Litterfall Components Research Articles

Nutritional Contribution Model of Litterfall for Adjacent Areas According to the Distance of Forest

The goal of this study is to evaluate the drift of litterfall from forest to adjacent areas, validate a method to estimate the drift with water balance, direction and speed of winds and quantify the nutrients of litterfall in nearby area of the forest patch as function of distance. This phenomenon can be considered an ecosystem service to improve soil quality of the agriculture crops around the forests by nutrient input coming from the litterfall. The experiment was installed in adjacent areas of the tropical forest at central region of the State of Minas Gerais, Brazil. The branches, reproductive material and leaves which fell were measured for three years into the forest and adjacents areas. The sampled nets were located on edge and equal distances from the edge. It?s analyzed and estimated the contribution of the litterfall components to adjacent areas by air. The quantity of litterfall by distance had large variation between adjacent areas. And it was confirmed that model estimated the leaf drift by distance with good precision.

Fine litterfall in the Brazilian Atlantic Forest

AbstractLitterfall is an essential component of tropical forest productivity, transferring nutrients from the vegetation back to soils. Here, we summarize the data from 105 estimates of fine litterfall production from 45 sites in the Atlantic Forest domain, including two types of forests, evergreen and seasonal, and two successional stages, secondary and old growth. The overall litterfall average was 8.0 ± 2.5 Mg/ha. Litterfall was significantly in higher seasonal forests than in evergreen forests and in old growth versus secondary forests. Leaves were the major component of litterfall, contributing 68 percent to the total. The second most important component was branches, contributing 22 percent, followed by reproductive organs (flowers and fruits), at 6 percent. Accurate measurements of tropical forest productivity are crucial for estimating their role in sequestering atmospheric carbon, and we suggest some ways to standardize litterfall sampling to obtain better estimates.

Relación entre la producción de hojarasca y las condiciones edáficas en bosques pluviales tropicales del Chocó Biogeográfico, Colombia

Litter production (NPP litterfall ) is one of the main components of net primary productivity (NPP) in forest ecosystems. Such NPP litterfall is determined considerably by the soil conditions in tropical rainforests. To evaluate this hypothesis five 1-ha permanent plots were established in two forests of Choco (Opogodo and Pacurita) where NPP litterfall was measured in 125 collectors, monthly-monitored for a year. In addition, basic soil-fertility parameters were measured and related to the NPP litterfall . It was observed that both forests exhibited nutrient-poor soils, but with higher sand content, total N and organic matter (OM) in Opogodo. The NPP litterfall was similar in both forests (7.82 t ha -1 yr -1 in Opogodo, and 7.35 t ha -1 yr -1 in Pacurita). Also, the litter-fall components with greatest contribution were leaves (> 60%), stems (19%) and miscellaneous (14%). Total NPP litterfall showed a weak negative correlation with the percentage of silt. Leaf litter production was positively associated with sand content, pH, O.M. and total nitrogen; whereas, it was negatively correlated with aluminum (Al), effective cation exchange capacity (ECEC) and silt. In general, correlations between NPP litterfall and soil parameters were weak, apparently due to the small variation in soil fertility and low availability of some nutrients (phosphorus and calcium). Therefore, these results partially confirmed the hypothesis of soil-fertility limitation upon NPP in the forests of Choco.

Mistletoes and epiphytic lichens contribute to litter input in Nothofagus antarctica forests

Litter input is one of the key components that define nutrient cycling in forests and the majority of studies only consider the tree components of litterfall. However, epiphytic species can play a crucial role in litter input throughout the growing season. This work evaluates changes in litter production by mistletoe (Misodendrum sp.) and epiphytic lichen (Usnea sp.), related to crown cover in mature unmanaged, second-growth and managed (thinned for silvopastoral use) forests in Tierra del Fuego (Argentina). We used plastic traps to collect litterfall biomass from trees, lichens and mistletoes on a monthly basis over three consecutive years. Tree litter was considerable during autumn (March to May), which is typical of Nothofagus deciduous species in the Southern hemisphere. In contrast, peak litterfall from mistletoes and lichens occurred during spring and summer seasons. Tree litter (1954–3398 kg dry matter ha−1 year−1) was correlated with crown cover gradient being highest in second-growth forests and lowest in thinned sites. While litter input from mistletoes did not vary among forest types (307–333 kg dry matter ha−1 year−1), lichen litter (11–40 kg dry matter ha−1 year−1) was higher in unmanaged and thinned mature forests despite differences in tree crown cover. Contrary to what we expected, the management practices investigated here did not affect the biomass of canopy communities compared to unmanaged mature forests. Mistletoes and lichens significantly increased the spatial (forest type) and temporal complexity (extended period of falling) of litterfall in Nothofagus antarctica forests. This study provides a starting point to understand the ecological relevance of canopy communities in the Patagonian forests of southern Argentina.

