Small Litterfall Research Articles

Does water stress, nutrient limitation, or H-toxicity explain the differential stature among Heath Forest types in Central Kalimantan, Indonesia?

To investigate the causes of the reduced stature of heath forest compared to lowland evergreen rain forest (LERF), the quantity and quality of small litterfall (LF), the standing crop of litter on the forest floor (LSC), and the annual rates of litter decay were determined over a period of 12 months in three contrasting lowland rain forest types in Central Kalimantan, Indonesia. In addition, a litterbag experiment monitored the mass loss of leaves from three dominant tree species in two heath forests (HF) of contrasting stature. Soil water and shallow groundwater dynamics in the two HFs were monitored as well. LF in the LERF was higher compared to both tall heath forest (THF) and relatively stunted heath forest (SHF), but did not differ between the two HFs. Stand-level nutrient-use efficiencies for nitrogen and phosphorus were greatest for the SHF, followed by the THF and the LERF, respectively. The observed differences in nutrient-use efficiency between the two HFs did not result in different LF totals, LSC or decomposition rates and hence cannot explain the difference in HF stature. Neither could phenolic concentrations in leaf LF, which were very similar for the two HFs. Top-soil moisture levels were consistently higher in the SHF compared to the THF and never reached wilting point in either forest type whereas shallow groundwater levels in the SHF were both closer to the surface and more persistent than in the THF. Thus, severe water stress is not thought to be a factor of importance determining HF stature. Rather, considering the much lower pH of the topsoil in the SHF compared to the THF it is hypothesized that different degrees of H-toxicity to fine roots may ultimately prove responsible for the contrast in HF stature.

Effects of fragmentation on forest structure and litter dynamics in Atlantic rainforest in Pernambuco, Brazil

This study evaluates the effects of fragmentation on the spatial and temporal dynamics of small litterfall production in Atlantic rainforest in Pernambuco State, Brazil. Litterfall was collected for 24 months at two 0.2 ha sites, located in the forest edge zone and the forest interior, within a rainforest patch of about 300 ha. Structural parameters of both forest sites were recorded. Litter was sorted into six fractions (foliage, twigs, buds/flowers, fruits/seeds, peduncles, rest), dried and weighed. The interior forest plot contained 314 live trees with a dbh ⩾5 cm and a stand basal area of 41.8±8.7 m 2, whereas the forest edge contained 211 live trees and a stand basal area of 23.4±3.6 m 2. Total small litterfall was extraordinarily high and totalled 12.62±4.73 t ha −1 yr −1 in interior forest and 14.74±2.78 t ha −1 yr −1 in forest edge. High litterfall rates are probably due to a pronounced periodicity, edge effects alter litterfall strongly.

Input, accumulation and turnover of organic matter, nitrogen and phosphorus in surface organic layers of an upper montane rainforest in Sri Lanka

Summary Small litterfall was collected monthly for 3 years from traps in an upper montane rainforest at Hakgala in Sri Lanka. The range of mean total litterfall was 6.6–8.7 Mg ha −1 yr −1 of which 77–83% was leaf litter. The inputs of N and P in litterfall were 111.7 and 5.4 kg ha −1 yr −1 , respectively. The mean accumulation of litter on the forest floor was 10.16 Mg ha −1 of which 72% was woody litter. The turnover time of total fine litter was 1.3 years while that of N and P was 1.0 and 0.7 years, respectively, indicating high nutrient circulation. There was low stand use efficiency for N and P (69 and 1437, respectively). Brief comparison is made of the data from this tropical montane forest with other tropical montane forests.

Belowground biomass, production, and carbon cycling in mature Norway spruce, Maine, U.S.A.

Two 55-year-old stands of Norway spruce (Picea abies (L.) Karst.) were sampled to determine belowground biomass, production and decomposition of fine and small roots, litterfall and litter decay rates, soil respiration rates, and carbon cycling patterns. Mean biomass of live fine (<1 mm) Norway spruce roots to a soil depth of 40 cm was 359 ash-free dry g·m–2, whereas biomass of live fine + small roots ([Formula: see text]3 mm) amounted to 561 g·m–2. Mean root production averaged 297 g·m–2·year–1for roots <1 mm and 418 g·m–2·year–1for roots [Formula: see text]3 mm. By comparison, needle litter production was 205 g·m–2·year–1. Norway spruce roots [Formula: see text]3 mm decomposed at a rate of 9.5% of total root mass per month during the growing season, compared with a needle litter annual decay rate of 22.3%·year–1. A partial carbon budget for Norway spruce indicated that annual needle litterfall mass was 98 g C·m–2·year–1, and annual carbon release from fresh litter decay was approximately 22 g·C·m–2·year–1. During the growing season, monthly CO2flux from soil respiration was 69 g C·m–2·month–1, belowground C allocation to net production of roots [Formula: see text]3 mm was 33.5 g C·m–2·month–1, and C release from decomposition of roots [Formula: see text]3 mm was 31 g C·m–2·month–1. These values were also extrapolated to annual estimates of C fluxes.

