Table 2.

Estimates and 95% confidence limits for total species number with k as a linear function of N_t−1. (Only British flora and birds of the world are shown, as the other groups showed no decline in S_t.)

data range	date range	N	dispersion	estimate	95% CI
British floraa
0.6–1.0	1754–2004	552	n.a.	n.a.	n.a.
0.9–1.0	1828–2006	144	3.1	1502	1459–2222
0.6–0.9	1754–1827	408	4.2	1526	1343–2178
0.6–0.8	1754–1796	264	n.a.	n.a.	n.a.
0.91–1.0	1835–2006	131	3.2	1493	1459–1558
birds
0.0–1.0	1758–2004	9961	47.9	10 024	9957–n.a.
0.6–1.0	1856–2004	3979	n.a.	n.a.	n.a.
0.8–1.0	1883–2004	1974	2.4	10 118	10 032–19 988
0.6–0.9	1856–1904	3003	5.6	10 316	9605–15 734
0.83–1.0	1889–2004	1665	2.3	10 298	10 067–13 115

^aData for British flora omit Linnaeus' 1753 descriptions which contain 907 species.