Distribution patterns of tree,understorey, and detritus biomass in coniferous and broad-leaved forests of Western Himalaya,India

Forest biomass pools are the major reservoirs of atmospheric carbon in both coniferous and broad-leaved forest ecosystems and thus play an important role in regulating the regional and global carbon cycle. In this study, we measured the biomass of trees, understorey, and detritus in temperate (coniferous and broad-leaved) forests of Kashmir Himalaya. Total ecosystem dry biomass averaged 234.2 t/ha (ranging from 99.5 to 305.2 t/ha) across all the forest stands, of which 223 t/ha (91.9–283.2 t/ha) were stored in above- and below-ground biomass of trees, 1.3 t/ha (0.18–3.3 t/ha) in understorey vegetation (shrubs and herbaceous), and 9.9 t/ha (4.8–20.9 t/ha) in detritus (including standing and fallen dead trees, and forest floor litter). Among all the forests, the highest tree, understorey, and detritus biomass were observed in mid-altitude Abies pindrow and Pinus wallichiana coniferous forests, whereas the lowest were observed in high-altitude Betula utilis broad-leaved forests. Basal area has showed significant positive relationship with biomass (R² = 0.84–0.97, P < 0.001) and density (R² = 0.49–0.87). The present study will improve our understanding of distribution of biomass (trees, understorey, and detritus) in coniferous and broad-leaved forests and can be used in forest management activities to enhance C sequestration.     

The influence of coppiced teak (Tectona grandis L.F.) regrowth and roots on intercropped maize (Zea mays L.)

Trenching and shoot removal showed the relative influences of living roots and the canopy cast by teak (Tectona grandis L.F.) coppice regrowth on the growth and yield of interplanted maize (Zea mays L.). Teak and maize were planted at 1.8 × 1.8 m and 0.3 × 1.8 m spacing respectively.Competition for light started about four weeks after planting and caused etiolated height growth of maize. When combined with root competition it caused stunted growth. Shading also substantially reduced total dry matter production, grain yield, number of cobs per plant, average cob weight, and weight of grains per cob of maize (P<0.01). Living teak roots alone did not have a significant effect (P>0.05) on maize height growth, total dry matter production, grain yield, number of cobs per plant,average cob weight and weight of grains per cob. However, combined with shading, living roots of teak appreciably reduced total dry matter yield and average cob weight of maize (P<0.01).     

Soil microarthropod populations under natural and planted fallows in southwestern Nigeria

Microarthropods, such as soil mites (Acari) and springtails (Collembola), with body width between 0.08 mm and 0.5 mm play important roles in soil fertility maintenance through their regulatory activities in decomposition and nutrient turnover. Observations were made at IITA, Ibadan, southwestern Nigeria to evaluate the effects of natural regrowth of vegetation — mainly the shrub Chromolaena odorata — and three planted woody fallow species (Acacia leptocarpa, Senna siamea, and Leucaena leucocephala) on soil microarthropods in a degraded Alfisol. Populations of soil microarthropods were higher in the rainy season than the dry season, and populations were greater under natural fallow than for continuous cropping with maize (Zea mays) and cassava (Manihot esculenta). Populations of soil microarthropods were comparable under leucaena and natural fallow, but populations in the rainy season were 38% higher under senna than natural fallow and 36% higher under acacia than natural fallow. Regression analysis indicated that soil microarthropod population under fallow species was positively correlated with the lignin contents of leaf litter.This revised version was published online in November 2005 with corrections to the Cover Date.     

