Large-scale forest inventories of the United States and China reveal positive effects of biodiversity on productivity

Forest Ecosystems

Table 5 Parameters of site productivity models by forest type with predictor variables of species richness, basal area, elevation, and slope

Forest type	n	AIC	BIC	Coefficients
Forest type	n	AIC	BIC	Const.		N		N ²		N · B		B
Pinyon/juniper	16,709	47112	47158	−0.398	***	0.209	***	−0.012	***	0.005	***	−0.010	***
Douglas-fir (Coastal)	5,866	29214	29241	−0.024				−0.011	***	0.002	***
Douglas-fir (Interior)	1,211	5259	5284	−2.735	***	0.809	***	−0.035	**			0.031	***
Oak/pine	19,023	86805	86853	−1.599	***	0.205	***	−0.008	***	−0.001	*	0.047	***
Oak/gum/cypress	28,431	128225	128266	−1.058	***	0.142	***			−0.002	***	0.019	***
Elm/ash/cottonwood	11,742	55755	55800	−1.394	***	0.244	***	−0.010	***	−0.003	***	0.048	***
Aspen/birch	46,411	200909	200953	−0.865	***	0.105	***			−0.004	***	0.040	***
Southern pine	102,844	457216	457273	−1.070	***	0.093	***	−0.001	**	−0.001	***	0.040	***
Oak/hickory	141,062	636358	636397	−0.798	***	0.040	***					0.026	***
Maple/beech/birch	47,350	206442	206495	3.703	***	−0.033	*	0.013	***	−0.004	***	0.024	***
Tropical and exotic hardwoods	408	1700	1712	−0.409	**							0.028	***
Northern pines	9,151	40244	40280	−1.469	***	0.161	***			−0.007	***	0.075	***
Spruce/fir and exotic softwoods	18,761	79280	79327	2.011	***	0.479	***	−0.025	***	−0.002	**	0.008	*
Western conifers	21,792	101207	101247	−1.409	***	0.184	***			0.003	***	0.029	***
Western hardwoods	1,924	8041	8075	−0.386	**	0.446	**	−0.125	***	0.010	***	−0.017	*
Western oak	3,207	15060	15090	−1.311	***	0.409	***	−0.037	*	0.015	***
Chinese northeastern temperate forest	1,385	4768	4789	1.288	***	0.397	***	−0.017	***	−0.0007		0.004