Mineralization and nitrification in three Malaysian forest soils

Chandler, Graeme

doi:10.1016/0038-0717(85)90072-0

Cited by 29 publications

(13 citation statements)

References 31 publications

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“…Mean rates of N net mineralization as obtained from 8-d in situ-incubations were close to values reported from other tropical forests on moderately fertile soils (1-3 μgN g −1 d −1 ), while lower mineralization rates were observed in forests on oxisols, ultisols or other less fertile substrates, and also in some montane Lamb 1980;Robertson 1984;Chandler 1985;Vitousek and Denslow 1986;Vitousek and Sanford 1986;Matson et al 1987;Marss et al 1988;Montagnini and Buschbauer 1989). That the mineralization rates in East Ecuador were relatively high at montane elevation may be explained by the rather low C/N ratios along this transect.…”

Section: Elevational Change In N Availabilitysupporting

confidence: 83%

Variability of indices of macronutrient availability in soils at different spatial scales along an elevation transect in tropical moist forests (NE Ecuador)

2010

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The availability of key plant nutrients may change with elevation in tropical mountains due to altitudinal gradients in temperature and moisture which affect pedogenesis and nutrient cycling. In a transect from upper lowland to montane forests in NE Ecuador, we tested the hypotheses that (1) the availability of P is low in low-elevation forests but increases upslope, while the availability of N is relatively high at low elevations but decreases with elevation, and (2) increasing amounts of calcium, magnesium and potassium are stored on top of the soil with progressive humus accumulation toward higher elevations, likely to improve nutrient availability. In each 20 plots in undisturbed natural forest at 500, 1000, 1500 and 2000 ma.s.l., we measured in situ N net mineralization and nitrification rate (N NM and N NI , buried bag method), plant-available phosphorus (P a , resin-bag method), and salt-exchangeable calcium, potassium and magnesium concentrations (Ca ex , K ex , Mg ex ) in the organic and mineral topsoils. N NM and N NI , and the Ca ex , K ex and Mg ex concentrations were much more variable at the plot level than across the four elevations, while P a varied equally at small and large spatial scales. P a increased more than 10fold from 500 to 2000 m. The net release of nitrate dominated over ammonium at all elevations. While mass-related N NM and N NI rates and also organic matter C/N ratio in the topsoil remained invariant along the slope, N NM and N NI rates per ground area decreased by about 40% from 500 to 2000 m. Thus, the N NM /P a ratio decreased markedly with elevation proving our first hypothesis. In support of the second hypothesis, the pools of Ca ex , Mg ex and K ex in the organic layers increased with elevation, demonstrating the key role that organic topsoil horizons are playing for forest nutrition at high elevations. We suggest that the large difference in N versus P availability of tropical (upper) lowland and montane forests is likely to be a key factor influencing the species composition and productivity along tropical mountain slopes.

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Section: Elevational Change In N Availabilitysupporting

confidence: 83%

Variability of indices of macronutrient availability in soils at different spatial scales along an elevation transect in tropical moist forests (NE Ecuador)

2010

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“…But, the rates of the net N mineralization and net nitrification observed in our forest soils were well within the range reported in other tropical forests (Livingston et al 1988; Montagnini and Buschbacher 1989;Garcia-Mendez et al 1991). The net nitrification rate in our forest soils, however, was lower than the tropical forest of Amazon Basin, Brazil (1.32 µg g −1 day −1 to 3.51 µg g −1 day −1 ) (Neill et al 1997), but higher than Malaysian forest (0.04 µg g −1 day −1 to 0.75 µg g −1 day −1 ) (Chandler 1985).…”

Section: Net N Mineralization and Net Nitrification In Native Forestcontrasting

confidence: 45%

Soil nitrogen and microbial biomass carbon dynamics in native forests and derived agricultural land uses in a humid tropical climate of India

