The Experts below are selected from a list of 6006 Experts worldwide ranked by ideXlab platform
Christopher H. Lusk - One of the best experts on this subject based on the ideXlab platform.
-
trade offs in juvenile growth potential vs Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2016Co-Authors: Christopher H. Lusk, Kerrie M. Sendall, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
-
Trade‐offs in juvenile growth potential vs. Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2015Co-Authors: Kerrie M. Sendall, Christopher H. Lusk, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
-
a conifer angiosperm divergence in the growth vs Shade Tolerance trade off underlies the dynamics of a new zealand warm temperate rain forest
Journal of Ecology, 2015Co-Authors: Christopher H. Lusk, Murray A. Jorgensen, Peter J. BellinghamAbstract:Summary A central tenet of forest ecology is that succession and regeneration dynamics are driven by an interspecific trade-off between juvenile growth rates in high light and Shade Tolerance. There is evidence, however, that a single trade-off axis may fail to explain the dynamics of mixed conifer–angiosperm rain forests in the Southern Hemisphere, especially in New Zealand. We tested for growth vs. Shade Tolerance trade-offs by measuring juvenile growth of five podocarps and five broadleaved canopy angiosperms across a wide range of light environments in a New Zealand warm-temperate rain forest. The light compensation point of growth was used as a measure of species light requirements, which we then compared with height growth in 10% light, approximating the environments encountered beneath small treefall gaps. Despite considerable overlap between the ranges of both growth rates and compensation points found in the two lineages, major axis tests showed that the growth vs. Shade Tolerance trade-off differed significantly between podocarp and angiosperm species. At a common compensation point, angiosperms were faster growing than podocarps in 10% light. However, juveniles of these angiosperm species were notably scarce in the more open environments associated with forest margins. Synthesis. A conifer–angiosperm divergence in the growth vs. Shade Tolerance trade-off may explain long-standing problems of the dynamics of these forests. Although juveniles of most lowland podocarps can tolerate considerable Shade, the more vigorous response of broadleaved angiosperms to small canopy openings enables them to out-compete podocarps in old-growth stands. The greater abundance of podocarp juveniles on forest margins cannot be attributed to them out-competing angiosperm species where light is abundant and is likely to reflect superior resistance to frost and/or drought. The drivers of the dynamics of New Zealand's podocarp–broadleaved forests therefore differ appreciably from those ascribed to tropical and north-temperate forests.
-
A conifer–angiosperm divergence in the growth vs. Shade Tolerance trade‐off underlies the dynamics of a New Zealand warm‐temperate rain forest
Journal of Ecology, 2015Co-Authors: Christopher H. Lusk, Murray A. Jorgensen, Peter J. BellinghamAbstract:Summary A central tenet of forest ecology is that succession and regeneration dynamics are driven by an interspecific trade-off between juvenile growth rates in high light and Shade Tolerance. There is evidence, however, that a single trade-off axis may fail to explain the dynamics of mixed conifer–angiosperm rain forests in the Southern Hemisphere, especially in New Zealand. We tested for growth vs. Shade Tolerance trade-offs by measuring juvenile growth of five podocarps and five broadleaved canopy angiosperms across a wide range of light environments in a New Zealand warm-temperate rain forest. The light compensation point of growth was used as a measure of species light requirements, which we then compared with height growth in 10% light, approximating the environments encountered beneath small treefall gaps. Despite considerable overlap between the ranges of both growth rates and compensation points found in the two lineages, major axis tests showed that the growth vs. Shade Tolerance trade-off differed significantly between podocarp and angiosperm species. At a common compensation point, angiosperms were faster growing than podocarps in 10% light. However, juveniles of these angiosperm species were notably scarce in the more open environments associated with forest margins. Synthesis. A conifer–angiosperm divergence in the growth vs. Shade Tolerance trade-off may explain long-standing problems of the dynamics of these forests. Although juveniles of most lowland podocarps can tolerate considerable Shade, the more vigorous response of broadleaved angiosperms to small canopy openings enables them to out-compete podocarps in old-growth stands. The greater abundance of podocarp juveniles on forest margins cannot be attributed to them out-competing angiosperm species where light is abundant and is likely to reflect superior resistance to frost and/or drought. The drivers of the dynamics of New Zealand's podocarp–broadleaved forests therefore differ appreciably from those ascribed to tropical and north-temperate forests.