Vertical distribution of Cu, Ni and Zn in Brunic Arenosols and Gleyic Podzols of the supra-flood terrace of the Słupia River as affected by litho-pedogenic factors

Abstract The aim of the study was to assess the influence of lithological and pedogenic factors in the shaping of Cu, Ni and Zn distribution patterns in the profiles of Brunic Arenosols and Gleyic Podzols of the lower supra-flood terrace of the Słupia River, which is located outside the range of significant anthropogenic sources of pollution with these metals. The contents of the investigated metals were analysed in aqua regia extracts of samples collected from three profiles of Brunic Arenosols, formed from river sands, and three profiles of Gleyic Podzols, formed from river sands transformed by eolian processes. In general, river sands contained higher amounts of Ni and Zn (2.6 - 6.9 mg·kg-1 Ni; 10.3 - 16.2 mg·kg-1 Zn) compared to eolian sands (1.2 - 2.4 mg·kg-1 Ni; 3.3 - 17.3 mg·kg-1), while the content of copper tended to be higher in eolian sands (1.3 - 1.9 mg·kg-1) than river sands (0.1 - 1.5 mg·kg-1). The observed differences between the two types of sand are due to the loss of fine granulometric fractions and various minerals during eolian processes. Higher concentrations of the investigated metals in soil solum as compared to parent material are due to their uptake from deeper parts of the soil by roots and subsequent return to the soil surface as a component of litterfall. Therefore, the highest concentrations of Cu, Ni and Zn were observed in ectohumus. In the mineral component of the soil, the highest concentrations were observed in organic matter-rich A and B horizons, which indicate close interactions between heavy metals, humic substances and iron oxides. The vertical distribution of the investigated metals in the profiles of Gleyic Podzols indicates their leaching during podzolization. The observed contents of Cu, Ni and Zn, both in Brunic Arenosols and Gleyic Podzols, were lower than the geochemical background, which confirms that anthropogenic contamination of the studied area with these metals is marginal

Allometric relationships among different components of forest litterfall in China

Aims Litterfall is a measure of the metabolic product of forest plants during their growth. It plays an important part in the fluxes and recycling of matter and energy. The metabolic theory of ecology posits that there exist al- lometric relationships among different organs of a plant. However, all these scaling relationships do not take into account the potential contribution of litterfall, and hence much remains unknown about the allometric relation- ships among the different components of litterfall. In this study, we analyze the allometric relationships between component as well as the allometric relationships of the total litterfall with different components. Methods We compiled data on forest litterfall from the literature published in Chinese journals and divided these data into evergreen forests and deciduous forests for analysis of the allometric relationships between components as well as the allometric relationships of the total litterfall with different components.Important findings We found that the average amount of litterfall was 3 810.34 kg·hm–2·a–1, 1 019.07 kg·hm–2·a–1, and 767.95 kg·hm–2·a–1as leaves, branches, and propagules, respectively. Compared with precipita- tion and stand age, temperature had a greater effect on forest litterfall production. An isometrical relationship was observed between leaves and the total litterfall, as LL ∝ LT 0.96(LL, leaf litterfall; LT, total litterfall); whereas an allometric relationship was found between the propagules and the total litterfall as LP ∝ LT 1.84(LP, propagule lit- terfall), and between the branches and the total litterfall as LB ∝ LT 1.61(LB, branch litterfall), respectively. Signifi- cant allometric relationships were also observed among different components, with exponents all less than 1.0 in each case. Allometric relationships of the total litterfall with different components were approximately the same between the evergreen forests and the deciduous forests. The allometric relationships found in this study provide valuable insights into the investigation and estimation of forest productivity.

