| In the research, based on the disciplinary theory of ecohydrology and environmental ecology in the urban forest location research station of Pearl River Delta, adopting the location research methods of forest hydrology and the technique of constrasting analyses, hydrological amount and chemical concentration in rainfall, throughfall, surface runoff and catchments runoff were contrasted to measure under rainstorm conditions in Conifer and broadleaf mixed forest and evergreen broadleaf forest in Maofeng mountain of Guangzhou, the hydrological responses, the material recycling and the water balance of forest ecosystems had clarified detailedly, it also provided detailed data of water quality for the area of Malfeng mountain. The results were as follow.(1)Urban forest ecosysterm had many functions of ecosysterm services. Urban forests played an important role in cleaning air, noise reduction and removing dust, water conservation and mitigating urban heat island. Storm rainfall in urban and forest areas were no significant difference on 30 km horizontal scale. Urban destricts’ storm rainfall was 568.8mm, which accounted for 30.9% of annual rainfall. 1561.4mm of rainy season(4-9) accounted for 84.9% of annual rainfall. Forest zone’s storm rainfall was 655.0mm, which accounted for 34.8% of annual rainfall. Rainfall in raimy season from april to september was 1580.4mm, and accounted for 84.0% of annual rainfall.(2)Forest types, forest conapy density, plant organs and so on were key factors of forest conapy interception. Conapy interception rate increased with increasing rainfall, Conapy interception rate tended to steady when holding water capacity of forest conapy reached saturation. The relation between throuthfall and storm rainfall in forest were exponentialrelated, and the fitting equation was that: T1=0.586P1.097, R2=0.998, the fitting equation of evergreen broadleaf forest was that: T2=0.437P1.148, R2=0.985. Mean of conapy interception rate in Conifer and broadleaf mixed forest was 8.2%, conapy interception rate decreased from 12.6% to 5.3%; Mean of conapy interception rate in evergreen broadleaf forest was 14.5%, conapy interception rate decreased from 23.2% to 8.9%, two of them were significant difference(p<0.05).(3)Forest ecosysterms were good for ecological functions of water conservation. Rainfall which passed the layers of arbor, bush, herbaceous, litter, soil and rock had intercepted, it reduced effectively the output of runoff, extended the timing of rainfall-runoff and lagged the rainfall of runoff, all of them reflected ecological function of water conservation, monthly water allocation and water balance. Runoff of 9 rainstorm events in Conifer and broadleaf mixed forest catchments was 124.9mm, mean of runoff rate was 19.1%; Runoff of 9 rainstorm events in evergreen broadleaf forest catchments was 138.6mm, mean of runoff rate was 21.2%, two of them were no significant difference. Annual runoff in Conifer and broadleaf mixed forest catchments was 714.8mm, annual runoff rate was 38.0%; Annual runoff in evergreen broadleaf forest catchments was 802.0mm, annual runoff rate was 42.6%, two of them were no significant difference. Runoff of rainy season(4-9) in Conifer and broadleaf mixed forest catchments was 701.3mm, runoff rate was 44.4%, runoff of rainy season(4-9) was 98.1% of the annual runoff; Runoff of rainy season(4-9) in evergreen broadleaf forest catchments was 704.8mm, runoff rate was 44.6%, runoff of rainy season(4-9) was 87.9% of the annual runoff, two of them were no significant difference. July’s runoff rate in two types of forest catchments was highest in rainy season, July’s runoff in Conifer and broadleaf mixed forest catchments was 62.0mm, runoff rate was 65.7%, July’s runoff in evergreen broadleaf forest catchments was 76.9mm, runoff rate was 81.5%. They were no significant difference.