-
Ontogeny, understorey light interception and simulated carbon gain of juvenile rainforest evergreens differing in Shade Tolerance.
Annals of botany, 2011Co-Authors: Christopher H. Lusk, Manuel Matías Pérez-millaqueo, Frida I. Piper, Alfredo SaldañaAbstract:BACKGROUND AND AIMS A long-running debate centres on whether Shade Tolerance of tree seedlings is mainly a function of traits maximizing net carbon gain in low light, or of traits minimizing carbon loss. To test these alternatives, leaf display, light-interception efficiency, and simulated net daily carbon gain of juvenile temperate evergreens of differing Shade Tolerance were measured, and how these variables are influenced by ontogeny was queried. METHODS The biomass distribution of juveniles (17-740 mm tall) of seven temperate rainforest evergreens growing in low (approx. 4 %) light in the understorey of a second-growth stand was quantified. Daytime and night-time gas exchange rates of leaves were also determined, and crown architecture was recorded digitally. YPLANT was used to model light interception and carbon gain. RESULTS An index of species Shade Tolerance correlated closely with photosynthetic capacities and respiration rates per unit mass of leaves, but only weakly with respiration per unit area. Accumulation of many leaf cohorts by Shade-tolerant species meant that their ratios of foliage area to biomass (LAR) decreased more gradually with ontogeny than those of light-demanders, but also increased self-shading; this depressed the foliage silhouette-to-area ratio (STAR), which was used as an index of light-interception efficiency. As a result, displayed leaf area ratio (LAR(d) = LAR × STAR) of large seedlings was not related to species Shade Tolerance. Self-shading also caused simulated net daily carbon assimilation rates of Shade-tolerant species to decrease with ontogeny, leading to a negative correlation of Shade Tolerance with net daily carbon gain of large (500 mm tall) seedlings in the understorey. CONCLUSIONS The results suggest that efficiency of energy capture is not an important correlate of Shade Tolerance in temperate rainforest evergreens. Ontogenetic increases in self-shading largely nullify the potential carbon gain advantages expected to result from low respiration rates and long leaf lifespans in Shade-tolerant evergreens. The main advantage of their long-lived leaves is probably in reducing the costs of crown maintenance.
Peter B. Reich - One of the best experts on this subject based on the ideXlab platform.
-
trade offs in juvenile growth potential vs Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2016Co-Authors: Christopher H. Lusk, Kerrie M. Sendall, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
-
Trade‐offs in juvenile growth potential vs. Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2015Co-Authors: Kerrie M. Sendall, Christopher H. Lusk, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
Frida I. Piper - One of the best experts on this subject based on the ideXlab platform.
-
Patterns of carbon storage in relation to Shade Tolerance in southern South American species.
American journal of botany, 2015Co-Authors: Frida I. PiperAbstract:PREMISE OF THE STUDY Carbon (C) allocation to storage in woody tissues at the expense of growth is thought to promote Shade Tolerance, yet few studies on the subject examined C storage during maximum growth and considered stand influences. I asked how C storage in different plant tissues relates to Shade Tolerance in temperate forests with contrasting climates and physiognomies, and whether relationships vary during the growing season. METHODS In the late spring and late summer, I harvested seedlings of eight species with contrasting light requirements from the understory of a cold rainforest and a Mediterranean forest in Chile. Nonstructural carbohydrate (NSC) concentrations and pools (i.e., biomass x NSC concentration) were determined in leaves, aboveground wood, and roots. The effects of Shade Tolerance and sampling date on the NSCs were analyzed for each forest and tissue with linear mixed-effects models. KEY RESULTS In both forests, concentrations of NSC and soluble sugars in woody tissues, as well as fractions of NSC in these tissues, were lower in Shade tolerant than in Shade intolerant species. For root NSC concentrations, these trends depended on the sampling date: in the late spring the concentrations were similar in Shade tolerant and intolerant species, while in the late summer they were lower in Shade tolerant species. CONCLUSIONS Shade Tolerance is not linked to C storage in the two studied forests, suggesting that allocation to growth or defenses could be more advantageous for low light persistence. Alternatively, high levels of C storage could be also selected in Shade intolerant species to face herbivory or drought.
