{'fraction_non_alphanumeric': 0.03969754253308128, 'fraction_numerical': 0.02551984877126654, 'mean_word_length': 6.06, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effects of Simulated Nitrogen Deposition on Litterfall Nitrogen Concentrations and Its Annual Flux in Chinese fir Plantations

A simulated nitrogen deposition experiment was conducted in Chinese fir plantations in the subtropical region in China.Treatments were designed as N0(0 kg/hm2·a N),N1(60 kg/hm2·a N),N2(120 kg/hm2·a N) and N3(240 kg/hm2·a N),with three replicates in each treatment.Based on two years of litterfall measurements,nitrogen deposition was found to significantly elevate nitrogen concentrations in fallen leaves,but nitrogen concentrations in other litterfall components(branches,fruits,barks and other droppings) displayed insensitive response to N deposition,no difference existed between the treatments.The annual nitrogen flux in litterfall responded positively to all N treatments,it had an increase of 32.6% in N3,10.9% in N2,but no significant gain in N1,compared with the control(N0).Seasonal dynamics of nitrogen flux in litterfall was different among the treatments,but generally showed two peaks occurring in February and May.