Dynamics, structure and properties of plant litterfall in a 120-year old beech stand in Middle Pomerania between 2007-2010

Abstract Studies of plant litterfall mass, its dynamics, structure and chemical composition were conducted between 2007.2010 in a 120-year old beech (Fagus sylvatica L.) stand located in Middle Pomerania. The annual mass of litterfall during the study period ranged from 2.793 to 5.398 t·ha.1 and its maximum was observed during the seed year. Leaves were the major component of plant litterfall and their contribution was 82.4.84.5% in the non-seed years and 47.2% during the seed year. Inflorescences, seeds, and seed coats were important components of litterfall during the seed year and accounted together up to 39.8% of the total litterfall mass. Particular fractions of litterfall significantly differed in the chemical composition. The highest concentrations of nitrogen, phosphorus and potassium were noticed in seeds and leaves collected in spring and the maximum content of calcium was observed in leaves collected in autumn. The weighted mean annual concentrations of nitrogen ranged within 0.81.1.13%, phosphate . 0.126.0.153%, potassium . 0.298.0.485% and calcium . 0.416.0.583%. The influx of elements with litterfall to the soil was: 167.3.225.9 kg·ha-1 of ash, 23.2.61.0 kg·ha-1 of nitrogen, 3.6.7.6 kg·ha-1 of phosphorus, 8.3.26.2 kg·ha-1 of potassium and 15.3.22.4 kg·ha-1 of calcium.

Phenological traits of the mangrove Rhizophora stylosa Griff. at the northern limit of its biogeographical distribution

The vegetative and reproductive phenology of the subtropical mangrove species Rhizophora stylosa was investigated at Manko Wetland, Okinawa Island, Japan. We assessed phenology using litterfall data over four years. Leaf and stipule litterfall occurred throughout the year, with distinct seasonal patterns. Kendall’s coefficient of concordance, W, revealed that the monthly changes in leaf and stipule litterfall were strongly and significantly concordant among years. Leaf litterfall was significantly correlated with monthly maximum wind speed and monthly day length, and stipule litterfall was significantly correlated with monthly mean air temperature and relative humidity. Branch litterfall showed no clear monthly pattern and correlated well with monthly maximum wind speed. Mean total litterfall was 11.2 Mg ha−1 year−1, with the largest component being vegetative organs (78.7 %). Flower, fruit, and propagule litterfall were all highest in summer and lowest in winter. The W values revealed that most reproductive organs in litterfall had significant monthly trends. Flower and fruit litterfall were significantly correlated with monthly day length and monthly mean air temperature, respectively. The average development periods from flower buds to flowers, fruits, and mature propagules were approximately 2–3 months, 4–5 months, and 11–12 months, respectively. Except for branches, all vegetative and reproductive components of litterfall had approximately one year cycles.

