Top 10 countries in plant and animal sciences based on citations per paper

	Country	Papers	Citations	Citations per paper
1	England	31,950	375,517	11.75
2	Wales	2,568	28,376	11.05
3	Scotland	10,496	110,902	10.57
4	The Netherlands	12,940	135,483	10.47
5	Sweden	9,907	103,057	10.40
6	Switzerland	8,821	90,430	10.25
7	Denmark	7,594	75,045	9.88
8	Israel	5,353	52,750	9.85
9	US	158,020	1,469,201	9.30
10	France	,877	254,780	9.14

The data above were extracted from the Essential Science Indicators database of Thomson Reuters. This database, currently covering the period January 1998 through December 2008, surveys only journal articles (original research reports and review articles) indexed by Thomson Reuters. Articles are assigned to a category based on the journals in which they were published and Thomson Reuters’ journal-to-category field-definition scheme. Both articles tabulated and citation counts to those articles are for the period indicated. Here our ranking in plant and animal sciences is by citations per paper – among nations that earned 25,000 or more citations during the period – to reveal weighted impact. For articles with multiple authors from different nations, each nation receives full, not fractional, citation credit. Essential Science Indicators lists nations ranked in the top 50 per cent for a field over a given period, based on total citations. In plant and animal sciences, 106 nations are listed, meaning 212 were surveyed. Thirty-two nations collected at least 25,000 citations during the period. For more information on Thomson Reuters’ Essential Science Indicators, see http://scientific.thomsonreuters.com/products/esi.