-
Ontogeny, understorey light interception and simulated carbon gain of juvenile rainforest evergreens differing in Shade Tolerance.
Annals of botany, 2011Co-Authors: Christopher H. Lusk, Manuel Matías Pérez-millaqueo, Frida I. Piper, Alfredo SaldañaAbstract:BACKGROUND AND AIMS A long-running debate centres on whether Shade Tolerance of tree seedlings is mainly a function of traits maximizing net carbon gain in low light, or of traits minimizing carbon loss. To test these alternatives, leaf display, light-interception efficiency, and simulated net daily carbon gain of juvenile temperate evergreens of differing Shade Tolerance were measured, and how these variables are influenced by ontogeny was queried. METHODS The biomass distribution of juveniles (17-740 mm tall) of seven temperate rainforest evergreens growing in low (approx. 4 %) light in the understorey of a second-growth stand was quantified. Daytime and night-time gas exchange rates of leaves were also determined, and crown architecture was recorded digitally. YPLANT was used to model light interception and carbon gain. RESULTS An index of species Shade Tolerance correlated closely with photosynthetic capacities and respiration rates per unit mass of leaves, but only weakly with respiration per unit area. Accumulation of many leaf cohorts by Shade-tolerant species meant that their ratios of foliage area to biomass (LAR) decreased more gradually with ontogeny than those of light-demanders, but also increased self-shading; this depressed the foliage silhouette-to-area ratio (STAR), which was used as an index of light-interception efficiency. As a result, displayed leaf area ratio (LAR(d) = LAR × STAR) of large seedlings was not related to species Shade Tolerance. Self-shading also caused simulated net daily carbon assimilation rates of Shade-tolerant species to decrease with ontogeny, leading to a negative correlation of Shade Tolerance with net daily carbon gain of large (500 mm tall) seedlings in the understorey. CONCLUSIONS The results suggest that efficiency of energy capture is not an important correlate of Shade Tolerance in temperate rainforest evergreens. Ontogenetic increases in self-shading largely nullify the potential carbon gain advantages expected to result from low respiration rates and long leaf lifespans in Shade-tolerant evergreens. The main advantage of their long-lived leaves is probably in reducing the costs of crown maintenance.
-
seedling size influences relationships of Shade Tolerance with carbohydrate storage patterns in a temperate rainforest
Functional Ecology, 2007Co-Authors: Christopher H. Lusk, Frida I. PiperAbstract:Summary 1Carbohydrate storage has been attributed an important role in the ability to tolerate Shade, yet empirical support for this idea has been patchy. We asked if carbohydrate-storage patterns of seedling evergreens in low light are correlated with variation in Shade Tolerance, and how these patterns change with seedling size. 2We measured biomass distribution and total non-structural carbohydrate (NSC) concentrations of leaves, stems and roots of two seedling size classes of six evergreens growing in a temperate rainforest understorey. Light requirements of the six species were quantified by calculating the 10th percentile of the distribution of established seedlings in relation to canopy openness. 3NSC averaged 14% of the dry mass of small seedlings (40–60 mm tall), and 22% of that of large seedlings (400–600 mm tall). This difference was entirely due to variation in starch reserves, which on average accounted for 60% of NSC in small seedlings and 84% in large seedlings. 4NSC concentrations of leaves and roots (but not stems) of large seedlings were negatively correlated with species’ Shade Tolerance, but no such pattern was found in small seedlings. Leaf NSC on an area basis was not related to species’ Shade Tolerance in either size class. 5Partitioning of the NSC pool between leaves, stems and roots of small seedlings was closely related to variation in Shade Tolerance. Small seedlings of Shade-tolerant species had a relatively low proportion of their NSC pool in leaves and a high proportion in roots. This is likely to ensure the retention of the greater part of the NSC pool even in the event of extensive defoliation, and the availability of reserves to replace lost leaves. In contrast, the large leaf-mass fraction of large seedlings of Shade-tolerant species (46–47% of biomass) meant that these plants had a large proportion of their NSC pool in foliage. 6Results suggest that, in Chilean rainforest evergreens, any adaptive relationship of carbohydrate storage with Shade Tolerance may be confined to young seedlings, involving interspecific variation in the partitioning of reserves between leaves and other organs, rather than especially high NSC concentrations in Shade-tolerant species.