重庆酸雨区马尾松林凋落物特征及对干旱胁迫的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 重庆酸雨区马尾松林凋落物特征及对干旱胁迫的响应 DOI: 10.5846/stxb201108301270 作者: 作者单位: 1. 中国林业科学研究院森林生态环境与保护研究所;2. 重庆市林业科学研究院,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所,重庆江北区铁山坪林场 作者简介: 通讯作者: 中图分类号: 基金项目: 中挪合作项目(193725/S30);林业公益性行业科研专项(200904005, 200904056, 201104005-02);国家林业局森林生态环境重点实验室和重庆市三峡库区森林生态保护与恢复市级重点实验室联合资助 The litter-fall characteristics and their response to drought stress in the Masson pins forests damaged by acid rain at Chongqing, China Author: Affiliation: Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry;the Forestry Academy of Chongqing,Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:气候变化导致干旱等极端气象事件增多,这将和酸雨等环境胁迫一起影响森林健康。在重庆铁山坪于2010年监测了酸雨区受害马尾松林的凋落物数量和组分特征及其对土壤水分的响应。结果表明:马尾松林月凋落物量呈"双峰"模式,第1高峰出现在8-9月份伏旱期,第2高峰出现在冬季休眠的12月份;枯死针叶占年凋落物总量的48.42%,凋落物组分比例为针叶>树枝>阔叶>有机碎屑>树皮及球果;除阔叶凋落物外,其它组分凋落物在伏旱期均明显增加,与土壤湿度显著负相关,特别是30-40 cm和40-50 cm土层;此外,马尾松林凋落物量还与表征气象干旱的气象指标显著相关。和健康森林相比,酸雨区受害林木的细根数量变少和分布变浅导致马尾松林针叶的年形成量与凋落量减少,但枝凋落量及其占总凋落量的比例增大;凋落发生对干旱胁迫更加敏感,年凋落物量的时间分布更集中在伏旱期;酸雨和干旱的双重胁迫将进一步恶化研究地区的森林健康状况。 Abstract:The health condition of forests especially those already damaged in the acid rain region will be increasingly influenced by the increasing extreme drought events caused by climate change. Understanding the forest health response to multiple stresses is a new challenge. The characteristics of litter-fall can be used as an important indicator to reflect forest health condition and its response to environmental stresses. The aim of this study is to detect how drought stress affect the litter-fall characteristics of forests for a better understanding and more precise prediction of the forest health decline in the acid rain region of south China. Masson pine (Pinus massoniana) is a native and widely distributed tree species in south China. it is also one of the most important tree species used for forestation and widely damaged by acid rain. The litter-fall quantity and its components (dead needles, green needles, twigs, debris, bark and cones, and broad leaves of other tree species) in the Masson pine forest stands were monitored at Tieshanping of Chongqing in 2010, and their responses to soil moisture was analyzed through Pearson correlation. The results showed that the monthly variation of litter-fall presented a "two-peak" pattern. The highest peak appeared in the dry-summer period of August-September with the lowest soil moisture and amounted to 2.30 t/hm2; the second peak appeared during the dormancy period of December and was only 0.65 t/hm2; the amount of litter-fall in the two peak periods accounted for 49.56% of the annual total (5.96 t/hm2) in 2010. The annual dead needle was 2.89 t/hm2; it accounted for 48.42% of the annual total of litter-fall. The order of weight percentage of the litter-fall components was: needles > twigs > broad leaves > debris > bark and cones. The variation of monthly dead needle amount well presented the variation of total litter-fall amount. The monthly proportion of dead needle to total litter-fall was almost the highest in the whole year and fluctuated from 32.8% to 95.7%. The monthly variation of broad leaves also presented a "two-peak" pattern, but the highest peak appeared in the period of April-May and the period of November-December respectively. The monthly proportion of the litter-fall components of green needles, bark and cones were always the lowest and reached maximum in August. The monthly proportion of debris reached to maximum in the period of April-May and during the dry-summer period of August respectively. The monthly proportion of twigs presented only one peak in September. On the whole, the amount of all components of litter-fall, but except the broad leaves, presented an obvious increase during the dry-summer period and significantly negatively related with soil moisture, especially in the soil layers of 30-40 cm and 40-50cm. In addition, the litter-fall amount presented a significantly positive relation with air temperature, potential evaporation and solar radiation (P<0.05), but a significantly negative relation with air humidity (P<0.05). All these relation with weather parameters reflected the dependence of litter-fall to drought stress. Compared with healthy forests, the fine roots of the studied Masson pine stands were decreased and shallower-distributed as the results of long-term acid rain impact, and the quantity of newly grown needles and their litter-fall was reduced, but the quantity of dead branches and their proportion in total litter-fall was increased. The variation of litter-fall of Masson pine forests in the acid rain region of Chongqing became quite sensitive to drought stress, and the litter-fall more distributed in the dry-summer period; this means that the double stresses of acidification and drought will further worsen the forest health condition in the studied region. 参考文献 相似文献 引证文献

Vegetative and reproductive phenology of the mangrove Bruguiera gymnorrhiza (L.) Lam. on Okinawa Island, Japan