Long-term response of planted conifers, natural regeneration, and vegetation to harvesting, scalping, and weeding on a boreal mixedwood site

This study reports 14th-year response of a boreal mixedwood stand to different harvest intensities (uncut, 50% partial cut with and without removal of residuals after 3 years, and clearcut), spot site preparation treatments (none and scalped), and chemical weeding frequencies (none, single, and multiple) in northeastern Ontario. The response variables include the survival and growth of planted white spruce (Picea glauca [Moench] Voss) and jack pine (Pinus banksiana Lamb.), height and density of natural regeneration and shrubs, and cover of shrubs and non-woody vegetation. Harvesting and weeding generally improved survival and growth of planted trees, although white spruce survival did not significantly differ among the three weeding frequencies. Harvesting tended to increase heights of hardwood (mostly trembling aspen (Populus tremuloides Michx.)) and conifer (largely balsam fir (Abies balsamea (L.) Mill.).) natural regeneration, cover and density of shrubs, and cover of herbs, lichens, and ferns. Chemical weeding reduced height, density and cover of shrubs, height and density of hardwood regeneration, and fern cover, but increased moss and lichen cover. Spot scalping did not significantly affect planted seedling, natural regeneration, or the vegetation.Maximum survival and growth of planted white spruce and jack pine were achieved using a combination of clearcutting and multiple weeding. However, partial cutting followed by a single weeding produced acceptable survival and reasonable growth of planted trees, particularly for white spruce. Partial canopy removal alone substantially reduced the amount of hardwood regeneration, relative to clearcutting, but did not adequately suppress understory shrubs. Significant improvement in seedling growth following multiple weedings was evident primarily in the complete canopy removal treatments: 50% partial cut with removal of residuals after 3 years and clearcut. While the effects of harvesting and weeding on planted crop trees found in the 5th-year assessments generally persisted at year 14, survival decreased, likely due to light competition from developing hardwood and shrubs.     

Response of planted beech (Fagus sylvatica L.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) saplings to herbaceous and small shrubs control on clearcuts

The reaction of young beech (Fagus sylvatica L.) and Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) saplings on competition of two types of vegetation—(1) gramineous with mainly Agrostis capillaries, Calamagrostis epigejos, Deschampsia flexuosa, and (2) small shrubs with mainly Rubus fruticosus and R. idaeus—on clear cuts on two sites was studied for 2 years. Half the sample saplings were released from competing vegetation by repeated herbicide applications. This treatment significantly raised the diameter increment in both species at the site with higher competition intensity, and more strongly after the removal of small shrubs than after the removal of grasses. Sapling length increment was not significantly affected. After being released from small shrubs, saplings of both species developed a smaller specific fine root length (cm g⁻¹ fine root biomass) than unreleased saplings during the second year which was characterized by low rainfall. Root nitrogen concentration significantly increased after weed control in both vegetation types. Sapling foliar content of main nutritional elements was negatively related to dry mass and total chemical content of surrounding ground vegetation. Based on these results, a release from ground vegetation could be a useful tool to improve growth of planted beech and Douglas-fir saplings on sites with well-developed small shrubs competition (mainly by Rubus fruticosus and R. idaeus), or under fairly dry conditions.     

Ecophysiological and genetic variation in seedling traits and in first-year field performance of eight <Emphasis Type="Italic">Acacia senegal</Emphasis> provenances in the Blue Nile,Sudan

The genetic variation in seed weight, seed number per kg and seedling traits was compared among eight Acacia senegal provenances originating from the clay plain (east) and sand plains (west) of the gum belt in Sudan. The main objective of this study was to identify germplasm sources of A. senegal that have a good seed germination capacity and seedling traits suitable for reforestation in the clay-soil part of the dryland gum belt in the Blue Nile region in Sudan. A specific objective was to tentatively explore the adaptive strategy of A. senegal populations. Seventeen-week-old seedlings were planted in the field at spacing of 3 m × 3 m, giving 100 trees per plot and replication; within a randomized complete block design with four replications. The experimental site was in the clay plain region. Seed variables showed significant differences. Clay plain provenances showed considerable variation in seed weight and seed number. They had the smallest seed weight but the highest seed number, while the sand (western) provenances had the largest seed weight but lowest seed number. Seedling branch number, root length, root to shoot ratio and shoot dry weight differed significantly among the provenances 12 weeks after germination. Clay provenances had the highest branch number and shoot dry weight but the shortest roots and lowest root to shoot ratio. This was interpreted as showing better adaptation to the site in these local provenances in comparison to those originating from the western sandy soil regions. High positive correlations were observed between seedling variables, such as root nodule and branch numbers; this could be used for early selection. The variation was greater between provenance groups than within them, suggesting that especially selection among groups would yield genetic gain.     