-
Seedling size influences relationships of Shade Tolerance with carbohydrate‐storage patterns in a temperate rainforest
Functional Ecology, 2007Co-Authors: Christopher H. Lusk, Frida I. PiperAbstract:Summary 1Carbohydrate storage has been attributed an important role in the ability to tolerate Shade, yet empirical support for this idea has been patchy. We asked if carbohydrate-storage patterns of seedling evergreens in low light are correlated with variation in Shade Tolerance, and how these patterns change with seedling size. 2We measured biomass distribution and total non-structural carbohydrate (NSC) concentrations of leaves, stems and roots of two seedling size classes of six evergreens growing in a temperate rainforest understorey. Light requirements of the six species were quantified by calculating the 10th percentile of the distribution of established seedlings in relation to canopy openness. 3NSC averaged 14% of the dry mass of small seedlings (40–60 mm tall), and 22% of that of large seedlings (400–600 mm tall). This difference was entirely due to variation in starch reserves, which on average accounted for 60% of NSC in small seedlings and 84% in large seedlings. 4NSC concentrations of leaves and roots (but not stems) of large seedlings were negatively correlated with species’ Shade Tolerance, but no such pattern was found in small seedlings. Leaf NSC on an area basis was not related to species’ Shade Tolerance in either size class. 5Partitioning of the NSC pool between leaves, stems and roots of small seedlings was closely related to variation in Shade Tolerance. Small seedlings of Shade-tolerant species had a relatively low proportion of their NSC pool in leaves and a high proportion in roots. This is likely to ensure the retention of the greater part of the NSC pool even in the event of extensive defoliation, and the availability of reserves to replace lost leaves. In contrast, the large leaf-mass fraction of large seedlings of Shade-tolerant species (46–47% of biomass) meant that these plants had a large proportion of their NSC pool in foliage. 6Results suggest that, in Chilean rainforest evergreens, any adaptive relationship of carbohydrate storage with Shade Tolerance may be confined to young seedlings, involving interspecific variation in the partitioning of reserves between leaves and other organs, rather than especially high NSC concentrations in Shade-tolerant species.
Kerrie M. Sendall - One of the best experts on this subject based on the ideXlab platform.
