daniel Ton ◽  
Nicolai Konow ◽  
Daniel K. Riskin ◽  
Kenneth S. Breuer ◽  
...  

2018 ◽  
Vol 16 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Junichi Kashiwagi ◽  
Koji Hamada ◽  
Yutaka Jitsuyama

AbstractDirect sowing of rice in a flooded paddy field is a beneficial cultivation practice for water use and labour efficiency, compared to the transplanted cultivation. However, a drastic reduction in seedling emergence under flooded paddy fields is a serious constraint especially when the seeds fell at deeper soil layers. Suitable rice germplasm for the direct sowing in flooded paddy fields could ensure the success of this cultivation practice. Instead of laborious field-based screening systems, a pot-based screening method was adopted for simplicity and efficient evaluation of seedling emergence of a subset of world rice germplasm (n = 75) at different sowing depths. As a result, two rice genotypes, ‘Vary Futsi’ (landrace from Madagascar, non-glutinous, subspecies Indica) and ‘Dahonggu’ (landrace from China, non-glutinous, subspecies Indica), with consistently better seedling emergence were identified from a wide range of rice germplasm. These genotypes could serve as excellent parents for the breeding program in developing new rice cultivars with the improved seedling emergence in flooded paddy fields. There were no significant differences in the seedling emergence rate in flooded paddy conditions among the groups from various agro-geographical regions.


2020 ◽  
Vol 2 (1) ◽  
pp. 48-54
Author(s):  
Mhd Zakaria

The purposes of this research are to know the level of paddy field degradation, mapping level of paddy field degradation and analyze effort of paddy field rehabilitation in Beringin Subdistrict of Deli Serdang Regency of North Sumatera Indonesia to increase rice productivity. This research was conducted in Medan Krio Village, District Sunggal Regency Deli Serdang of North Sumatera. The study was conducted in March to July 2017. This research used nonfactorial Randomized Block Design (RBD) with 5 levels organic dosage treatment of Compost Waste City, i.e: B0: Control, B1: Dose 1.5% (36,00 ton/ha), B2: Dose 3% (72,00 ton/ha), B3: Dose 4.5% (108,00 ton/ha), B4: Dose 6% (144,0 ton/ha). The parameters that will be analyzed are the physical, chemical and biological properties of soil in paddy fields. The result showed, treatment with Dose 6% (B4) can (1) improve physical properties of soil Bulk Density, Porosity and the effective depth of soil; (2) increase the C-organic content, N-Total levels of P-Available, CEC soil, and low C/N Ratio; (3) increase Soil organic matter and total Microbes. So, Treatment Dose 6% (B4) of compost waste city gives the best effect to the physical, chemical and biological properties of soil in paddy fields


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