Biogeochemical consequences of the transformation of native Cerrado into Pinus caribaea plantations in Brazil

Under the same climatic and edaphic conditions, native savanna vegetation in Brazil, the Cerrado, shows a lower stature and canopy cover than planted Pinus caribaea Morelet forests. To assess the differences in biogeochemical element cycling we compared the nutrient economy of Cerrado and Pinus on three replicate plots of each forest type. The mean nutrient storage in the soil organic layer under Pinus (N: 2630; P: 141; K: 103; Ca: 131; Mg: 20 kg ha−1) was substantially higher than under Cerrado (N: 23; P: 1.2; K: 0.83; Ca: 5.8; Mg: 1.0 kg ha−1) probably because the Pinus roots explored a larger soil volume. The Pinus trees had a higher nutrient-use efficiency as indicated by higher mean litter mass per unit nutrient in litter (N: 108; P: 2290; K: 729; Ca: 1360; Mg: 5420; S: 1190; Fe: 2960; Mn: 9990, Zn: 145000) than the Cerrado trees (N: 94; P: 1810; K: 619; Ca: 302; Mg: 938, S: 746; Fe: 1800; Mn: 7880; Zn: 63700). Mean annual small litterfall collected in 0.25-m2 samplers between May 1997 and April 1999 was 2.1 Mg ha−1 in Cerrado and 7.8 in Pinus. The litterfall rates of the 1–3 week collection intervals correlated negatively with the soil matric potential indicating that litterfall was partly related to water stress. The fluxes of N (73 kg ha−1 year−1), P (3.7), K (11), S (7.0), and Mn (0.83) to the soil with litterfall under Pinus were greater than the litterfall+turnover of the grass/herbs layer under Cerrado (N: 39, P: 2.8, K: 8.6, S: 5.4, Mn: 0.79 kg ha−1 year−1), those of Zn (0.06–0.07) were similar, and those of Ca (Pinus: 5.9/Cerrado: 10), Mg (1.5/4.4), and Fe (2.9/4.0) were smaller. Mean residence times of the organic matter and of all elements were longer in the soil organic layer under Pinus (3.7–26 years in the Oi horizon, 8.1–907 years in the whole organic layer) than under Cerrado (0.22–3.6 years in the Oi horizon, the only organic horizon under Cerrado). Our results demonstrate that the main differences in biogeochemical element cycling between the Pinus forest and the Cerrado consisted of a larger nutrient storage in the organic layer, a higher nutrient-use efficiency, and slower nutrient release rates from the organic layer in the Pinus forest than in the Cerrado. Nutrient cycling as assessed by the nutrient fluxes with litterfall was only partly faster in the Pinus forest than in the Cerrado.

Litterfall and nutrient return in seasonally flooded and non-flooded forest of the Pantanal, Mato Grosso, Brazil

Seasonally flooded evergreen forests and non-flooded deciduous and semi-deciduous forests of the Pantanal of Mato Grosso, Brazil, were studied to compare their structure and floristic composition, their production of small litterfall and its seasonal variation, as well as the nutrient input into the soil by fallen litter. The litterfall data were used to test the hypothesis that seasonally flooded forests of the Pantanal are more productive than non-flooded forests. Eight permanent plots of 0.25 ha each were established in three forest types. The clayey forest soils had low N and P concentrations, a CEC from 20 to 190 μmol g −1 and a pH from 5.1 to 6.6. All trees of ≥5 cm DBH were identified and their diameters measured. Tree density and stand basal area ranged, respectively, from 368 to 1700 ha −1 and 15.5 to 25.3 m 2 ha −1 in non-flooded and from 725 to 2005 ha −1 and 22.1 to 32.6 m 2 ha −1 in seasonally flooded forests. There were no significant differences in stem density and basal area between non-flooded and seasonally flooded forest. Species richness ranged from 4 to 17 per plot. Small litterfall (leaves, wood≤2 cm, reproductive parts, trash<2 mm) was collected monthly over three years in 25 litter traps on each plot. Dry weights and element concentrations (N, P, K, Ca, Mg, Al) of litter fractions were determined. Concentrations of P, Ca, and Mg were highest in leaf litter from plots with many deciduous species. Accumulated Al (1.4%) was found in litter from Vochysia divergens Pohl. Element accession rates were low in deciduous and high in semi-deciduous and evergreen forest. Total litterfall in non-flooded deciduous and semi-deciduous forest (4.86 to 7.71 t ha −1 year −1) was significantly lower than in seasonally flooded evergreen forest (7.53 to 10.27 t ha −1 year −1). The findings show that, despite seasonal water excess being the prominent feature of the Pantanal, it is water shortage in the dry season that limits forest productivity.