Vegetative and reproductive phenology of the subtropical mangrove Bruguieragymnorrhiza was investigated at Manko Wetland, Okinawa Island, Japan. Phenology was assessed using litterfall data over 4 years. Leaf and stipule litterfall occurred throughout the year, with distinct seasonal patterns. Kendall’s coefficient of concordance, W, revealed that the monthly changes in leaf and stipule litterfall were strongly and significantly concordant among years. Leaf litterfall was linked to monthly day length and maximum wind speed, and stipule litterfall was linked to monthly mean air temperature, monthly rainfall, and maximum wind speed. Branch litterfall showed no clear monthly pattern, but tended to vary with monthly maximum wind speed. Mean leaf longevity was 19 months. Mean total litterfall was 10.1 Mg ha−1 year−1, with the largest component being vegetative organs (58 %). Flower and propagule litterfall were highest in autumn and summer, respectively, and lowest in winter. The W values revealed that, of the reproductive organs, only flower litterfall had a significant monthly trend. Flower litterfall was correlated with monthly mean air temperature and relative humidity. The average development periods from flower buds to flowers and from flowers to mature propagules were approximately 1 and 8 months, respectively. It took 9 months to produce mature propagules from flower buds. Except for branches, all vegetative and reproductive components of litterfall had clear annual cycles.

Litterfall of three subtropical mangrove species in the family Rhizophoraceae

This study was conducted to evaluate and compare the litterfall dynamics of three mangrove species in the family Rhizophoraceae: Rhizophora stylosa, Kandelia obovata, and Bruguiera gymnorrhiza, in Manko Wetland, Okinawa Island, Japan. Over 3 years, these species showed highest litterfall of leaves and stipules in summer and the lowest litterfall in winter. Litterfall of flowers and fruits peaked in July for R. stylosa, and in August and again in October–November for K. obovata. Litterfall of flower buds, flowers, and propagules occurred throughout the year for B. gymnorrhiza, but was highest in summer. Litterfall of propagules was highest in September and May for R. stylosa and K. obovata, respectively. Kendall’s coefficient of concordance revealed that the monthly changes for leaf, stipule, flower, and fruit litterfalls of all the species were strongly and significantly concordant among the years. The conversion rate of flowers to propagules was 2.3 % in R. stylosa, 5.9 % in K. obovata, and 10.3 % in B. gymnorrhiza. Total annual litterfall in R. stylosa was significantly different from K. obovata and B. gymnorrhiza; however, the latter two species showed no significant differences. Leaves contributed the most to the total litterfall of all three species, and represented 58.4, 54.0, and 50.4 % of the total litterfall for R. stylosa, K. obovata, and B. gymnorrhiza, respectively. Except for branches and flower bud primordia, all other components of litterfall had clear annual cycles for all three species. Rhizophora stylosa and K. obovata showed a negative correlation between leaf production and reproductive organ production, but B. gymnorrhiza tended to increase leaf production with increasing reproductive organ production.

Influence of forest tending (Soopkakkugi) works on litterfall and nutrient inputs in a Pinus densiflora stand

This study was conducted to examine litterfall and nutrient inputs following forest tending works (FTW) which are one of the most important forest management activities in Korea. We measured litterfall and nutrient (C, N, P, K, Ca, Mg) inputs from needle litter in FTW and non-FTW (control) stands of approximately 40-year-old red pine (Pinus densiflora S. et Z.) forests in the Hwangmaesan Soopkakkugi model forest in Sancheonggun Gyeongsangnam-do, Korea. Seasonal inputs of litterfall components such as needle, broadleaf, branch, bark and total litter inputs followed a similar pattern between the FTW and control stands. Annual average needle and total litterfall were significantly lower in the FTW (2483 kg ha−1 yr−1; 4038 kg ha−1 yr−1) than in the control stands (3377 kg ha−1 yr−1; 5589 kg ha−1 yr−1) during the study period. Nitrogen concentration of needle litter was significantly affected by FTW (P < 0.05), while other nutrient (C, P, K, Ca, Mg) concentrations were not significantly different between the FTW and control stands. There was a significant difference (P < 0.05) in the organic C, N, P and Ca inputs by needle litter following FTW, whereas K and Mg inputs were not significantly different between the FTW and control stands. The results indicate that the reduction of litterfall and nutrient inputs following FTW can be attributed to reduced needle litterfall and vary considerably nutrient cycle in FTW stands.

