Takakazu Yumoto
Kyoto University, Primate Research Institute, Faculty Member
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To reconstruct the history of forest loss in Cambodia, the literature and national/provincial statistics of landuse patterns and the socio-economic situation were investigated. Forest cover in the 1960s was 73.3 % (13.3 Mha). However,... more
To reconstruct the history of forest loss in Cambodia, the literature and national/provincial statistics of landuse patterns and the socio-economic situation were investigated. Forest cover in the 1960s was 73.3 % (13.3 Mha). However, this drastically decreased to 47.3% (8.6 Mha) in 2016. In the 1960s, the forest was less-disturbed. From 1970 to 1993, the forest was lost gradually owing to the political instability caused by the Cambodian Civil War. In the post-war reconstruction period from 1993 to around 2002, the need for reconstruction, international demand for timber, and forest logging concessions led to a significant increase in timber production. In the rapid economic growth period from 2002 until present, while several political actions were taken to combat rapid deforestation, economic land concessions, which promoted agroindustrial plantations, as well as small-scale agriculture has been leading to the rapid expansion of arable land and deforestation since 2009.
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In Chapter 3, the direct and indirect drivers and current status of satoyama and satoumi were discussed. In this chapter, we will describe how the changes in satoyama and satoumi ecosystem services have affected biodiversity and human... more
In Chapter 3, the direct and indirect drivers and current status of satoyama and satoumi were discussed. In this chapter, we will describe how the changes in satoyama and satoumi ecosystem services have affected biodiversity and human well-being. Based on these changes, we will review why change in satoyama and satoumi is a concern.
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... Table 1. Frequency and abundances of plant seed recorded in the dung of Asian elephants (Elephas maximus) in Khao Yai National Park ... Fallen fig consumption by elephants around large strangler figs has been recorded for at least two... more
... Table 1. Frequency and abundances of plant seed recorded in the dung of Asian elephants (Elephas maximus) in Khao Yai National Park ... Fallen fig consumption by elephants around large strangler figs has been recorded for at least two fig species (Ficus altissima and F. cf. ...
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ABSTRACT
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Abstract;Seed dispersal by animals plays a crucial role in the tropics. Fruit-bearing plants serve not only as nutritional sources for frugivores, but also as seed sources for forest regeneration and as important foci for the... more
Abstract;Seed dispersal by animals plays a crucial role in the tropics. Fruit-bearing plants serve not only as nutritional sources for frugivores, but also as seed sources for forest regeneration and as important foci for the re-establishment of other plant species by attracting seed-...
Research Interests: Tropics and National Park
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Abstract The fruiting phenology of animal-dispersed plants was observed in a warm temperate, evergreen forest on Yakushima Island. The number of ripe fruits was counted for 22 trees, four lianas and one parasitic epiphyte species with... more
Abstract The fruiting phenology of animal-dispersed plants was observed in a warm temperate, evergreen forest on Yakushima Island. The number of ripe fruits was counted for 22 trees, four lianas and one parasitic epiphyte species with sapfruit. These fruits were ...
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Abstract;The fruit visitation patterns of small mammals were investigated by camera trappings on the forest floor in a tropical seasonal forest of Thailand. A total of 3,165 visits were recorded for seven small mammal species. The four... more
Abstract;The fruit visitation patterns of small mammals were investigated by camera trappings on the forest floor in a tropical seasonal forest of Thailand. A total of 3,165 visits were recorded for seven small mammal species. The four Muridae species, Rattus remotus, Niviventer ...
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... et al. 2004), and spatial autocorrela-tion within a few to tens of meters (Murakami 1989; Fuki-haru and Kato 1997). On ... et al. 2001), tree distri-bution patterns (Nagamatsu and Miura 1997; Harms et al. 2001; Tsujino et al. 2006 ...
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... That is, opportunist insects, such as small bees and syrphid flies playing an important role in the pollination of canopy-flower-ing species, tended to stay in the sunny area above the canopy and did not forage below the canopy layer... more
... That is, opportunist insects, such as small bees and syrphid flies playing an important role in the pollination of canopy-flower-ing species, tended to stay in the sunny area above the canopy and did not forage below the canopy layer where it is dark and cool. ...