(4)Rainweter chemical concentrations of Urban district and forest zone were no significant difference on 30 km horizontal scale in the rainstorm condition. Mean p H value of 9 rainstorm in forest zone was 5.7, in forest zone was 5.8, chemical concentrations of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in urban district were 1.19, 1.22, 1.37, 1.44, 0.66, 1.53, 0.69, 2.22, 1.14 times than that in forest zone.(5)Chemical concentrations of throughfall in Conifer and broadleaf mixed forest and throughfall in evergreen broadleaf forest were no significant difference in the rainstorm condition. Throughfall chemical concentrations of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in Conifer and broadleaf mixed forest were 0.70, 0.70, 1.07, 1.07, 0.95, 0.80, 0.57, 1.50, 0.88 times to evergreen broadleaf forest. In throughfall of Conifer and broadleaf mixed forest, the order of mean concentrations was that: C> TOC > K+ >S>N> NH4+-N> Ca2+> Mg2+>P, in throughfall of evergreen broadleaf forest, the order of mean concentrations was that: C>TOC> K+ >S>N> NH4+-N> Ca2+> Mg2+>P. According to the net leaching coefficient, leaching coefficient of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in Conifer and broadleaf mixed forest was positive, the order of leaching coefficient was that: K+> Mg2+> Ca2+> S > C > NH4+-N > P > N. In evergreen broadleaf forest, leaching coefficient of them was positive, the order of leaching coefficient was that: K+> Mg2+> S > C > Ca2+> P >NH4+-N > N.(6)Chemical concentrations of slope runoff in Conifer and broadleaf mixed forest and in evergreen broadleaf forest were no significant difference in the rainstorm condition. Slope runoff chemical concentrations of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in Conifer and broadleaf mixed forest were 0.86, 0.85, 0.81, 0.72, 1.11, 0.80, 0.91, 1.24, 1.18 times to evergreen broadleaf forest. The order of mean concentrations in Conifer and broadleaf mixed forest was that: C>TOC > Ca2+> K+ >N> NH4+-N >S > Mg2+>P, in evergreen broadleaf forest was that: C>TOC > Ca2+> K+ >N> NH4+-N >S > Mg2+>P.(7)Total-runoff chemical concentrations of C, N, Ca2+ in two types of forest were significant difference(p<0.05). the mean concentrations of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in Conifer and broadleaf mixed forest were 0.64, 0.63, 1.37, 1.50, 1.28, 0.73, 0.93, 1.14, 1.05 times to evergreen broadleaf forest. In the total-runoff of Conifer and broadleaf mixed forest catchments, the ordre of mean concentrations was that: Ca2+> N> C> K+> S> Mg2+> TOC> NH4+-N> P, in evergreen broadleaf forest catchments, the ordre of mean concentrations was that: Ca2+> N>C> K+ > S > Mg2+> TOC> NH4+-N > P. The migration coefficient of N, S, K+, Ca2+, Mg2+ in two types of forest was positive, the migration coefficient of C, NH4+-N, P in two types of forest was negative.(8)In evergreen broadleaf forest, the mean concentrations of p H, S, NH4+-N in the penetration-water of 30 cm soil depth and 70 cm soil depth were significant difference(p<0.05). The mean concentrations of C, TOC, N, NH4+-N, P, S, K+, Ca2+, Mg2+ in the penetration-water of 30 cm soil depth were 0.99, 0.86, 1.38, 3.99, 1.39, 0.45, 0.91, 1.01, 0.81 times to 70 cm soil depth. In the penetration-water of 30 cm soil depth, the order of mean concentrations was that: C> TOC> S> Ca2+> K+> N> NH4+-N> Mg2+> P. In the penetration-water of 70 cm soil depth, the order of mean concentrations was that: S> C> TOC> K+> Ca2+> N> Mg2+> NH4+-N> P.(9)In evergreen broadleaf forest, the flux of C, N, P, S which total content of total-runoff minus total content of rainfall was negative. It showed that evergreen broadleaf forest ecosysterm had water chemical storage effect to this chemical composition. The storage capacity of C, N, P and S was 24.2%, 64.6%, 11.6% and 54.8% of rainfall input capacity. Totalrunoff output capacity of K, Ca and Mg showed outflow effect, the flux of output capacity was 84.5%, 42.5% and 30.2% of total-runoff output capacity. |
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