Department of Geography

Corn is one of most important agricultural products in China. Understanding impacts of regional climate change, as well as agricultural management practices, on corn yields is critical for maintaining stable corn production. Using the DayCent model and observed climatic data in Sichuan province (a humid and hot environment) and Hebei province (a cold and dry environment) in China, corn yields in 1948-2010 were simulated. The spatial variations of simulated corn yields and the relationship between regional climate variability and warming with corn yields in these two environments were analyzed. The results demonstrated that: (1) corn yields in Zhangjiakou of Hebei and most regions of Sichuan decreased significantly after 2000 compared to other regions; (2) relative humidity and precipitation exhibit a significant negative correlation with observed crop yields in the growing season in Hebei province; (3) air temperature from 23.33 °C to 29 °C constitutes the ideal range influencing the increase of corn yields in Sichuan; (4) the planting of the large amount of silage maize in Sichuan compensated the negative impact of the rising air temperature on corn yields; (5) sensitivity tests for different fertilization levels and OMAD suggest that an increasing fertilization level significantly affects corn yields in Hebei province, a cold and dry environment, while a decreasing fertilization level has a significant negative effect in Sichuan province, a hot and humid environment. The overarching goal of these analyses is to provide the theoretical basic for maintaining stable corn production under regional climate warming and different agricultural management practices.

We report the findings of the first survey for Eurasian otter (Lutra lutra) from the Upper Indus River and several of its tributaries in Leh and Kargil Districts, India. The survey was conducted between 25th August to 30th October, 2015. We report the distribution of otter sign, including camera trap images, scats, tracks, and latrines, and the habitat characteristics along 50 km of riverbank. We observed indirect sign of otter presence on two of the four rivers surveyed, but otter abundance appears to be low in the area. Human disturbance, including proximity to settlements, grazing livestock, and particularly feral dogs, appears to deter otter presence.

This study is an analysis of records of the seizure of otters by law enforcement agencies in selected Asian countries between 1980 and July 2015. The study was undertaken to understand the extent and scale of the illegal otter trade in Asia, and focussed on four Asian otter species i.e., the eurasian otter (Lutra lutra), hairy-nosed otter (Lutra sumatrana), small-clawed otter (Aonyx cinereus), and the smooth-coated otter (Lutrogale perspicillata). All four species were documented in illegal trade, with 161 recorded otter seizures across 15 countries in Asia between 1980 and 2015, involving an estimated 5881 individuals. Otter skins constituted the majority of the seizures, particularly in India, Nepal and China. Since early 2000s, there seems to be a rising demand for otter pups for the pet trade, particularly in Indonesia, Malaysia, Thailand and Viet Nam. While seizure records as a whole were scarce across the region, we conclude that illegal otter trade is persistent and largely unchecked, despite otter species being legally protected across their range.

Abstract: We report the findings of a survey for otters along a major river in central Bhutan. The river bears various names in different stretches along its run, including Mochhu, Phochhu, Punatsangchhu and Sunkosh. We report: 1) the distribution and density of otter sign, including tracks, scats, latrines and dens, 2) the correlation between sign abundance and vegetation and substrate characteristics, and 3) the correlation of otter sign with human disturbance. Five of the six 5.5 km transects sampled were positive for otter sign. The one transect with no otter sign was the site of a recent severe flood event. Linear sign density was 9.4 sign km-1 along one bank of the river, with a mean of 45% of two sample rounds positive for presence of otter sign in sample plots. The Kamichhu site possessed the highest percentage of positive plots at 95%, and the Sunkosh site the lowest at 35%. The number of otter sign was positively correlated with bankside vegetation and with sandy beaches with large boulders. Human disturbance also influenced the density of otter sign, with proximity of settlements, represented by the presence of footpaths, grazing and trash, apparently deterring otter presence. Three species of otters likely occupy the rivers of Bhutan (Lutrogale perspillata, Lutra lutra, and Aonyx cinereus) but since altitudinal niche partitioning by these species is not understood in the study area, we make no attempt to predict distribution by species. Only one otter species, a smooth-coated otter (L. perspicillata) was directly sighted.

A survey for otters across Mongolia was conducted in 2012 to document the status and distribution range of the Eurasian otter (Lutra lutra Linnaeus, 1758), and to propose the scientific basis for government policies to protect the species. We report results from the first survey of otter since the late 1980s (Stubbe et al., 1989), with new records emerged after 2012. The species is very rarely reported in the country, but in addition to an actual sighting of this species, the survey team observed a limited number of otter sign, including tracks, scat, ice diving holes, snow diving marks, snow wallows, territorial marks, and prey remains at widely distributed sites. We recommend a set of strategies to expand conservation for the Eurasian otter in Mongolia.