Spatial pattern and regeneration dynamics in a temperate Abies–Tsuga forest in southwestern Japan

This article reports the regeneration dynamics of a temperate Abies–Tsuga forest in Kirishima Yaku National Park, southwestern Japan, and examines the influence of species coexistence mediated by gap disturbances on biomass production. All trees taller than 2 m in a 1-ha plot were monitored over four growing seasons. Three growth-form groups occupied different vertical layers. Evergreen conifers and deciduous broad-leaved trees tended to be spatially segregated from evergreen broad-leaved trees, which formed thickets in the understorey. The regeneration of understorey evergreen broad-leaved trees was affected by canopy gaps. The recruitment of conifers and deciduous broad-leaved species was not observed during the four growing seasons. This suggests that regeneration is sporadic and the present environmental conditions are not favorable for these canopy species. The mortality and unsuccessful recruitment of conifers and deciduous trees appeared to cause fluctuations in the productivity of the stand. However, an abundance of canopy gaps accelerates the regrowth of shorter species, and the fluctuation of productivity resulting from the population dynamics of canopy species would be partly mitigated by the regeneration of evergreen understorey species. The horizontal and vertical heterogeneity of the temperate mixed forest was a result of the patch structures of the three growth-form groups. The different regeneration patterns among the three groups, which were driven by interactions of species-specific regeneration niches and disturbance regimes, might be an important factor in maintaining the aboveground productivity in a transitional mixed forest between warm-temperate and cool-temperate zones.     

Foliar Responses of Understorey Abies lasiocarpa to Different Degrees of Release Cutting in a Betula papyrifera and Conifer Mixed Species Stand

Foliar responses of subalpine fir [Abies lasiocarpa (Hook.) Nutt.] to thinning were studied in a 35-yr-old mixed stand of paper birch (Betula papyrifera Marsh.) and conifers. The stand regenerated naturally after a wildfire with a canopy dominated by paper birch (average height 9.8 m) and an understorey dominated by subalpine fir (average height 1.6 m). The stand was thinned to four densities of birch: 0, 600 and 1200 stems ha-¹ and control (unthinned at 2300-6400 stems ha-¹) in the autumn of 1995. The understorey conifers, mainly subalpine fir, were thinned to 1200 stems ha-¹. The study used a completely randomized split-plot design. Three sample trees were systematically selected from each treatment replicate and each tree stratum (upper, intermediate and lower understorey). One-year-old and older age class needles were collected from one south-facing branch within the fifth whorl from the tree top. Thinning of paper birch significantly (p <0.001) increased leaf area and dry weight per 100 needles for intermediate and short trees except in the 0 birch treatment. Understorey subalpine fir trees in 600 stems ha¹ birch (T3) had the largest leaf area and leaf dry weight per 100 1-yr-old needles. Specific leaf area (SLA) decreased from unthinned (T1) to 0 birch (T4). Lower understorey trees had the largest SLA. One-year-old needles had significantly higher N, P and K concentrations in all the thinning treatments. These responses are consistent with the shade tolerance of subalpine fir. The results suggest that when managing a paper birch-conifers mixed-wood forest it may be of benefit to understorey conifers to leave a birch canopy as a nursing crop.     

