:Leaf litter is an important source of nutrients to tropical forest trees, but its importance for... more :Leaf litter is an important source of nutrients to tropical forest trees, but its importance for understorey seedling growth is not well understood. Seedlings of Licania platypus (n = 190) and Coussarea curvigemmia (n = 304) were transplanted into deeply shaded forest plots in Panama having received 2 y of litter addition or removal and 7 y of fertilization with nitrogen, phosphorus and potassium combined, and their growth and foliar nutrients measured after 13 and 6 mo respectively. Licania platypus growing in litter addition and removal plots had faster height growth and slower leaf growth respectively than in control plots; C. curvigemmia showed no significant effects apart from lower survival in litter addition plots. These effects may be driven by soil nutrients, as suggested by differences in foliar nitrogen and potassium (but not phosphorus) concentrations, and by a pot experiment in a shadehouse using Ochroma pyramidale seedlings, which showed higher leaf area in soils from litter-addition plots, although seedling dry weight was higher only in fertilized soils. Overall, these results show that for one of two species, understorey seedling growth was increased by 2 y of doubled litterfall, and thus that they were probably nutrient limited even in the relatively fertile soils of this semi-deciduous tropical forest.
ABSTRACTHurricane Gilbert caused disturbance to Jamaican montane rainforests in 1988. This study ... more ABSTRACTHurricane Gilbert caused disturbance to Jamaican montane rainforests in 1988. This study provides a detailed characterization of landscape-level changes in light below the canopy of these forests after the hurricane. Hemispherical photographs were taken below the forest canopy at four sites at permanent points 1 m above the ground between 7 and 33 mo after the hurricane. For each photograph photosynthetically active radiation (PAR) was computed. PAR declined exponentially in all sites during the period of measurement. During the first 24 mo after the hurricane, PAR beneath the canopy was significantly greater in sites that had been defoliated during the hurricane than in sites where few trees had been defoliated. By 28 mo after the hurricane there was no significant difference in PAR beneath the canopy among the four sites. By 33 mo after the hurricane canopy recovery was nearly complete and PAR was only slightly higher than measurements made before the hurricane. Our result...
1 Forests in the Blue Mountains of Jamaica were damaged by Hurricane Gilbert which passed over th... more 1 Forests in the Blue Mountains of Jamaica were damaged by Hurricane Gilbert which passed over the island on 12 September 1988. 2 In plots between 1300-1900 m, recorded 5-41 months after the hurricane, most stems (61.4% of 4949 living stems) and most species (44 of 47 common species) had sprouts. Comparing species, percent of stems sprouting ranged from 0 to 100%. 3 Broken stems sprouted proportionately more than intact stems; completely defoliated stems sprouted proportionately more than those not completely defoliated; there was no difference between uprooted and upright stems; and stems > 10 cm d.b.h. sprouted more frequently and produced more sprouts per stem, than those 30 sprouting stems, four sprouted more from below 2.5 m, five more from above 2.5 m and five had sprouts evenly distributed. For all species combined, approximately equal numbers of stems fell into each of these three categories. 6 Survivorship up to 41 months after the hurricane was higher in stems with sprouts than those without. 7 There was no simple relationship between the frequency of sprouting of species and microenvironments where seed germination and seedling establishment have been recorded. However, eight common species which have rarely been observed to germinate or establish (in a wide range of conditions) had high frequencies of sprouting. We propose that sprouting is an important mechanism by which many species maintain their presence in these forests.
... Key words: drought resistance; Jamaica; leaf xeromorphy; sclerophyll; tropical montane forest... more ... Key words: drought resistance; Jamaica; leaf xeromorphy; sclerophyll; tropical montane forest; water potential; water relationships. ... TROPICAL MONTANE FOREST WATER RELATIONS TABLE 1. The enyironmental availability of water during the studies of plant water relations. ...
... 2562-2580 ? 1995 by the Ecological Society of America DAMAGE AND RESPONSIVENESS OF JAMAICAN M... more ... 2562-2580 ? 1995 by the Ecological Society of America DAMAGE AND RESPONSIVENESS OF JAMAICAN MONTANE TREE SPECIES AFTER DISTURBANCE BY A HURRICANE1 ... Abstract. A severe hurricane affected Jamaican montane rain forests in 1988. ...
... NITROGEN AND PHOSPHORUS FERTILIZATION EFFECTS ON VENEZUELAN MONTANEFOREST TRUNK GROWTH AND LI... more ... NITROGEN AND PHOSPHORUS FERTILIZATION EFFECTS ON VENEZUELAN MONTANEFOREST TRUNK GROWTH AND LITTERFALL1 ... Abstract. In a montane rain forest at -2500 m in Venezuela we fertilized plots with N, with P, or with N and P for 4.5 yr. ...
To determine if there were consistent differences in growth, mortality, and recruitment on slopes... more To determine if there were consistent differences in growth, mortality, and recruitment on slopes and ridge crests in tropical montane forests, which could explain the (frequent but not universal) low stature of trees in the ridgetop forests, we analyzed data from long-term plots in Jamaica (1990–1994; sixteen 200-m2 plots, six on ridge crests and five each on north and south slopes). Mortality was higher on north slopes, while growth and recruitment rates were not significantly different among positions. Soil pH and effects of recent disturbance by Hurricane Gilbert were positively correlated with growth and recruitment, while slope angle and disturbance effects were the best predictors of mortality. The patterns we found in Jamaica, that growth and recruitment were not higher on ridge crests than slopes, are different than those found by Herwitz and Young in Australia where growth and turnover were greater on a ridge crest. Therefore, it is not possible at present to make simple generalizations about dynamics of ridge crest versus slope forests in the montane tropics.