Seasonal intrusion of litterfall from non-native pine plantations into surrounding native woodland: Implications for management of an invasive plantation species

Radiata pine (Pinus radiata) is commonly grown throughout the world as a major plantation species. Non-native radiata pine plantations are often established as monocultures amongst large tracts of remnant native vegetation. While the direct impacts on native biodiversity of such vegetation replacement have been well documented, much less is known about how plant litterfall from such plantations influences ecosystem dynamics beyond the confines of the plantation limits. In this study, we assessed the inputs of plant litterfall from radiata pine plantations into surrounding native woodland vegetation over a two-year period in south-eastern Australia. We found that pine litter was a significant and even dominant component of litterfall at certain times of the year, typically autumn and winter, when quantities of pine needles falling were up to three times the fall of native leaves. Pine litter was found to be lower in quality than native litter, containing less carbon (C) and nitrogen (N) and having a higher C:N ratio than native litter. Although the comparatively larger inputs of pine litter resulted in C and N inputs that were 2–3 times those of native litter during some seasons, the influx of low-quality pine litter is likely to decompose slowly and immobilise N, thereby limiting the availability of N for plant growth in the long term. The intrusion of large quantities of pine litter into native eucalypt woodland may have a suite of further short and long term impacts on native biodiversity through a number of mechanisms including alteration of leaf-litter invertebrate communities, increased fire intensity and changes in microclimate. These impacts may be alleviated by preventing pine litter entering woodland communities through the use of modified buffer zones and by employing appropriate plantation design. We discuss the merits and shortfalls of various options available to land mangers to minimise pine-litter intrusion into adjacent native woodlands.

Carbon and nitrogen status in litterfall of a red pine stand with varying degrees of damage from pine wilt disease

We evaluated the carbon (C) and nitrogen (N) status of litterfall in a natural red pine (Pinus densiflora ) stand damaged by pine wilt disease in Jinju City, which was one of the areas severely affected by the disease in Korea. A significant cor relation (P < 0.05) was found between tree density and basal area and the C and N status of litterfall components, but C and N status was not correlated with mean diameter at breast height in the pine wilt disease stands. Needle-litter C and N concentrations were linearly related (P < 0.05) to basal area in pine wilt disease stands. Needle-litter C concentration decreased with a decrease in damage intensity due to pine wilt disease, whereas litter N concentration increased with an increase of basal area in pine wilt disease stands. The linear regression equations developed for litterfall C and N inputs were significant ( P < 0.05), with basal area accounting for 50-86% of the variation, except for cone and flower litter. The results indicated that the incidence of pine wilt disease could impact the quality and quantity of C and N in litterfall of pine stands suffering from pine wilt disease.

Litter production and nutrient input via litterfall in Quercus mongolica forest at Mt. Worak National Park

In this study, litter production, the nutrient concentration of each component of litterfall, and the amount of nutrient input to the forest floor via litterfall were assessed for four years from May 2005 through April 2009 in a Quercus mongolica forest in Mt. Worak National Park. The average amount of leaf litter, branch and bark, reproductive organs (flowers and nuts), and miscellaneous categories for 4 years were <TEX>$2.921{\pm}0.242$</TEX>, <TEX>$1.112{\pm}0.288$</TEX>, <TEX>$0.625{\pm}0.176$</TEX> and <TEX>$0.837{\pm}0.209\;t\;ha^{-1}\;y^{-1}$</TEX>, respectively. The average percentage of leaf litter, branch and bark, reproductive organs and miscellaneous categories for 4 years were <TEX>$53.2{\pm}7.31$</TEX>, <TEX>$20.2{\pm}4.43$</TEX>, <TEX>$11.4{\pm}2.59$</TEX> and <TEX>$15.2{\pm}3.35%$</TEX>, respectively. The amount of total litterfall in 2005, 2006, 2007, and 2008 was 5.438, 5.864, 5.669 and <TEX>$5.009\;t\;ha^{-1}\;y^{-1}$</TEX>, respectively. The average amount of litterfall for 4 years was <TEX>$5.495{\pm}0.368\;t\;ha^{-1}\;y^{-1}$</TEX>. The average amount of N, P, K, Ca, and Mg returned to the forest floor via litterfall for 4 years in this Quercus mongolica forest were <TEX>$53.4{\pm}5.35$</TEX>, <TEX>$3.8{\pm}0.88$</TEX>, <TEX>$17.8{\pm}1.37$</TEX>, <TEX>$17.2{\pm}2.21$</TEX> and <TEX>$5.8{\pm}0.55\;kg\;ha^{-1}\;y^{-1}$</TEX>, respectively.

