3.2 Reproductive traits changed under the N and P addition treatments
Seed number per inflorescence and inflorescence number were significantly influenced by N addition (both P < 0.001), whereas P addition significantly affected seed number per inflorescence (P < 0.05) but not inflorescence number (P > 0.05; Figure 2, Table 1). The low N addition stimulated seed number per inflorescence by 120%, 145%, and 175% under ambient, low, and high P addition conditions, respectively (allP < 0.05; Figure 2a left insert, Table 1). The high N addition increased seed number per inflorescence by 183%, 187%, and 247% under the ambient, low, and high P addition treatments, respectively (all P < 0.05). Although the low P addition did not affect seed number per inflorescence under ambient, low, or high N addition conditions (all P > 0.05). However, high P addition enhanced seed number per inflorescence by 29% under the low N, and 27% under the high N addition treatments (bothP < 0.05), but not under ambient N (P> 0.05; Figure 2a right insert).
The low N addition increased the inflorescence number by 317%, 513%, and 396% under the ambient, low, and high P addition treatments, respectively (all P < 0.05), but this effect was stronger under high N addition with corresponding increases of 719%, 1187%, and 934% under ambient, low, and high P addition conditions, respectively (all P < 0.05; Figure 2b left insert). However, either a low or high P addition did not influence inflorescence number under the ambient or low N addition treatments (all P> 0.05; Figure 2b right insert). Yet the low P addition was able to significantly augment inflorescence number by 49% under the high N addition treatment (Figure 2b right insert; P < 0.05).