Structure, composition and small litter dynamics of a semi-deciduous forest in Mato Grosso, Brazil

Structure, floristic composition, and the dynamics of small litterfall and the litter layer were studied for one year in semi-deciduous forest in Mato Grosso, Brazil. This vegetation type is rapidly disappearing as its mesotrophic soils are much in demand for agricultural development. The field site was located at 15°42′S, 56°06′W in the cerrado (savanna) region of the seasonal tropics not far from the southern limit of the Amazonian forest. The 0.25 ha study plot contained 236 trees with a dbh ≥5 cm and a maximum height of over 20 m. Stand basal area was 21.8 ± 2.0 m2 · ha−1. Tabebuia impetiginosa, Dipteryx alata, and Astronium urundeuva were dominant among the 35 recorded tree species from 20 families. Structure and floristics of the study site were similar to semi-deciduous forest found elsewhere in Mato Grosso. Total smalllitterfall was 7.7 ± 0.3 t · ha−1 · year−1. and fell within the range reported for semi-deciduous and deciduous tropical forests. Leaf litter made up over 68% and was five times higher in the dry season than in the wet season. Mean mass of small ground litter was 3.1 ± 0.4 t · ha−1 ranging from 1.6 ± 0.1 t to 6.1 ± 0.2 t · ha−1 for the wet and dry season, respectively. Seasonality of litterfall and decomposition of leaf litter was very high compared with published data.

Ecosystem dynamics at disturbed and undisturbed sites in North Queensland wet tropical rain forest. III. Nutrient returns to the forest floor through litterfall

The nutrient contents and accessions in litterfall over a period of 3 y are reported for undisturbed areas and at two sites disturbed by selective harvesting in tropical rain forest in North Queensland, Australia. Mean concentrations (mg g&amp;supminus1; dry weight) of nutrients in litterfall ranged from 10 to 12 for nitrogen; 0.33 to 0.43 for phosphorus; 3.6 to 4.3 for potassium; 6.0 to 10.5 for calcium; and 1.7 to 2.6 for magnesium. These concentrations are in the middle to lower part of the spectrum of values recorded for tropical forests. Accessions of nutrients in litterfall (kg ha&amp;supminus1; y&amp;supminus1;) ranged from 59 to 64 N; 1.9 to 2.4 P; 20 to 24 K; 34 to 63 Ca; and 9 to 16 Mg. These rates, particularly for N and P, are among the lowest recorded for tropical forests. There were no consistent between-site differences in total nutrient accessions in small litterfall. In terms of the contribution of litterfall to the accessions of nutrients to the forest floor, this suggests that the logged sites have recovered from the effects of selective harvesting within 25 y. Nutrient accessions at each site were distinctly seasonal, with maximum accessions occurring in the late dry season to late in the wet season. Leaf-fall accounted for the largest proportion of nutrient accessions over the study period, although at certain times accessions in both reproductive material and wood were significant. A cyclone which crossed the coast near the study sites resulted in large nutrient accessions over a short period but had little effect on the total annual accession. A comparison with previous studies of litterfall in Australian tropical rainforests indicates that nutrient return in litterfall is directly related to soil fertility.

Litterfall and Nutrient Cycling in Four Rain Forests in the Sringeri Area of the Indian Western Ghats

Small litterfall was collected at monthly intervals for 3 years from traps in two evergreen lowland rain forests, a lower montane (shola) forest, and a moist deciduous forest in the Western Ghats of Karnataka, India. The range of the mean annual total small litterfall (in t ha' yr1) was 1 1.6-13.9 and that for leaf litterfall was 8.4-10.6 t ha' yrI. The lowest values were for the moist deciduous forest and the highest for the lower montane forest. In all cases there was a seasonality of the litterfall with high weights during the dry season. The chemical composition of the litterfall showed generally high concentrations, which did not differ greatly between plots, and which reflected the similarly high soil nutrient status in all the plots. The moist deciduous forest had the highest leaf litterfall concentrations of phosphorus, potassium and calcium and the least of nitrogen. The small litterfall mass is much higher than that reported earlier for forests in nearby areas of the Ghats by Rai & Proctor (1986b) and the differences from the present study are not easy to explain.

