Abstract. The soils underlying the 12 Fire and Fire Surrogates Network include six soil orders and .50 named soil series. Across the network, pretreatment soils varied from 3.7 to 7.1 in pH, and exhibited ranges of twofold in bulk density, fourfold in soil organic C (SOC) content, 10-fold in total inorganic N (TIN), and 200-1000-fold in extractable Ca and K. Nonmetric multidimensional (NMS) ordination of pretreatment soil conditions arrayed the FFS sites along gradients of pH/base cation status, net N transformation rates, bulk density, and SOC. At the network scale, mineral soil exposure was significantly greater in fire-only (mean of 9.2%) and mechanical þ fire (5.0%) treatments than in the controls (1.5%) during the first posttreatment year, and this persisted through the later sampling year (second through fourth year, depending on site) in the fire-only treatment (fire 4.1%, control 1.1%). Bulk density was not affected significantly at the network scale. TIN concentrations during the first posttreatment year increased after all three manipulative treatments, but this effect did not persist to the later sampling year. Neither SOC content nor soil C:N ratio was affected by any of the treatments at the network scale. At the individual site scale, the combined mechanical þ fire treatment produced more significant site 3 treatment 3 year effects than did the fire-only or mechanical-only treatments, though in most cases even the statistically significant differences produced by the manipulative treatments were modest in magnitude. Ordination of first-year standardized effect sizes produced no discernable separation of the three manipulative treatments but did separate the three sites with the greatest fire severity (based on proportional fuel consumption) from the majority of the network sites, with changes in pH, TIN, SOC content, and soil C:N ratio correlating most strongly with this separation. Ordination of the effect sizes from the later sampling year produced somewhat clearer separation of treatments than did the first-year ordination, though fewer sites were represented in this second ordination. Overall, the network-wide effects of the FFS treatments on soil properties appear to have been modest and transient.

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In evergreen broad-leaved forests (EBLFs) in Tiantong National Forest Park, Eastern China, we studied the soil chemistry and plant leaf nutrient concentration along a chronosequence of secondary forest succession. Soil total N, P and leaf N, P concentration of the most abundant plant species increased with forest succession. We further examined leaf lifespan, leaf nutrient characteristics and root-shoot attributes of Pinus massoniana Lamb, the earlysuccessional species, Schima superba Gardn. et Champ, the mid-successional species, and Castanopsis fargesii Franch, the late-successional species. These species showed both intraspecific and interspecific variability along succession. Leaf N concentration of the three dominant species increased while N resorption tended to decrease with succession; leaf P and P resorption didn't show a consistent trend along forest succession. Compared with the other two species, C. fargesii had the shortest leaf lifespan, largest decay rate and the highest taproot diameter to shoot base diameter ratio while P. massoniana had the highest root-shoot biomass ratio and taproot length to shoot height ratio. Overall, P. massoniana used 'conservative consumption' nutrient use strategy in the infertile soil conditions while C. fargesii took up nutrients in the way of 'resource spending' when nutrient supply increased. The attributes of S. superba were intermediate between the other two species, which may contribute to its coexistence with other species in a wide range of soil conditions.

We examined soil nitrogen (N) mineralization and nitriWcation rates, and soil and forest Xoor properties in one native forest: evergreen broad-leaved forest (EBLF), one secondary shrubs (SS), and three adjacent plantation forests: Chinese Wr plantation (CFP), bamboo plantation (BP) and waxberry groves (WG) in Tiantong National Forest Park, Eastern China. All forests showed seasonal dynamics of N mineralization and nitriWcation rates. Soil N mineralization rate was highest in EBLF (1.6 § 0.3 mg-N kg ¡1 yr ¡1 ) and lowest in CFP (0.4 § 0.1 mg-N kg ¡1 yr ¡1 ). Soil nitriWcation rate was also highest in EBLF (0.6 § 0.1 mg-N kg ¡1 yr ¡1 ), but lowest in SS (0.02 § 0.01 mg-N kg ¡1 yr ¡1 ). During forest conversion of EBLF to SS, CFP, BP and WG, soil N mineralization rate (10.7%, 73%, 40.3% and 69.8%, respectively), soil nitriWcation rate (94.9%, 32.2%, 33.9% and 39%, respectively), and soil N concentration (50%, 65.4%, 78.9% and 51.9%, respectively) declined signiWcantly. Annual soil N mineralization was positively correlated with total C and N concentrations of surface soil and total N concentration of forest Xoor, and negatively correlated with soil bulk density, soil pH and C:N ratio of forest Xoor across the Wve forests. Annual soil nitriWcation was positively correlated with total C concentration of surface soil and N concentration of forest Xoor, and negatively correlated with soil bulk density and forest Xoor mass. In contrast, annual soil nitriWcation was not correlated to pH value, total N concentration, C:N ratio of surface soil and total C concentration and C:N ratio of forest Xoor.