scholarly journals Modeling climatic suitable areas for kedondong (Spondias dulcis) cultivation in central part of Sumatra, Indonesia

2019 ◽  
Vol 20 (12) ◽  
Author(s):  
Ibna Hayati ◽  
Alex Hartana ◽  
Nina Ratna Djuita

Abstract. Hayati I, Hartana A, Djuita NR. 2019. Modeling climatic suitable areas for kedondong (Spondias dulcis) cultivation in central part of Sumatra, Indonesia. Biodiversitas 20: 3608-3618. Kedondong (Spondias dulcis Parkinson) is a fruit plant native to Society Island (Polynesia, Pacific Islands) and widely cultivated in many tropical regions and countries. However, little is known about the occurrences and potential distribution of kedondong as well as its adaptability to different climate particularly in central part Sumatra. This paper is the first to predict the distribution of kedondong in central part of Sumatra in spatially explicit way. The maximum entropy (MaxEnt) model was used to analyze the geographical distribution of kedondong and to map its climatically suitable habitat in central part of Sumatra. The results showed that the MaxEnt model can be used to predict the climatic suitable areas for kedondong cultivation. Notably, the extent of the potentially suitable habitat was significantly larger than the present occurrence of kedondong in central part of Sumatra. The most suitable areas identified in this study covered the west coast of Sumatra and the central part of Sumatra but did not reach the eastern coast. They included parts of Kuantan Singingi, Indragiri Hulu, Indragiri Hilir and Pelalawan of Riau Provinces, Batang Hari of Jambi Provinces, and western part which include Agam, Tanah Datar, West Pasaman, Limapuluh Kota, Padang Pariaman, Padang and South Pesisir of West Sumatra Provinces. The MaxEnt model performed better than random method with an Area Under Curve (AUC) value of 0.981. Although kedondong is still largely ignored by scientific community and its potential has not been deeply explored, the findings of this study imply that it is very important to develop kedondong germplasm resources which have adaptability to extreme climate in central part of Sumatra.

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Gunawan Gunawan ◽  
Muhammad Ikhwan Rizki ◽  
Olivia Anafarida ◽  
Nurul Mahmudah

Abstract. Gunawan, Rizki MI, Anafarida O, Mahmudah N. 2021. Modeling potential distribution of Baccaurea macrocarpa in South Kalimantan, Indonesia. Biodiversitas 22: 3230-3236. Baccaurea macrocarpa is fruit tree that has a potential source of food and medicine. However, little is known about the occurrences and potential distribution of B. macrocarpa mainly in South Kalimantan. This study is the first to predict the distribution of B. macrocarpa in South Kalimantan using maximum entropy (MaxEnt). Modeling included 102 occurrence records with 19 bioclimatic variables, solar radiation, altitude, and slope. Temperature, solar radiation, and precipitation were the key environmental factor influencing the distribution of B. macrocarpa. The district of HS (Hulu Sungai Selatan), HT (Hulu Sungai Tengah), HU (Hulu Sungai Utara), BL (Balangan), and TG (Tabalong) were predicted as highly suitable areas (IHS 0.6-1) for this species. The MaxEnt model performed better than the random method with an Area Under Curve (AUC) value of 0.817, indicating that the model is good and informative model for habitat suitability of B. macrocarpa. The predicted model we presented here can help habitat conservation, biodiversity conservation planning and monitoring, and cultivation in the future for B. macrocarpa.


2014 ◽  
Vol 651-653 ◽  
pp. 1496-1503 ◽  
Author(s):  
Jin Song Dai ◽  
Fu Liang Cao

Maximum entropy (Maxent) modeling was used to predict the potential climate habitat distribution of Chinese hybrid poplar (clone I-63, I-69 and I-72). Occurrence data were collected from literatures. The Maxent model performed better than random with an average cross-validated AUC value of 0.96. Under the three future climate scenarios (emission scenarios A1B, A2 and B1), the geographic distribution of suitable habitat would shift from southwest to northeast, the suitable habitat area of scenario A1B increased most compared to other two, the ranking of the loss habitat area was scenario B1 > scenario A2 > scenario A1B, and the gain habitat area was scenario A1B > scenario A2 > scenario B1. The results of this work could be used as scientific basis for adapting and mitigating Chinese hybrid poplar planting to a climate change.


