Grassland sandy desertification is one of the main reasons that the grassland ecosystem degradation and productivity decline continuously.

草地沙化是引起草地持续退化和生产力不断下降的主要原因之一。

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It is believed that all tree utilization and short rotation system were main factors responsible for nutrient depletion and productivity decline of the stand sites.

“全树利用”及其短轮伐期经营制度是导致林地养分衰竭和生产力下降的主要原因。

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This paper treats of the causes of site productivity decline of artificial forest, including planting methods, climate, soil, population structure, species and the proper measures.

本文从育林措施、气候、土壤、人工林群落结构、树种等方面概述了引起地力衰退的主要因素和应对策略。

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Indeed,volatile food prices, population growth, low agricultural productivity and the potentially devastating effects of climate change make it a particularly daunting challenge. The IFAD president says over the past 30 years, agricultural productivity in developing countries has been stagnant or in decline. He blames it on years of under-investment.

VOA: standard.2010.03.29

But the statistics all show a catastrophic and continuing productivity decline.

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Handal says an employee should always call in sick when the illness is still contagious and his or her productivity will notably decline due to the illness.

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The general rule of thumb is that running backs experience a decline in productivity around the age of 30 due to the wear and tear they undergo.

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