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Futurability is derived from the German zukunft (future) and fahigkeit (potential or ability). "Sustainability" and "sustainable development" are globally recognized modern terms. However, both of these include the... more
Futurability is derived from the German zukunft (future) and fahigkeit (potential or ability). "Sustainability" and "sustainable development" are globally recognized modern terms. However, both of these include the meaning of "maintaining the current status quo". Yet, there can be no future for mankind if the aim is to prolong the current situation which our world is confronted by environmental problems. Therefore, RIHN uses the word "futurability" to encapsulate a viewpoint in which we consider how the future environment should be, and from there examine the present to find what actions should be undertaken now to reach the future. Thus, "futurability" is an important research guideline for RIHN. This is a PowerPoint educational presentation for university students taking general subjects. The 11 chapters (500 slides) contain text photos and illustrations in an easy-to-understand yet comprehensive presentation about biodiversity fro...
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Introduction Seed dispersal is a critical stage in a plant’s reproductive cycle for the purpose of establishing new populations. The process of seed dispersal not only enhances the fitness of the maternal plant (reviewed by Howe and... more
Introduction Seed dispersal is a critical stage in a plant’s reproductive cycle for the purpose of establishing new populations. The process of seed dispersal not only enhances the fitness of the maternal plant (reviewed by Howe and Smallwood 1982; Willson and Traveset 2000), but also has a direct effect on the genetic structure of plant populations (Hamrick et al. 1993). Diaspores have many adaptations that enhance long-distance seed dispersal by using vectors such as wind, water, and animals. However, a large proportion of plants in most communities are dispersed by animals (Howe and Smallwood 1982). Therefore, seed dispersal by animals is considered to play an important role in the genetic structure of plant populations and the maintenance of biodiversity within forests. Large frugivores are effective seed dispersers quantitatively, but they are extremely sensitive to habitat modifications caused by human activity. If plant species depend only on large frugivorous animals for see...
A population census of chimpanzees (Pan troglodytes schweinfurthil) was conducted in the original part of Kahuzi-Biega National Park. Zaire. The census provides the first estimate of the density of chimpanzees in montane forests of... more
A population census of chimpanzees (Pan troglodytes schweinfurthil) was conducted in the original part of Kahuzi-Biega National Park. Zaire. The census provides the first estimate of the density of chimpanzees in montane forests of Equatorial Africa. At least three unit groups of chimpanzees were identified in the census area during the 1990 bamboo season. The estimated density (0.13 chimpanzees/km2) falls within the range of densities in savanna. the driest chimpanzee habitat. The estimated density was far lower than the density of gorillas that sympatrically inhabit this montane forest, even though the two apes have been found at almost equal density in tropical forests in other areas. Chimpanzees were typical forest-dwellers, but goriiias ranged over various types of vegetation, including the open vegetation and the swamp. The low diversity and availability of fruits in the montane forest are responsible for the low density of chimpanzees who are frugivorous in various habitats. ...
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Il a ete prouve par une methode mathematique que pendant le stade initial de l'immersion de l'orge, il se produit une absorption de l'eau extremement rapide pendant laquelle le pericarpe et les tests sont satures par... more
Il a ete prouve par une methode mathematique que pendant le stade initial de l'immersion de l'orge, il se produit une absorption de l'eau extremement rapide pendant laquelle le pericarpe et les tests sont satures par imbibition capillaire et la diffusion physique dans l'embryon y fait suite. Les coefficients de diffusion et l'energie de l'activation de l'orge Fuji Nijo II ont ete evalues. En ce qui concerne d'autres varietes d'orge, la duree initiale appropriee peut etre evaluee en theorie selon la temperature de trempe, en utilisant le taux de consommation d'oxygene a titre d'indication de l'activite de l'orge
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Mixed dipterocarp forests in Sarawak are the richest tropical rain forests in the world with high diversity in tree species. Unstable, global environmental changes such as the El Niño Southern Oscillation have a strong influence on... more
Mixed dipterocarp forests in Sarawak are the richest tropical rain forests in the world with high diversity in tree species. Unstable, global environmental changes such as the El Niño Southern Oscillation have a strong influence on tropical rain forests of Sarawak as well as other regions of Southeast Asia. Research in the Canopy Biology Program in Sarawak, aims to clarify firstly that unstable environmental changes at the global level influence phenology and reproductive systems of trees studied, and secondly, that life history ...