2009 ◽  
Vol 19 (1) ◽  
pp. 63-76 ◽  
Author(s):  
BORIS A. TINOCO ◽  
PEDRO X. ASTUDILLO ◽  
STEVEN C. LATTA ◽  
CATHERINE H. GRAHAM

SummaryThe Violet-throated MetaltailMetallura baroniis a high altitude hummingbird endemic to south-central Ecuador currently considered globally ‘Endangered’. Here we present the first detailed assessment of its distribution, ecology and conservation. We first used a maximum entropy model (Maxent model) to create a predicted distribution for this species based on very limited species occurrence data. We used this model to guide field surveys for the species between April and October 2006. We found a positive relationship between model values and species presence, indicating that the model was a useful tool to predict species occurrence and guide exploration. In the sites where the metaltail was found we gathered data on its habitat requirements, food resources and behaviour. Our results indicate that Violet-throated Metaltail is restricted to the Western Cordillera of the Andes Mountains in Azuay and Cañar provinces of Ecuador, with an area of extent of less than 2,000 km2. Deep river canyons to the north and south, lack of suitable habitat, and potential interspecific competition in the east may limit the bird's distribution. The species occurred in three distinct habitats, includingPolylepiswoodland, the upper edge of the montane forest, and in shrubby paramo, but we found no difference in relative abundance among these habitats. The metaltail seems to tolerate moderate human intervention in its habitats as long as some native brushy cover is maintained. We found thatBrachyotumsp.,Berberissp., andBarnadesiasp. were important nectar resources. The ‘Endangered’ status of this species is supported due to its restricted distribution in fragmented habitats which are under increasing human pressures.


Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 490
Author(s):  
Habibon Naher ◽  
Hassan Al-Razi ◽  
Tanvir Ahmed ◽  
Sabit Hasan ◽  
Areej Jaradat ◽  
...  

Tropical forests are threatened worldwide due to deforestation. In South and Southeast Asia, gibbons (Hylobatidae) are important to seed dispersal and forest regeneration. Most gibbons are threatened due to deforestation. We studied the western hoolock gibbon (Hoolock hoolock) in Bangladesh to determine population size and extent of suitable habitat. We used distance sampling to estimate density across 22 sites in northeastern and southeastern Bangladesh. We used Maxent modeling to determine areas of highly suitable habitat throughout Bangladesh. Density was estimated to be 0.39 ± 0.09groups/km2, and the total estimated population was 468.96 ± 45.56 individuals in 135.31 ± 2.23 groups. The Maxent model accurately predicted gibbon distribution. Vegetation cover, isothermality, annual precipitation, elevation and mean temperature of the warmest quarter influenced distribution. Two areas in the northeast and two areas in the southeast have high potential for gibbon conservation in Bangladesh. We also found significantly more gibbons in areas that had some level of official protection. Thus, we suggest careful evaluation, comprehensive surveys and restoration of habitats identified as suitable for gibbons. We recommend bringing specific sites in the northeastern and southeastern regions under protection to secure habitat for remaining gibbon populations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiming Liu ◽  
Lianchun Wang ◽  
Caowen Sun ◽  
Benye Xi ◽  
Doudou Li ◽  
...  

AbstractSapindus (Sapindus L.) is a widely distributed economically important tree genus that provides biodiesel, biomedical and biochemical products. However, with climate change, deforestation, and economic development, the diversity of Sapindus germplasms may face the risk of destruction. Therefore, utilising historical environmental data and future climate projections from the BCC-CSM2-MR global climate database, we simulated the current and future global distributions of suitable habitats for Sapindus using a Maximum Entropy (MaxEnt) model. The estimated ecological thresholds for critical environmental factors were: a minimum temperature of 0–20 °C in the coldest month, soil moisture levels of 40–140 mm, a mean temperature of 2–25 °C in the driest quarter, a mean temperature of 19–28 °C in the wettest quarter, and a soil pH of 5.6–7.6. The total suitable habitat area was 6059.97 × 104 km2, which was unevenly distributed across six continents. As greenhouse gas emissions increased over time, the area of suitable habitats contracted in lower latitudes and expanded in higher latitudes. Consequently, surveys and conservation should be prioritised in southern hemisphere areas which are in danger of becoming unsuitable. In contrast, other areas in northern and central America, China, and India can be used for conservation and large-scale cultivation in the future.


