## 3 Results
### FRP Estimates Based on Different Sampling Intervals and Calculation Methods  
FRP estimates significantly varied with sampling timing and between the two methods (Figure 4). FRP between T1 and T2 (1338.2 \(\pm\) 243.3 g m\({}^{-2}\) year\({}^{-1}\)) was significantly higher than that at all other sampling periods. FRP between T2 and T3, T2 and T4, T1 and T3 and T1 and T4 (218.1 \(\pm\) 61.9, 349.1 \(\pm\) 39.4, 502.7 \(\pm\) 52.8, 551.4 \(\pm\) 71.8 g m\({}^{-2}\) year\({}^{-1}\), respectively) was comparable to that between T3 and T4. In the simple method, FRP at T0\(-\)T1 (3-months) and T0\(-\)T2 (6-months) (915.2 \(\pm\) 71.1, 1095.0 \(\pm\) 178.2 g m\({}^{-2}\) year\({}^{-1}\), respectively) was significantly higher than that at T0\(-\)T3 and T0\(-\)T4 (516.3 \(\pm\) 45.0, 426.4 \(\pm\) 47.9 g m\({}^{-2}\) year\({}^{-1}\), respectively).  
\(\Delta\)B\({}_{\rm fr}\) and \(\Delta\)N in both methods also differed considerably with sampling timing (Figure 4). \(\Delta\)B\({}_{\rm fr}\) between T1 and T2 was significantly higher, while \(\Delta\)B\({}_{\rm fr}\) between T2 and T3 was lower, than the values obtained for other periods. \(\Delta\)B\({}_{\rm fr}\) at T0-T2 was significantly higher than that during other sampling period in the simple method. \(\Delta\)N between T1 and T2 for the differential method was significantly higher than that during other periods. Similarly, \(\Delta\)N at T0\(-\)T1 and T0\(-\)T2 for the simple method was significantly higher than that during the other periods.  
\(d\) did not differ among the sampling times in either method (Figure 4). However, the contribution of \(d\) to FRP was considerably different among the sampling times in the differential methods (Figure 5). The ratio ranged from 8.2% at T1-T2 to 80.8% at T2\(-\)T3, with the average of 33.4% for the differential method. The contribution of \(d\) to FRP in the simple method increased with increasing sampling interval. The ratio was only 7.2 and 9.0% at T0-T1 and T0-T2, respectively but increased to 14.7 and 19.4% at T0-T3 and T0-T4, respectively.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline  & **NPP\({}_{\rm fr}\)** & **NPP\({}_{\rm acw}\)** & **NPP\({}_{\rm litterfall}\)** & **NPP\({}_{\rm total}\)** & **NPP\({}_{\rm fr}\)/NPP\({}_{\rm total}\)** & **Reference** \\ \hline Malaysia, Lambir & 4.25 \(\pm\) 0.84 & 3.74 \(\pm\) 0.29 & 3.02 \(\pm\) 0.36 & 11.01 \(\pm\) 0.96 & 0.39 & This study, [19] \\ Malaysia, Lambir & 1.96–1.96 & 2.87–4.17 & 5.99–7.89 & 10.82 & 0.18 & [5] \\ Brazil, Casuiana & 3.89 \(\pm\) 0.80 & 2.55 \(\pm\) 0.06 & 2.94 \(\pm\) 0.04 & 9.38 \(\pm\) 0.80 & 0.41 & [28] \\ Brazil, Casx06 & 3.68 \(\pm\) 0.52 & 3.02 \(\pm\) 0.30 & 5.03 \(\pm\) 0.07 & 11.73 \(\pm\) 0.60 & 0.31 & [29] \\ Bolivia, KEN01 & 4.03 \(\pm\) 0.47 & 5.27 \(\pm\) 0.31 & 6.20 \(\pm\) 1.09 & 15.5 \(\pm\) 1.23 & 0.26 & [30] \\ KEN02 & 3.04 \(\pm\) 0.34 & 3.61 \(\pm\) 0.23 & 4.62 \(\pm\) 0.90 & 11.27 \(\pm\) 0.99 & 0.27 & \\ Peru, TAM05 & 4.54 \(\pm\) 0.71 & 2.41 \(\pm\) 0.24 & 5.39 \(\pm\) 0.35 & 12.34 \(\pm\) 0.83 & 0.37 & [31] \\ TAM06 & 2.11 \(\pm\) 0.31 & 2.49 \(\pm\) 0.25 & 4.94 \(\pm\) 0.40 & 9.54 \(\pm\) 0.56 & 0.22 & \\ ALP01 & 3.02 \(\pm\) 0.29 & 2.54 \(\pm\) 0.25 & 4.70 \(\pm\) 0.86 & 10.26 \(\pm\) 0.94 & 0.37 & [32] \\ ALP30 & 3.50 \(\pm\) 0.38 & 2.  
Figure 3: Ratio of fine root biomass to fine root necromass inside the cores at T1 to T4. Standard errors are indicated (\(n=3\)). Dashed line indicates the ratio of fine to dead root biomass outside the cores (3.47 \(\pm\) 0.42).  
Figure 2: Temporal variation in (**a**) fine root biomass and (**b**) fine root necromass inside the cores between sampling time T1 and T4. Different letters indicate significant differences among the sampling times (\(p<0.05\)). Standard errors are indicated (\(n=3\)). Dashed lines indicate fine and dead root biomass outside the cores (968.7 \(\pm\) 32.9, 288.8 \(\pm\) 40.0 g m\({}^{-2}\), respectively).