Weed biomass dynamics in planted fallow systems in the humid forest zone of southern Cameroon

Interest in planted fallow systems has focused on soil fertility improvement, neglecting other potential benefits of such systems. It is important to quantify other processes responsible for crop yield increases under planted fallows, such as weed control. The suppressive potential on weeds of Flemingia macrophylla [(Willd.) Merrill] and Pueraria phaseoloides (Roxb.) Benth, planted fallows was evaluated in field trials in three villages in southern Cameroon. In each village, experiments were set up in 4–5 year-old bush fallow dominated by Chromolaena odorata (L.) R. M. King & H. Rob. and 20 year-old secondary forest. Total aboveground biomass production of P. phaseoloides was 7.45 Mg ha⁻¹, 4.2 times higher than F. macrophylla (1.78 Mg ha⁻¹ ; P < 0.05). The high biomass of P. phaseoloides resulted in a significantly greater reduction in total weed biomass compared to Flemingia macrophylla in both wet and dry seasons. In the wet season (11 and 18 MAP), there were significant fallow system × land use and fallow system × village interactions for total weeds and broadleaf weeds. P. phaseoloides in bush (0.55 Mg ha⁻¹), and P. phaseoloides at Ngoumou (0.09 Mg ha⁻¹) had the lowest total weeds in the wet seasons. After the dry season, the lowest total weed mass was consistently recorded in P. phaseoloides while the highest was in the natural regrowth. The population of grasses was always higher in the F. macrophylla system than in P. phaseoloides system throughout the wet and dry seasons. Grass biomass in the P. phaseoloides-forest LUS was the least (0.01 Mg ha⁻¹), 58 times lower than in F. macrophylla-bush (0.58 Mg ha⁻¹). Biomass production of P. phaseoloides was highly significantly correlated with total weed biomass (r = −0.64; P = 0.004) while no relationship was found between biomass production of F. macrophylla and total weed biomass (r = −0.08, P = 0.747). It was concluded that P. phaseoloides was a suitable leguminous species for weed control. But for F. macrophylla, its low biomass production coupled with a compact plant architecture compromised it as an appropriate species for weed control in a planted fallow system.     

Performance of loblolly pine (Pinus taeda L.) seedlings and micropropagated plantlets on an east Texas site: I. Above- and belowground growth

East Texas contains the western extent of the natural range of loblolly pine (Pinus taeda L.) and, therefore, many planted seedlings there experience water deficit sometimes leading to plantation failure. One solution may be to regenerate with clonally propagated drought-hardy planting stock. The objective of this research was to compare the field performance of loblolly pine seedlings and plantlets of diverse genetic origin, produced via micropropagation technology.Two adjacent sites were established (Site I in 1993 and Site II in 1994) with trees produced from four genetic families: Liberty (LIB) and Montgomery (MON) Counties from southeast Texas, and Fayette (FAY) and Bastrop (BAS) Counties from the “Lost Pines” in Central Texas. Height, groundline diameter (GLD), leaf area, survival, root/shoot ratio, and root system architecture were measured throughout the 1994 and 1995 growing seasons. In addition, height and diameter at breast height on Site II were measured at the end of 1999 and 2000 growing seasons.Height and GLD growth for seedlings was significantly greater than for plantlets on both sites. However, mean relative growth rates for height were greater for plantlets during the first growing season, but comparable thereafter. Survival for all treatments was >85% on Site I and >90% on Site II at the end of the 1995 growing season. Survival was significantly different, but by a negligible margin, between families and stock types on Site II at the end of the 1995 growing season, and by a margin of 7% (89% for seedlings vs. 82% for plantlets) at the end of the 2000 growing season. Seedlings had greater leaf area growth than plantlets after two growing seasons. Root/shoot ratio was significantly greater for plantlets after two growing seasons, whereas their specific root length was significantly smaller than that of seedlings. This was attributed to root system architecture. Whereas plantlets produced thicker roots with less length per unit dry weight, seedlings produced more branching with thinner roots for similar dry weights.     