Ecological studies on three contrasting Scottish oakwoods I. Site descriptions and small litterfall

Summary Three contrasting ancient Scottish oakwoods and their physical environment are described: Ross Point Wood (on podzolic soils) and North Gartfairn Wood (on gleys) on Loch Lomondside; and the Old Wood of Methven (on brown earths) near Perth. Small litterfall was measured for one year at each site. The production of total small litterfall was (t ha-1 yr-1): Ross, 3.61; Gartfairn, 4.48; and Methven, 5.37. Most small litterfall fractions followed the same rank order. Ross had the least litterfall input for all analysed nutrients (N, P, K, Na, Ca, Mg) and Methven the highest, except for Na and Mg which were highest at Gartfairn. The differences between the woods are as likely to involve past management practices as those involving their soils. However, there is some evidence that nutrients may be limiting production since the concentrations of litterfall nitrogen and phosphorus are least in the least productive site.

Litterfall and nutrient fluxes in two montane tropical rain forests, Colombia

ABSTRACTLitterfall was sampled during one year in two undisturbed Andean forests at altitudes of 2550 and 3370 m in the Colombian Cordillera Central. Total small litterfall at 2550 and 3370 m was 7.03 and 4.31 tha-1y-1respectively, of which 4.61 and 2.82 were leaves, 1.06 and 0.76 woody parts, 0.66 and 0.27 reproductive parts, 0.22 and 0.23 epiphytes, 0.47 and 0.23 unclassified.Clear differences were also found in nutrient concentrations, both between different litter fractions from one site and between equivalent litter fractions from different sites. Weighted mean concentrations for total small litterfall were (mgg-1, at 2550 and 3370m respectively): 11.7 and 7.3 for nitrogen; 0.86 and 0.44 for phosphorus; 8.4 and 3.1 for potassium. Comparison of nutrient concentrations in crown leaves and shed leaves indicated important reallocation of nitrogen (39% at both sites) and phosphorus (45% at 2550m, 65% at 3370m) before leaf shedding.The results for litterfall amounts, litter nutrient concentrations and reallocation of nutrients in the two forests are consistent with such data obtained in other montane forests in the wet tropics.

Structure and dynamics of a tropical dry forest in Ghana

Forest under low rainfall (averaging 745 mm yr- 1) on the Shai Hills in S.E. Ghana has redeveloped following cessation of farming in the 1890s. Forest stature is low, with a canopy at about 11 m, principally of three species, Diospyros abyssinica, D. mespiliformis and Millettia thonningii. Drypetes parvifolia and Vepris heterophylla are common understorey trees. Twelve species of woody liane were recorded. Species of thicket vegetation in the area were also present at low density. Most species are evergreen. Tree mortality averaged 2.3~o yr ~ and exceeded recruitment (1.5~ yr-1). Differences between species in mortality and recruitment were pronounced: canopy species showed a small decline in density; understorey species increased markedly and the thicket species declined. Seed production was very variable, but seedling establishment was very poor for all species. Seedling mortality was high (11 ~o yr - 1 ) especially for small seedlings. These population trends probably represent the latter stages of succession of forest regrowth after farming about 100 years ago. Compared with tropical rain forest, Shai Hills forest has similar relative tree diameter growth (1-3.5 ~o yr- 1), mortality and recruitment rates, and small-litter fall (5.52 t ha-1 yr- 1). Shai Hills forest differs from rain forest by its short stature, relatively few (evergreen) tree species, poor regeneration from seed, high soil nutrient status and low rainfall. Similar forests have been reported in east Africa and in parts of New Guinea. Abbreviations: dbh = diameter at breast height (1.3 m), gbh = girth at breast height. Nomenclature: follows Hutchinson & D alziel (1954-72), except where authorities are given.

Ecological Studies on Gunung Silam, a Small Ultrabasic Mountain in Sabah, Malaysia. II. Some Forest Processes

