scholarly journals Bird Community and Vegetation Structure in a Forest with a High Density of Sika Deer

2000 ◽  
Vol 48 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Teruaki HINO
DEPIK ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 84-90
Author(s):  
Sari Marina Saragi ◽  
Desrita Desrita

Highly Utilization of Mangrove field as cultivation field of fish and recreation and tour site by people have big posses to the abundance of Mangrove crab (Scylla serrata) because of mangrove play role as habitats of mangrove crabs. The research was conducted for two months from December 2016 to January 2017. This study aims to see the structure of mangrove vegetation, the abundance of Mangrove Crab and the influence of mangrove vegetation structure on the abundance of Mangrove Crab in Kampung Nipah. The results of this research are Vegetation structure of Mangrove in the station I and II show high density, whereas density in station III wide apart. The abundance of mangrove crab in the station I and II showed the higher result from station III. The Influence of Vegetation Structure of Mangrove and Abundance of Mangrove Crab can be related by using regression analysis Y = 0.0241x + 113.6. The correlation coefficient (r) that value obtained as 0.79 have a meaning the connection between mangrove density and abundance of mangrove crab are rated in the strong category that has a value 79%. The density of Mangrove to 1000 units will rise up the abundance of mangrove crab to 43.5 an individual. Tingginya pemanfaatan mangrove sebagai lahan budidaya ikan dan sebagai wisata rekreasi oleh masyarakat sangat mempengaruhi kelimpahan Kepiting Bakau (Scylla serrata) karena hutan mangrove merupakan habitat bagi Kepiting Bakau. Penelitian ini dilaksanakan selama dua bulan yaitu bulan Desember 2016 sampai Januari 2017. Penelitian ini bertujuan untuk melihat struktur vegetasi mangrove, kelimpahan Kepiting Bakau dan pengaruh struktur vegetasi mangrove terhadap kelimpahan Kepiting Bakau di Kampung Nipah. Hasil dari penelitian struktur vegetasi mangrove di stasiun I dan II memiliki kerapatan sangat padat, sedangkaan kerapatan di stasiun III jarang. Kelimpahan Kepiting Bakau di Stasiun I dan II lebih tinggi dari kelimpahan di stasiun III. Pengaruh kerapatan mangrove dan kelimpahan Kepiting Bakau diperoleh persamaan regresi yaitu Y = 43,521 +  0,2061x.  Koefisien korelasi (r) yang diperoleh 0,79 yang artinya hubungan kerapatan mangrove dan kelimpahan Kepiting Bakau tergolong kuat yaitu sebesar 79%. Kerapatan mangrove sebanyak 1000 satuan akan meningkatkan kelimpahan Kepiting Bakau sebesar 43,5 individu.


2021 ◽  
Author(s):  
Kei Suzuki ◽  
Yasumitsu Kuwano ◽  
Yuki Kanamori ◽  
Yohei Kawauchi ◽  
Yoshihiko Uchimura ◽  
...  

Regional management of large herbivore populations is known to be effective in reducing local economic damages and conserving local endemic plants. However, herbivores often move across management areas, and the effect of population management on a large spatial scale is poorly understood, even though it is necessary to use a large-scale approach across multiple management units to implement appropriate management. In this study, to better understand large-scale management and improve management efficiency, we evaluated effects of large-scale management of a sika deer (Cervus nippon) population on Kyushu Island (approximately 36,750 km2) in Japan. We estimated the population dynamics and spatial distributions of the deer and evaluated the effects of harvests, density dependence, and climatic conditions on the population dynamics both across Kyushu Island and in smaller prefectural management units. Fecal pellet count surveys conducted from 1995 to 2019 and results from a vector autoregressive spatio-temporal model showed relatively stable population dynamics and four high-density core areas. No increasing or decreasing trends were observed in the population dynamics, even though harvesting increased annually until it reached about 110,000 in 2014, indicating that harvesting was not related to the population dynamics. In addition, although no effects of density dependence were confirmed, maximum snow depth during winter decreased deer density at the management unit scale. Harvesting represents a major source of mortality in the Kyushu Island population because of the absence of predators. Although, approximately 110,000 sika deer were harvested annually after 2014, it is surprising that the effect of harvesting on population dynamics was not significant. A main cause of no reduction of the population was that the population used to determine the harvest number was underestimated. In addition, it was indicated that multi-management units need to manage the core areas because the high-density core areas were located across a few management units. This study highlights the difficulties involved with wide-area management of large herbivores and points out the importance of accurate stock assessment, reduction of the risk of management failure, and cooperation among management units. Our research is an important contribution to the study of the effects of large-scale harvesting in a large geographic area.


Author(s):  
Mariela Veronica Lacoretz ◽  
Daniela María Depalma ◽  
Sebastián A Torrella ◽  
Cecilia Zilli ◽  
Valentina Ferretti ◽  
...  

Worldwide, the areas covered by native forests are declining while those of tree plantations are increasing. This has raised the question of whether tree plantations are able to preserve native forest species. In Argentina, the main native forests of the Pampas region, called talares, are endangered and their disappearance is imminent. Although exotic tree plantations are increasing in this region, their role in maintaining native bird diversity has not been studied in Argentine Pampas. We compared the bird community attributes and vegetation structure of talares native forest with those of tree plantations. Plantations exhibited markedly lower bird richness than talares, up to 80% lower, and all forest-dependent bird species were absent in plantations. Talares and plantations differed also in some aspects of vegetation structure, which usually are key determinants of bird abundance. Given the extreme importance of talares for forest birds, this bird community will be deeply affected if it continues to decline, as nearby plantations do not offer suitable habitat. In order to maintain the bird diversity of talares, and probably the diversity of other unstudied taxa related to them, we recommend management actions that should be applied urgently in these endangered forests of the Argentine Pampas.


2013 ◽  
Vol 23 (4) ◽  
pp. 454-462 ◽  
Author(s):  
LAINIE ZARONES ◽  
MELANIE R. COLÓN ◽  
JAMES C. HA ◽  
RENEE R. HA

SummaryThe Rota White-eye, Zosterops rotensis, is a critically endangered species endemic to the island of Rota, in the Mariana Islands, western Micronesia. There has been a dramatic decline in both its population size and range over the past few decades. The population, estimated at approximately 1,000 individuals in 1999, is found exclusively in 300 ha of mature limestone forest, though nearby areas of mature limestone forest remain unoccupied. We compared the bird community, vegetation characteristics and foliage-invertebrate density in forest plot pairs with known high and low densities of Rota White-eyes. Discriminant function analysis suggested that certain vegetation characteristics were best at predicting whether a plot was high-density or low-density. High-density plots had more stems with 20–50 cm DBH, more foliage intercepts at 3–9 m, more epiphytes, greater total canopy cover and fewer overall plant species. This information is essential for the protection of the current habitat of the Rota White-eye and for future efforts in the protection and management of this species.


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