Boreal trees in the Mediterranean: recruitment of downy birch (Betula alba) at its southern range limit

Table 2 Descriptive statistics of seed density and exponential negative curve fits (y = a × e^(−bx)) of distance–seed density relationships for the different populations and years

Population	Year	Mean seed density (seed/m²)	a	b	SE	r
Honduras	2005	3471 ± 796	26,345.51	0.17	811.55	0.994
Nogaledas	2005	1369 ± 374	13,231.16	0.19	362.07	0.995
Casas del Monte	2005	2926 ± 750	31,367.35	0.22	308.61	0.999
Honduras	2006	1689 ± 510	17,229.72	0.32	107.01	0.999
Nogaledas	2006	434 ± 102	4,844.55	0.22	30.57	0.999
Casas del Monte	2006	740 ± 171	8,612.90	0.27	62.74	0.999

ISSN: 1297-966X