(Reuters) - As spring warms the sands of the Gobi desert in China's vast Inner Mongolia region, it's not just the local camels who are happy to see the end of a long, cold winter. Just a few hundred meters from towering sand dunes, workers unearth row upon row of grapevines buried under the sand to protect them from temperatures as low as -20 degrees Celsius (-4 Fahrenheit). These vines are helping fuel a booming Chinese wine industry that has grown by leaps and bounds in recent years, as the world's most populous nation grows wealthier and embraces foreign tastes.