2018 ◽  
Vol 43 ◽  
pp. 111-116
Author(s):  
Mustapha Hassoun ◽  
Hanaa Moussa ◽  
Ghizlane Salhi ◽  
Hanaa Zbakh ◽  
Hassane Riadi ◽  
...  

AbstractWe report new records and corological data for three Moroccan marine macroalgae that complete their distribution information. Radicilingua thysanorhizans is new record for Morocco; Champia compressa is recorded for the first time from the eastern coast of the Atlantic Ocean. Diplothamnion jolyi is widely distributed in the western coast of the Atlantic coast and Pacific Islands, and recently reported from the Mediterranean Sea; this new record from Moroccan Atlantic coast extends their distribution range.Key words: Algae, Atlantic Ocean, Champia compressa, Diplothamnion jolyi, Radicilingua thysanorhizans.ResumenSe aportan nuevos registros y datos corológicos para tres macroalgas marinas de Marruecos, que completan la información sobre su distribución. Radicilingua thysanorhizans es cita nueva para Marruecos. Champia compressa se registra por la primera vez en la costa oriental del Océano Atlántico. Diplothamnion jolyi se distribuye ampliamente en la costa occidental de la costa atlántica y las islas del Pacífico y ha sido recientemente citada en el mar Mediterráneo; esta nueva cita para costa Atlántica Marroquí amplia su rango de distribución.Palabras clave: Algae, Océano Atlántico, Champia compressa, Diplothamnion jolyi, Radicilingua thysanorhizans.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7920
Author(s):  
Sarah Cunze ◽  
Judith Kochmann ◽  
Lisa K. Koch ◽  
Elisa Genthner ◽  
Sven Klimpel

Background Zika is of great medical relevance due to its rapid geographical spread in 2015 and 2016 in South America and its serious implications, for example, certain birth defects. Recent epidemics urgently require a better understanding of geographic patterns of the Zika virus transmission risk. This study aims to map the Zika virus transmission risk in South and Central America. We applied the maximum entropy approach, which is common for species distribution modelling, but is now also widely in use for estimating the geographical distribution of infectious diseases. Methods As predictor variables we used a set of variables considered to be potential drivers of both direct and indirect effects on the emergence of Zika. Specifically, we considered (a) the modelled habitat suitability for the two main vector species Aedes aegypti and Ae. albopictus as a proxy of vector species distributions; (b) temperature, as it has a great influence on virus transmission; (c) commonly called evidence consensus maps (ECM) of human Zika virus infections on a regional scale as a proxy for virus distribution; (d) ECM of human dengue virus infections and, (e) as possibly relevant socio-economic factors, population density and the gross domestic product. Results The highest values for the Zika transmission risk were modelled for the eastern coast of Brazil as well as in Central America, moderate values for the Amazon basin and low values for southern parts of South America. The following countries were modelled to be particularly affected: Brazil, Colombia, Cuba, Dominican Republic, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Mexico, Puerto Rico and Venezuela. While modelled vector habitat suitability as predictor variable showed the highest contribution to the transmission risk model, temperature of the warmest quarter contributed only comparatively little. Areas with optimal temperature conditions for virus transmission overlapped only little with areas of suitable habitat conditions for the two main vector species. Instead, areas with the highest transmission risk were characterised as areas with temperatures below the optimum of the virus, but high habitat suitability modelled for the two main vector species. Conclusion Modelling approaches can help estimating the spatial and temporal dynamics of a disease. We focused on the key drivers relevant in the Zika transmission cycle (vector, pathogen, and hosts) and integrated each single component into the model. Despite the uncertainties generally associated with modelling, the approach applied in this study can be used as a tool and assist decision making and managing the spread of Zika.