:Leaf litter is an important source of nutrients to tropical forest trees, but its importance for... more :Leaf litter is an important source of nutrients to tropical forest trees, but its importance for understorey seedling growth is not well understood. Seedlings of Licania platypus (n = 190) and Coussarea curvigemmia (n = 304) were transplanted into deeply shaded forest plots in Panama having received 2 y of litter addition or removal and 7 y of fertilization with nitrogen, phosphorus and potassium combined, and their growth and foliar nutrients measured after 13 and 6 mo respectively. Licania platypus growing in litter addition and removal plots had faster height growth and slower leaf growth respectively than in control plots; C. curvigemmia showed no significant effects apart from lower survival in litter addition plots. These effects may be driven by soil nutrients, as suggested by differences in foliar nitrogen and potassium (but not phosphorus) concentrations, and by a pot experiment in a shadehouse using Ochroma pyramidale seedlings, which showed higher leaf area in soils from litter-addition plots, although seedling dry weight was higher only in fertilized soils. Overall, these results show that for one of two species, understorey seedling growth was increased by 2 y of doubled litterfall, and thus that they were probably nutrient limited even in the relatively fertile soils of this semi-deciduous tropical forest.
ABSTRACTHurricane Gilbert caused disturbance to Jamaican montane rainforests in 1988. This study ... more ABSTRACTHurricane Gilbert caused disturbance to Jamaican montane rainforests in 1988. This study provides a detailed characterization of landscape-level changes in light below the canopy of these forests after the hurricane. Hemispherical photographs were taken below the forest canopy at four sites at permanent points 1 m above the ground between 7 and 33 mo after the hurricane. For each photograph photosynthetically active radiation (PAR) was computed. PAR declined exponentially in all sites during the period of measurement. During the first 24 mo after the hurricane, PAR beneath the canopy was significantly greater in sites that had been defoliated during the hurricane than in sites where few trees had been defoliated. By 28 mo after the hurricane there was no significant difference in PAR beneath the canopy among the four sites. By 33 mo after the hurricane canopy recovery was nearly complete and PAR was only slightly higher than measurements made before the hurricane. Our result...
1 Forests in the Blue Mountains of Jamaica were damaged by Hurricane Gilbert which passed over th... more 1 Forests in the Blue Mountains of Jamaica were damaged by Hurricane Gilbert which passed over the island on 12 September 1988. 2 In plots between 1300-1900 m, recorded 5-41 months after the hurricane, most stems (61.4% of 4949 living stems) and most species (44 of 47 common species) had sprouts. Comparing species, percent of stems sprouting ranged from 0 to 100%. 3 Broken stems sprouted proportionately more than intact stems; completely defoliated stems sprouted proportionately more than those not completely defoliated; there was no difference between uprooted and upright stems; and stems > 10 cm d.b.h. sprouted more frequently and produced more sprouts per stem, than those 30 sprouting stems, four sprouted more from below 2.5 m, five more from above 2.5 m and five had sprouts evenly distributed. For all species combined, approximately equal numbers of stems fell into each of these three categories. 6 Survivorship up to 41 months after the hurricane was higher in stems with sprouts than those without. 7 There was no simple relationship between the frequency of sprouting of species and microenvironments where seed germination and seedling establishment have been recorded. However, eight common species which have rarely been observed to germinate or establish (in a wide range of conditions) had high frequencies of sprouting. We propose that sprouting is an important mechanism by which many species maintain their presence in these forests.
... Key words: drought resistance; Jamaica; leaf xeromorphy; sclerophyll; tropical montane forest... more ... Key words: drought resistance; Jamaica; leaf xeromorphy; sclerophyll; tropical montane forest; water potential; water relationships. ... TROPICAL MONTANE FOREST WATER RELATIONS TABLE 1. The enyironmental availability of water during the studies of plant water relations. ...
... 2562-2580 ? 1995 by the Ecological Society of America DAMAGE AND RESPONSIVENESS OF JAMAICAN M... more ... 2562-2580 ? 1995 by the Ecological Society of America DAMAGE AND RESPONSIVENESS OF JAMAICAN MONTANE TREE SPECIES AFTER DISTURBANCE BY A HURRICANE1 ... Abstract. A severe hurricane affected Jamaican montane rain forests in 1988. ...
... NITROGEN AND PHOSPHORUS FERTILIZATION EFFECTS ON VENEZUELAN MONTANEFOREST TRUNK GROWTH AND LI... more ... NITROGEN AND PHOSPHORUS FERTILIZATION EFFECTS ON VENEZUELAN MONTANEFOREST TRUNK GROWTH AND LITTERFALL1 ... Abstract. In a montane rain forest at -2500 m in Venezuela we fertilized plots with N, with P, or with N and P for 4.5 yr. ...
To determine if there were consistent differences in growth, mortality, and recruitment on slopes... more To determine if there were consistent differences in growth, mortality, and recruitment on slopes and ridge crests in tropical montane forests, which could explain the (frequent but not universal) low stature of trees in the ridgetop forests, we analyzed data from long-term plots in Jamaica (1990–1994; sixteen 200-m2 plots, six on ridge crests and five each on north and south slopes). Mortality was higher on north slopes, while growth and recruitment rates were not significantly different among positions. Soil pH and effects of recent disturbance by Hurricane Gilbert were positively correlated with growth and recruitment, while slope angle and disturbance effects were the best predictors of mortality. The patterns we found in Jamaica, that growth and recruitment were not higher on ridge crests than slopes, are different than those found by Herwitz and Young in Australia where growth and turnover were greater on a ridge crest. Therefore, it is not possible at present to make simple generalizations about dynamics of ridge crest versus slope forests in the montane tropics.
Uploads
Papers