Carbon and nitrogen inputs by litter fall in fertilized and unfertilized larch plantations

This study was carried out to evaluate the effects of fertilization on carbon and nitrogen dynamics by litter fall of a 36-year-old larch (Larix leptolepis) plantation in the Sambong Exhibition Forests, Gyeongsangnam-do, Korea. Litter was collected monthly between April 2003 and May 2006. Seasonal inputs of litter fall components such as needle, broad leaf, branch, bark and total litter inputs followed a similar pattern between fertilized and unfertilized plots. The annual amounts of the litter components were not significantly different (P > 0.05) between fertilized and unfertilized plots. Mean needle litter fall was similar between the fertilized (2564 kg ha−1 yr−1) and unfertilized plots (2501 kg ha−1 yr−1) and total annual litter fall averaged 3552 kg ha−1 yr−1 in the fertilized and 3541 kg ha−1 yr−1 in the unfertilized plots during the sampling period. Proportion of needle litter fall was slightly higher in the fertilized (72.2%) than in the unfertilized (70.8%) plots. Carbon concentrations of needle litter were not significantly affected by fertilization (P > 0.05), while there was a significant fertilization effect on nitrogen concentrations with high nitrogen concentrations of needle litter in the fertilized (7.7 g kg−1) compared with the unfertilized (6.8 g kg−1) plots. There was no significant difference (P > 0.05) in the organic carbon inputs by needle litter between the fertilized and unfertilized plots, whereas annual nitrogen inputs were significantly higher in the fertilized (17.7 kg N ha−1 yr−1) than in the unfertilized (15.6 kg N ha−1 yr−1) plots. The results indicated that nitrogen dynamics by litter fall could be affected by fertilization, but a minimal impact to carbon dynamics by litter fall in the larch plantation.

Produção e composição química da folhada em soutos submetidos a diferentes técnicas de mobilização do solo

The objectives of this study were to determine the influence of different soil tillage systems on chestnut tree (Castanea sativa) productivity. The plots, established in Macedo de Cavaleiros, were given to three treatments: chisel ploughing, three times per year (traditional system) (T1), minimum tillage with disc plough, twice a year (T2) and zero tillage (T3). Vegetation was controlled either by sheep or by cutting. Litter was collected from April 1996 to March 1999. The largest litterfall production was obtained in T3, which may be related to the fact of roots not being damaged. In all treatments, leaves made the highest contribution to total litter, followed by burs and nuts. In relation to the chestnut fruit, the highest production was obtained in T3, followed by T2 and T1. The largest nut production in T2 than in T1 may be related to the more damaging effect that chisel ploughing has on the root system when compared to disc ploughing. In general, the lowest nutrient concentration occurred in T1, which is related not only with the lower litter production but also with the nutrient concentration in the different litterfall components. In general, it was the lowest in T1, mainly in leaves.

Litter Production and Nutrient Contents of Litterfall in Oak and Pine Forests at Mt. Worak National Park