Effects of nurse shrubs and tree shelters on the survival and growth of two Austrocedrus chilensis seedling types in a forest restoration trial in semiarid Patagonia, Argentina

? Context

Harsh environmental conditions in xeric sites of Andean Patagonia, affect the emergence, survival, and growth of either naturally grown or planted Austrocedrus seedlings.

? Aims

We evaluated the effects of nurse shrubs and tree shelters on the survival and growth of Austrocedrus seedlings as compared to unprotected (control) areas and how differently produced seedling types perform under these treatments.

? Methods

In 2006, two Austrocedrus seedling types (1?+?2?=?S1 and Plug 2?+?1?=?S2) were planted under shrub cover (C1), tree shelter (C2), and control (C3). Soil surface temperature and moisture were measured for each treatment during the first growing season, while seedling survival and height were recorded during 5 years.

? Results

Survival was not affected by cover type the first year, but it was affected by seedling type (S1?>?S2). After an extremely dry second growing season, seedling survival significantly decreased in relation to either cover or seedling type. Five years after plantation, survival was significantly higher for C1 and C2 (40?C60 %) as compared to C3-S2 (18 %). Seedling height was significantly affected by cover, but not by seedling type.

? Conclusions

The use of nurse shrubs and/or tree shelters is useful in Austrocedrus seedling restoration trials. Seedling morphology appears as relevant for survival in semiarid environments.     

Response of Fagus sylvatica Seedlings to Root Trenching of Overstorey Picea abies

In a trenching experiment the impact of root competition by overstorey Norway spruce on growth and allocation of above-ground woody biomass of advanced planted beech was investigated in two stands over two growing seasons after trenching. Measurements of soil water potential were taken inside and outside trenched areas by tensiometers at 16 measuring points in one stand from May to September 1999. Height and diameter of the seedlings, as well as branch length and diameter, were measured of beech growing in trenched and untrenched conditions in September before trenching (1998) and afterwards (1999 and 2000). Tensiometers inside the trenches reached the expiring value of -0.085 Mpa 30-40 days later, or never, compared with those in untrenched areas. Whereas relative growth rate (RGR) in height was not affected by trenching, RGR both in diameter and in estimated dry weight of the main stem were substantially enhanced in the first growing season after trenching (1999). A different result was obtained in 2000, when RGR in seedling diameter and estimated dry weight of the main stem was slightly reduced by trenching. The only variable that showed increased RGR of the trenched seedlings in both years was the estimated dry weight of the branches, indicating different above-ground biomass allocation patterns of seedlings with and without root competition.     

Grass interference limits resource availability and reduces growth of juvenile red pine in the field

The effects of competing grasses on resource availability, growth and ecophysiological characteristics of 3-0 red pine (Pinus resinosa Ait.) seedlings were examined the first two years following outplanting in Anoka County, Minnesota, USA. Equal numbers of seedlings were planted into suppressed and undisturbed grass communities in a sandy soil. Grass suppression was maintained throughout the first growing season, but partially discontinued thereafter on the site. During the first field season interference from grass reduced pine seedling root collar diameter, needle length, number of new root tips, and lateral root length by over 40%. Mean pre-dawn needle water potential was 0.55 MPa lower in undisturbed grass plots during a brief drought in year one, but otherwise water stress was not significantly (p=0.05) influenced by grass interference. The presence of grass also reduced, up to 50%, the photosynthetically active radiation reaching the seedling canopy. At the end of year one, total biomass N, P, K, and Ca content were significantly (p=0.05) less in seedlings growing in the undisturbed grass community. Nitrogen was deficient in seedlings growing in grass. After two growing seasons, seedling shoot length (p=0.03), root collar diameter (p=0.001), and needle length (p=0.001) were significantly less (40, 54 and 20%, respectively) for seedlings growing in undisturbed grass. Seedling growth reductions induced by grass competition were associated with multiple environmental stressors in the field and not restricted to water stress as was observed in earlier studies with pine species at low and mid-latitude sites.     