Pollination ecology of an emergent tree species, Shorea (section Mutica) parvifolia (Dipterocarpaceae), was studied using the canopy observation system in a lowland dipterocarp forest in Sarawak, Malaysia, during a general flowering... more
Pollination ecology of an emergent tree species, Shorea (section Mutica) parvifolia (Dipterocarpaceae), was studied using the canopy observation system in a lowland dipterocarp forest in Sarawak, Malaysia, during a general flowering period in 1996. Although the species has been reported to be pollinated by thrips in Peninsular Malaysia, our observations of flower visitors and pollination experiments indicated that beetles (Chrysomelidae and Curculionidae, Coleoptera) contributed to pollination of S. parvifolia in Sarawak. Beetles accounted for 74% of the flower visitors collected by net-sweeping, and 30% of the beetles carried pollen, while thrips accounted for 16% of the visitors, and 12% of the thrips carried pollen. The apical parts of the petals and pollen served as a reward for the beetles. Thrips stayed inside the flower almost continuously after arrival, and movements among flowers were rare. Fruit set was significantly increased by introduction of beetles to bagged flowers, ...
One of the goals for primate feeding ecology is to understand the factors that affect inter- and intra-specific variations. Therefore, a detailed description of basic feeding ecology in as many populations as possible is necessary and... more
One of the goals for primate feeding ecology is to understand the factors that affect inter- and intra-specific variations. Therefore, a detailed description of basic feeding ecology in as many populations as possible is necessary and warrants further understanding. The black-and-white colobus (Colobus guereza) or guereza is widely distributed in Africa and is one of the well-studied colobines in terms of their feeding; they demonstrate considerable variation in their diets in response to local conditions. We studied the diet of a group of guerezas in the Kalinzu Forest, Uganda, for over 30 consecutive months using behavioral observation (4308 h in total), phenology, and vegetation surveys. A total of 31 plant species were consumed by the study group. This study group was predominantly folivorous; the majority of their feeding time was involved in feeding on young leaves (87%). However, during certain times of the year, fruits and seeds accounted for 45% of monthly feeding time. Young leaves of Celtis durandii were by far the most important food, which constituted 58% of the total feeding records. There was a significant increase in the consumption of fruits and flowers once young leaf availability was low, but their consumption of fruits did not significantly increase even when fruit availability was high. Their monthly dietary diversity increased as the number of available plants with young leaves declined, suggesting that much of the dietary diversity in the study group may be attributable to the young leaf portion of their diet. Our findings may help contribute to a better understanding of the dietary adaptations and feeding ecology of guerezas in response to local environmental conditions.
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Abstract. We aimed to validate a method to identify age class and sex of sika deer (Cervus nippon), which defecate fecal pellets. We collected 42 and 54 fecal samples in Nara and Yakushima, respectively. Both pellet width and length were... more
Abstract. We aimed to validate a method to identify age class and sex of sika deer (Cervus nippon), which defecate fecal pellets. We collected 42 and 54 fecal samples in Nara and Yakushima, respectively. Both pellet width and length were significantly larger for adults than juveniles (1∼1.5 yrs). A discriminant model based on both width and length correctly assigned an age class for 92% of individuals in Nara and 98% in Yakushima. We genetically determined their sex based on the gel electrophoresis of two genes on sex chromosomes (SRY and ZFX/Y) amplified by PCR. For fresh feces, sex was not determined for 40% of the samples, but for the rest of the samples, sex was correctly assigned in almost all cases (28/29). However, sex was not determined in any of the samples that were analyzed at a half month or later after defecation. The proportion of young individuals could be estimated by the morphometry of fecal pellets, but the sex of the animals could not be confirmed.