Litter production, nutrient contents of each component of litterfall and amount of nutrients returned to forest floor via litterfall were investigated from May 2005 through April 2006 in Quercus mongolica, Quercus variabilis and Pinus densiflora forests at Mt. Worak National Park. Total amount of litterfall during one year in Q. mongolica, Q. variabilis and P. densiflora forests was 542.7, 459.2 and <TEX>$306.9\;g\;m^{-2}\;yr^{-1}$</TEX>, respectively. Of the total litterfall, leaf litter, branch and bark, reproductive organ and the others occupied 50.3%, 22.7%, 10.1 % and 16.9% in Q. mongolica forest, 81.9%, 7.2%, 3.1% and 7.9% in Q. variabilis forest, 57.4%, 12.8%, 5.6% and 24.1 % in P. densiflora forest, respectively. Nutrients concentrations in oak litterfall were higher than those in needle litter. N, P, K, Ca and Mg concentration in leaf litterfall were 13.8, 1.1, 7.2, 4.2 and 1.3 mg/g for Q. mongolica forest, 10.5, 0.7, 3.2, 3.7 and 1.6 mg/g for Q. variabilis forest, 5.3, 0.4, 1.2, 2.8 and 0.6mg/g for P. densiflora forest, respectively. The amount of annual input of N, P, K, Ca and Mg to the forest floor via litterfall was 43.36, 2.89, 21.38, 23.31 and <TEX>$5.62\;kg\;ha^{-1}\;yr^{-1}$</TEX> for Q. mongolica forest, 32.28, 2.01, 10.23, 20.29 and <TEX>$7.78\;kg\;ha^{-1}\;yr^{-1}$</TEX> for Q. variabilis forest, 15.80, 1.04, 3.99, 9.70 and <TEX>$2.10\;kg\;ha^{-1}\;yr^{-1}$</TEX> for P. densiflora forest, respectively.

Litter production in aQuercus suberforest of Montseny (NE Spain) and its relationship to meteorological conditions

From 1996 to 2002 the monthly litterfall in a Quercus suber forest ecosystem of Montseny (NE Spain) was recorded and its relationship to meteorological variables was statistically analysed. The average annual production (477 g m −2 yr −1 ) was similar to those found in other Mediterranean evergreen forests with relatively high rainfall. The main components were the leaves (55% of the total biomass), followed by acorns (22%) and twigs (16%). Litter production was highest during May and June, when the majority of the old leaves fell. When the meteorological conditions were favourable, a second leaf fall collection was observed. Acorn production in 2001 was about nine times that of the previous years, indicating a mast year. In general, the different litterfall components were highly correlated in time except for the acorns. Interannual covariation was significant for leaves/twigs and leaves/catkins. Catkins were the most variable component with also strong seasonality, acorns were also very variable with low seasonality, while leaves were less variable and with the strongest seasonality. After accounting for seasonal covariation, there were significant effects of rainfall on twig litterfall and of temperature on leaf litterfall, the years with highest leaf litterfall being the hottest. litterfall / Iberian Peninsula / coark oak / Mediterranean climate / weather

Temporal and structural effects of stands on litter production in Melaleuca quinquenervia dominated wetlands of south Florida

Melaleuca quinquenervia dominates large areas of the Florida Everglades in the southeastern USA where it has transformed sedge-dominated marshes into melaleuca forests. Despite its prevalence, very little is known about the ecology and stand dynamics of this invasive tree. We delineated large-, intermediate-, and small-tree stands in non-flooded, seasonally flooded and permanently flooded areas of Florida in 1997, measured their biological attributes, and then quantified litterfall components for 3–4 year periods. Melaleuca wood components and mature seed-capsules comprised the largest and the smallest portions of aboveground biomass, respectively, while leaves, fine stems, mature fruits, bud scales, floral structures, and residues represented decreasingly smaller fractions of the litter during the succeeding year. Dry weight proportion of leaves in litter was greatest (80.9%) in non-flooded and least (69.1%) in permanently flooded habitats. It was also greatest in small (85.6%) and least in large (64.7%) tree stands. Reproductive structures and mature-fruit fractions in litter were highest in large-tree stands whereas the bud-scale fraction showed no relationship to tree size. Seasonally flooded habitats had the most litterfall, wherein small-, intermediate-, and large-tree stands generated 0.662, 0.882, and 1.128 kg m 2 yr 1 , respectively. Dry weight of stems, leaves, bud–scales, floral structures, and mature fruit fractions in litter increased as the predominant size of the trees in the stand increased. Total annual litter production was highest during 1999–2000. Leaf fall occurred year-round with maximal amount during April, July, and October. Highest amounts of bud scales and floral structures fell during October–January, which corresponded with flushes of vegetative growth and major flowering events. Overall, melaleuca alone accounted for nearly 99% of the total litterfall dry weight in all habitats and months sampled. The amount of non-melaleuca litter was greater in small-tree stands than in intermediate- or large-tree stands. Litterfall data of this nature will be helpful in detecting changes occurring in melaleuca canopies in response to biological control impact and in prescribing site-specific management strategies.