Root Egress and Field Performance of Actively Growing Betula pendula Container Seedlings

The objective of this study was to evaluate the possibility of enlarging the planting window of container-grown silver birch seedlings from spring and autumn to summer by planting young, actively growing seedlings. For over 3 yrs the study investigated the growth, survival and damage of silver birch seedlings grown in containers and planted at different times during the growing season on 18 sites in fields and forest sites in central Finland. In a pot experiment in the greenhouse, the root-egress ability of seedlings planted at different times during the growing season was monitored. Root egress of seedlings was rapid from the beginning of July to the middle of August. Actively growing seedlings planted in summer on a site suitable for silver birch grew and survived at least as well as seedlings planted in spring during the dormant stage. The risk of drought stress increased when seedlings were planted on easily drying, coarse sandy soils. The risk was also high in soils with high levels of fine soil fractions that become hard when dry and when the dry period continued for several weeks before planting. In conclusion, it is possible to enlarge the planting window of birch seedlings to July and the beginning of August by using actively growing container seedlings.     

Effect of support on the growth of a woody vine,Wisteria floribunda DC. (Leguminosae)

Seedling ofWisteria floribunda, which belongs to the twiner type of climbing plants, were planted in nursery and the effect of support on the growth of the seedlings was tested. The seedlings were grown with 240 cm-height and 120 cm-height supports (the culms of a dwarf bamboo), and without support. Positive effect of the supports and its length were observed for stem length ofW. floribunda at the end of the growing season. The positive effect of support was also observed for total dry weight. Total dry weight with 240 cm-height support reached more than the double of the seedlings without support. These effects of the support were attributed to die-back behavior of the twining stem, which detached from the support or did not encounter the support. Diameter of the stems without support showed a rapid decrease toward the stem tip, while that with support were relatively constant when they were twining around the support. The existence of the support also affected the dry matter allocation in this species; supported seedlings allocated larger proportion of biomass to current-year stems than unsupported seedlings, although the allocation to the roots was smaller in the supported treatments. Support availability may be critical for the establishment and further growth of the seedlings ofW. floribunda which regenerate at the forest edge and canopy gaps. A part of this report was presented at the 107th Annual Meeting of the Japanese Forestry Society, at Tsukuba, April, 1996.     

Vegetation structure influences the vertical stratification of open- and edge-space aerial-foraging bats in harvested forests

Heavy logging leads to regrowth of dense forest, which may adversely affect the flight and foraging activities of bats. We compared insectivorous bat activity and insect abundance at three heights (understorey, subcanopy and canopy), two locations (forest and track) and three time periods (evening, night and dawn), in old and young regrowth sites in south-eastern Australia (456 detector-hours). We measured activity levels of all bats and four echolocation guilds—one open-space and three edge-space aerial-foraging guilds. Mean bat activity in the subcanopy and canopy was up to 11 times that in the understorey of forests, a pattern opposite to that of insect abundance. However, bat activity in the two upper strata was lower in young regrowth than in old regrowth. Vegetation was more cluttered in young regrowth at these upper heights (closer stems and less vertical space in the subcanopy). Mean activity on the track was 2–5 times higher than in the forest, particularly at understorey level (17 times higher for all bats), where vegetation was less cluttered (more distant understorey trees and shrubs, and less cover of ground vegetation). Time of night had little effect on bat activity. The negative response of bat guilds to increased clutter was strongest in the open-space guild and weakest in the edge-space guild with the highest frequency calls. There was an interaction between insect abundance and an index of vegetation openness, with high values of both variables producing high bat activity levels for all bats and the two highest frequency call guilds. Our results highlight the need for management practices in logged forests that increase or preserve the amount of flight and foraging space available to bats.     