1969 ◽  
Vol 38 (2) ◽  
pp. 96-104
Author(s):  
L. Rivera-Brenes ◽  
J. I. Cabrera ◽  
L. F. Colón

A grazing trial was carried out at Yabucoa, on the eastern coast of Puerto Rico to determine the usefulness for this purpose of several grasses and a grass-legume mixture. It followed the same pattern and procedure as those which had been performed previously at the Main Station Farm located in the northern humid section of the Island. In the trial, which lasted for 2 years, Pangola grass, Pará grass, St. Augustine grass, and a Guinea grass-tropical kudzu combination were compared as to carrying capacity and other characters to determine their pasture values. The carrying capacities of these grasses were as follows: Pangola, 1.12; Guinea-tropical kudzu, 1.42; St, Augustine, 1.23; and Para grass, 0.87 head per acre. The gross returns per acre for the first year were, $118, $137, $97, and $87, respectively. For the second year they were: $159, $179, $124, and $68, respectively. Besides the information obtained on the carrying capacity of the pastures, the results show that well-managed pastures are at least as profitable as many of the cash crops actually grown in the Island. This does not take into consideration additional soil- and water-conservation benefits which accrue from having the soil covered by a sod. Pangola and St. Augustine grasses are good pasture crops that can be used in the eastern coastal region satisfactorily. The Guinea-tropical kudzu mixture, however, is better than these grasses by themselves. The superiority of the legume-grass combination was again demonstrated by the results of this experiment. Pará grass was not well adapted for grazing in the light soil in which the experiment was planted.


2021 ◽  
Vol 748 (1) ◽  
pp. 012025
Author(s):  
R Reswati ◽  
BP Purwanto ◽  
R Priyanto ◽  
W Manalu ◽  
R I Arifiantini

Abstract The swamp buffalo population in West Sumatra Province decline continuously due to the low female reproductive performance. This research was conducted to identify female buffalo reproductive performance, which could be used as baseline data to enhance its population growth. A survey research method was conducted in two subdistricts, namely Lubuk Basung and Matur, located at different altitudes. Data were collected by interviewing farmers and observing their farms. The parameters observed were age at first mating, age at first calving, calving interval, service per conception, and buffalo farming practices. Significant differences in reproductive performances of female buffalo were observed. Age at first mating 39.04 ± 9.91 and 33.67 ± 5.3 mo., age at first calving 51.61 ± 9.95 and 45.71 ± 5.58 mo., calving interval 27.26 ± 8.84 and 24.17 ± 7.06 mo., and services per conception 1.82 ± 0.82 and 1.55 ± 0.78 were represented buffalo in Lubuk Basung and Matur, respectively. The buffalo reproductive performances in both locations were not optimal; however, Matur’s buffalo reproductive performances were better than those in Lubuk Basung due to its better farming practices and more comfort climatic conditions. Therefore, improving farming practice is essential to enhance buffalo’s reproductive performance and population growth.


2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Bo Liu

Differential search algorithm (DS) is a relatively new evolutionary algorithm inspired by the Brownian-like random-walk movement which is used by an organism to migrate. It has been verified to be more effective than ABC, JDE, JADE, SADE, EPSDE, GSA, PSO2011, and CMA-ES. In this paper, we propose four improved solution search algorithms, namely “DS/rand/1,” “DS/rand/2,” “DS/current to rand/1,” and “DS/current to rand/2” to search the new space and enhance the convergence rate for the global optimization problem. In order to verify the performance of different solution search methods, 23 benchmark functions are employed. Experimental results indicate that the proposed algorithm performs better than, or at least comparable to, the original algorithm when considering the quality of the solution obtained. However, these schemes cannot still achieve the best solution for all functions. In order to further enhance the convergence rate and the diversity of the algorithm, a composite differential search algorithm (CDS) is proposed in this paper. This new algorithm combines three new proposed search schemes including “DS/rand/1,” “DS/rand/2,” and “DS/current to rand/1” with three control parameters using a random method to generate the offspring. Experiment results show that CDS has a faster convergence rate and better search ability based on the 23 benchmark functions.


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