SUMMARY (1) The rates of several processes in the rain forests, at a range of altitudes, on an ultrabasic mountain, Gunung Silam, Malaysia, were investigated. In spite of the unusual soil chemistry, none of these processes occurred at an exceptionally low rate. (2) Herbivory (judged from the percentage area missing from large numbers of leaf samples of several species) in four plots was: 7 6% (330 m), 6 8% (610 m), 6 9% (790 m) and 7 1% (870 m). (3) Annual mortality of trees (?, 10 cm d.b.h.) was estimated over twelve or thirteen years in ten plots. This was (i): 0 025 (280 m), 0 012 (330 m), 0015 (410 m), 0 011 (480 m), 0 008 (540 m), 0 011 (610 m), 0 008 (700 m), 0 008 (790 m), 0 010 (790 m) and 0 016 (870 m). (4) Median diameter increment of tree boles was estimated over twelve or thirteen years in six plots. This was (mm year- ): 1 56 (280 m), 1 13 (330 m), 1 31 (480 m), 0 93 (610 m), 0 91 (790 m) and 0-77 (870 m). (5) Small litter fall was estimated from twenty 0 25 m2 litter traps in each of six plots over twelve months. It was (t ha-' year-'): 6 51 (280 m), 7 37 (330 m), 5 22 (480 m), 5 60 (610 m), 5 53 (790 m) and 4 80 (870 m). There was no correlation between small litter fall and median diameter increment. (6) Chemical analyses of the small litter fall showed a number of important features, including an excess of calcium concentrations over magnesium concentrations and relatively high concentrations of nickel. (7) Chemical analyses were made of the leaves of a large number of species in four plots. These suggested that the tree species rooted in ultrabasic soil have an ability to grow at low foliar nutrient concentrations and that they are able to concentrate calcium relative to magnesium. A comparison with the results of the litter-fall analyses suggested that there may be an excretion of nickel into the senescing leaves. (8) Shorea tenuiramulosa (Dipterocarpaceae) appeared to accumulate nickel and had up to 1 -0 mg'- nickel in its leaf dry matter. An unidentified Eugenia species (Myrtaceae) had 13-7 mg g' foliar manganese.

Nutrient content of litterfall in coniferous forest plantations in central Java, Indonesia

ABSTRACTProduction and nutrient content of small litterfall were studied for one year in four plantations of Agathis dammara ranging in age from 7 to 35 years old, in a 12-year-old stand of Pinus merkusii and in an approximately three-year-old shrub community dominated by Eupatorium species. The dense Pinus plantation produced considerably more litter (10 t/ha/yr, with 5.5 t/ha as needles) than any of the Agathis stands (2.6–6.2 t/ha/yr; 2.3–3.5 t/ha as leaves) or nearby Lower Montane Rain Forest (6.8 t/ha/yr; 5.4 t/ha as leaves). Litterfall in the Agathis forests increased with stand age. The shrubs produced sizeable amounts of litter (3.4 t/ha/yr). The various species responded differently to a drought occurring during the study period.Pine litter generally exhibited low nutrient concentrations (on average 9.2, 1.9, 2.5, 0.4 and 6.0 mg/g of calcium, magnesium, potassium, phosphorus and nitrogen respectively in needle litter), whilst concentrations in shrub litter were generally high (37.8, 4.9, 1.4, 1.05 and 21.5 mg/g for the same elements); Agathis litter usually showed nutrient concentrations that were intermediate between those for pine or shrub litterfall with only minor differences between stands. Comparison of the present findings with observations at other tropical sites suggests that nutrient content of litterfall in plantation forests may approach that of natural forests when the former become about 20 years old. Pine plantations may constitute an exception in this regard.

Ecological Studies in Four Contrasting Lowland Rain Forests in Gunung Mulu National Park, Sarawak: II. Litterfall, Litter Standing Crop and Preliminary Observations on Herbivory

SUMMARY (1) Small litterfall (leaves, wood ?2 cm diameter, renroductive parts, and trash) was compared on sites of 1 ha in each of four types of lowland forest in Gunung Mulu National Park, Sarawak, for quantity, seasonal distribution and the concentrations of nitrogen, phosphorus, potassium, sodium, calcium, magnesium and total phenols. The sampling period was 50 weeks for the sites in alluvial forest (AF), dipterocarp forest (DF) and heath forest (HF) and 42 weeks for the forest over limestone site (LF). (2) The total small litterfall was (t ha-' year-' ? 95% confidence limits): for the AF, 11.5 ? 1.9; DF, 8.8 ? 0.6; HF, 9.2 ? 1.2; and LF, 12.0 ? 1.3. A peak of litterfall occurred on all four sites during a May-June period of high rainfall before the driest time of the year. (3) The element concentrations in the litterfall differed greatly between each forest type. The concentrations of all elements (except calcium in samples from the LF) were below or within the ranges reported for other tropical forests and there was no consistent seasonal variation. The low calcium concentration in the DF litterfall and low nitrogen in the KF litterfall were notable. (4) Total polyphenol concentrations in the leaf litterfall were ranked HF > LF > DF > AP. (5) Large-wood litterfall was measured over a shorter period than the small litterfall. Virtually no wood over 10 cm diameter fell in the collection quadrats and the results for