Understorey fuel load estimation along two post-fire chronosequences of Pinus halepensis Mill. forests in Central Greece

Pinus halepensis forests are among the forest ecosystems in the Mediterranean Basin most affected by fire. Their distribution across lowland areas, in particular along the wildland–urban interface, increases the need to understand their ecology and responses to fire regime for their effective management. Apart from the extremely flammable tree layer, in several stands of these forests there is an increased fuel load attributed to the well-developed understorey of evergreen sclerophyllous shrubs. Taking into consideration that, in contrast with the long period required for full development of post-fire-regenerating pines, these shrubs resprout vigorously within the first post-fire weeks, it is important to explore the temporal trend of fuel accumulation to determine the risk of a second fire across a burned landscape. Two post-fire chronosequences of, in total, 12 P. halepensis stands were considered for sampling in Central Greece. The first chronosequence corresponds to pine stands characterized by the dominance of evergreen sclerophyllous shrubs in the understorey (Type 1) whereas the second chronosequence corresponds to pine stands where the cover of such shrubs was lower (Type 2). This study helps in understanding the fuel dynamics according to the type of P. halepensis forest stand and to anticipate future biomass growth. The proposed equations are simple tools, enabling land managers to estimate understorey total fuel load easily by visually recording the cover and height of the evergreen sclerophyllous shrub component, to justify understorey fuel reduction measures.     

Tree seedling survival and growth in logged and undisturbed seasonal deciduous forest fragments in central Brazil

We evaluated the survival and growth of Amburana cearensis, Cedrela fissilis, and Sterculia striata seedlings in three seasonally tropical dry forest fragments that were subjected to different logging levels (intact, intermediately and heavily logged). In each fragment, we planted 40 seedlings of each species and monitored these over a period of 1 year. The highest seedling survival rate (64%) occurred in the heavily logged fragment, which, however, also had the highest mortality risk for all species during the dry season. Only S. striata seedlings had different survival rates among the fragments. Height and diameter growth were higher at sites with higher canopy openness in the wet season. The survival and growth rates of seedlings planted in logged fragments indicate that this technique can be applied to restore and enrich logged forests of the Paran? River Basin.     

Estimating fuelwood production and yield in regrowth dry miombo woodland in Zambia

A combination of destructive and non-destructive samples was used to develop regression models for estimating fuelwood production and yield in regrowth dry miombo stands aged 6–34 years. Fuelwood yield from understorey species was estimated from girth at stump height (gsh) data while gsh and stem height data were necessary for estimating yield from canopy species. Mean fuelwood production was estimated at 1.93 m³ ha⁻¹ year⁻¹. It was found that canopy species had a greater sustained stem growth than understorey species. Enhancement of regeneration of canopy species is therefore recommended for the management of miombo woodland for fuelwood production.     

Interactions among cutting frequency, reserve carbohydrates, and post-cutting biomass production in Gliricidia sepium and Leucaena leucocephala

The ability of trees and shrubs to coppice vigorously after being cut or pruned is of great importance in the management of agroforestry systems. In a study conducted in the seasonally dry climate of Ibadan, Nigeria, frequent cutting progressively decreased concentrations of starch and total reserve carbohydrates in Gliricidia sepium (Jacq.) Walp. and Leucaena leucocephala (Lam.) De Wit. In frequently cut trees, starch was severely reduced in the stumps of both species. In contrast, soluble sugar concentrations in roots and stems of both species were consistently maintained at or above the levels in uncut control trees, suggesting that sugar levels were maintained through the hydrolysis of starch reserves. No starch replenishment occurred during the six weeks after cutting. In trees that were cut and then allowed to grow undisturbed during the wet season, replenishment of stem starch began within three months after cutting. Shoot regrowth after cutting decreased starch levels first in stems and, only after additional cuts, in roots. Dry-season cuts had little effect on reserve carbohydrates in G. sepium but quickly reduced stem starch in L. leucocephala. Frequent cutting decreased dry matter production, and this decrease was correlated with reduced levels of reserve carbohydrates.This revised version was published online in November 2005 with corrections to the Cover Date.