Pandey

Singh

et al. 2010

Plant Soil

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Conversion of tropical forests to agricultural land uses is known to alter soil nitrogen (N) transformation processes and microbial biomass carbon (MB-C ), which affect productivity and stability of the derived land uses. Information about how conversion of moist evergreen forest to agricultural land uses affects soil nitrogen (N) transformation processes and MB-C in hot humid tropics is meager. The present study explores the following questions: (1) how does conversion of native moist evergreen forest to agricultural production systems (grassland, home garden and silvopasture) affect net soil N mineralization rates, pools of mineral nitrogen (NH 4 + -N and NO 3 --N) and MB-C in the hot humid tropical climate of South Andaman, India and (2) are changes in soil N transformations and MB-C related to differences in soil moisture and temperature induced with forest conversion? Variations in net soil N mineralization, NH 4 + -N and NO 3 − -N pools, MB-C and soil temperature and moisture were measured across wet, postwet and dry seasons at ten sites of each derived agricultural land use and native forest. In addition, inputs of carbon (C ) and N to the soils and outputs of C and N from the land use systems through harvests were also measured. We measured the N mineralization rate by the buried bag technique using 2 M KCl as an extractant. The NO 3 − -N and NH 4 + -N were measured at the beginning and end of incubation. The MB-C was measured by a chloroform fumigation-extraction method. We found that forest conversion resulted in a decline in carbon input, but caused rise in soil temperature (from 0.4 to 9.8% across the seasons) in derived agricultural land uses compared to native forest. The soil temperature increase was the highest in the grassland and lowest in the home garden. Across the three seasons, net soil N mineralization rates increased 27 to 55 % in the derived agricultural land uses compared to the native forest, with the increase highest in the grassland and lowest in the home garden. Soil organic C (SOC), MB-C, and NO 3 -declined in the derived agricultural land uses relative to native forest, with the greatest effect again seen in the grassland. These observations suggest that native forest conversion to agricultural uses results in lower soil organic C content over time, due to increased mineralization rates stimulated by a rise in soil temperature, and that these soil changes may be most pronounced in grasslands. Therefore, tree based land uses offer good options for soil carbon build up and protection against N loss in the hot humid tropics.

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“…In turn, this may provide further circumstantial evidence to support the view that soil chemistry (i.e. nutrient availability and/ or low pH associated effects) is the major deter- Wells 1977Wells 1977Chandler 1985Chandler 1985 mining factor for the distribution of the heath forest formation.…”

Section: Maearanga Heynei Is One Of a Group Of Species That Could Be mentioning

confidence: 77%

Adinandra belukar: an anthropogenic heath forest in Singapore

1992

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Adinandra belukar is a species-poor forest dominated by Adinandra dumosa (Theaceae) found in Singapore and southern Peninsular Malaysia. It is the product of secondary succession after exhaustive agricultural exploitation on land cleared of primary lowland rain forest. A high degree of similarity in vegetation between different sites was found for seven 225 m 2 plots in adinandra belukar in Singapore.Adinandra dumosa was dominant or codominant in all plots, generally found in association with the woody species Dillenia suffruticosa, Fagraea fragrans, and Rhodamnia cinerea, the climber Gynochthodes sublanceolata, the fern Dicranopteris Iinearis and the terrestrial orchid Bromheadia finlaysoniana. All sites had extremely acidic (pH 3.3-3.9) surface (0-20 cm) mineral soils with very low total nitrogen (0.06-0.14~o) and total phosphorus (11-29 #g g -l ) contents and very high carbon/nitrogen ratios (33-48). Adinandra belukar is interpreted as a heath forest because of its floristic and physiognomic similarities with this forest formation.Nomenclature: follows Turner, Chua and Tan (1990), A checklist of the native and naturalized vascular plants of the Republic of Singapore.

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Mineralization and nitrification in three Malaysian forest soils

Cited by 29 publications

References 31 publications

Variability of indices of macronutrient availability in soils at different spatial scales along an elevation transect in tropical moist forests (NE Ecuador)

Variability of indices of macronutrient availability in soils at different spatial scales along an elevation transect in tropical moist forests (NE Ecuador)

Soil nitrogen and microbial biomass carbon dynamics in native forests and derived agricultural land uses in a humid tropical climate of India

Adinandra belukar: an anthropogenic heath forest in Singapore

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