-
trade offs in juvenile growth potential vs Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2016Co-Authors: Christopher H. Lusk, Kerrie M. Sendall, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
-
Trade‐offs in juvenile growth potential vs. Shade Tolerance among subtropical rain forest trees on soils of contrasting fertility
Functional Ecology, 2015Co-Authors: Kerrie M. Sendall, Christopher H. Lusk, Peter B. ReichAbstract:Summary Plant adaptation to gradients of light availability involves a well-studied functional trade-off, as does adaptation to gradients of nutrient availability. However, little is known about how these two major trade-offs interact, and thus, it remains unclear whether and how the nature of the growth–Shade Tolerance trade-off differs on soils of contrasting fertility. We asked whether juvenile growth–Shade Tolerance trade-offs differed in slope and elevation between tree assemblages on nutrient-rich basalt and nutrient-poor rhyolite soils in an Australian subtropical rain forest. We measured the growth of, and the range of light environments occupied by, juveniles (40–120 cm tall) of eight basalt specialists, six rhyolite specialists, and one generalist that was common on both substrates. In situ minimum light requirements were estimated from the 5th percentile of the distribution of naturally regenerated juveniles in relation to daily light transmittance. Stem growth was measured for 12–16 months across a wide range of light environments to estimate the light compensation point of growth of each species. Light compensation points of growth showed nearly a 1 : 1 correspondence with in situ minimum light requirements of species, indicating that whole-plant carbon balance is a key driver of ecological success in low light. Minimum light requirements were negatively correlated with relative growth rate in low light, but correlated positively with growth in high light. Soil type had no effect on either the slope or the elevation of this trade-off, all species aligning around a common growth–Shade Tolerance trade-off, but our results do show a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite. Our results suggest that adaptation to light availability involves fundamentally similar trade-offs on these two substrates of differing fertility. However, a wider range of growth rates and Shade Tolerance on the nutrient-rich basalt soil than on the nutrient-poor rhyolite may help to explain the higher species richness and greater structural complexity of forest stands on the former substrate.
Benoît Courbaud - One of the best experts on this subject based on the ideXlab platform.
-
Covariation between tree size and Shade Tolerance modulates mixed-forest productivity
Annals of Forest Science, 2018Co-Authors: Thomas Cordonnier, Thomas Bourdier, Georges Kunstler, Christian Piedallu, Benoît CourbaudAbstract:AbstractKey messageIn tree communities, tree size inequality reduces productivity and interacts with tree Shade Tolerance to modulate stand productivity, with a higher productivity in stands where Shade-intolerant species dominate Shade-tolerant species in size.ContextPositive diversity–productivity relationships have been reported in different plant communities, including tree communities. These effects may be strongly related to both structural diversity and functional diversity, but also to their interactions if there is a non-random distribution of species functional characteristics among canopy layers.AimsWe explore the relative effects on forest productivity of tree species diversity, tree size inequality, and species Shade Tolerance diversity, as well as the effect of the distribution of tree Shade Tolerance in the canopy.MethodsWe used 11,054 mixed-species forest plots from the French Forest Inventory (IGN) distributed throughout France (2006–2011). We analyzed the effects of species richness, Shade Tolerance diversity, and height inequality on forest plot productivity, represented by basal area annual increment over a period of 5 years, while controlling for first-order structure characteristics (basal area and quadratic mean diameter) and environmental factors (soil water budget and sum of growing degree days). Using the covariance between tree height and Shade Tolerance in mixed species canopies, we also explored the effect of the distribution of species’ Shade Tolerance among canopy layers.ResultsThe results showed a positive effect of species richness (effect size, 0.02) and a negative effect of height inequality (− 0.05) on mixed-forest productivity. We also showed that a negative covariance between Shade Tolerance and height (e.g., higher proportion of Shade-tolerant species in lower height classes) increased productivity (0.01). Shade Tolerance diversity did not affect productivity.ConclusionIn tree communities, as shown previously in monospecific forest stands, tree size inequality reduces productivity. This effect is modulated by the distribution of Shade Tolerance among canopy layers. Previous studies on species diversity effect have generally overlooked the importance of the size structure and the size hierarchy of functional characteristics. These effects are, however, crucial and deserve to be explored in greater detail.
-
Covariation between tree size and Shade Tolerance modulates mixed-forest productivity
Annals of Forest Science, 2018Co-Authors: Thomas Cordonnier, Thomas Bourdier, Georges Kunstler, Christian Piedallu, Benoît CourbaudAbstract:In tree communities, tree size inequality reduces productivity and interacts with tree Shade Tolerance to modulate stand productivity, with a higher productivity in stands where Shade-intolerant species dominate Shade-tolerant species in size. Positive diversity–productivity relationships have been reported in different plant communities, including tree communities. These effects may be strongly related to both structural diversity and functional diversity, but also to their interactions if there is a non-random distribution of species functional characteristics among canopy layers. We explore the relative effects on forest productivity of tree species diversity, tree size inequality, and species Shade Tolerance diversity, as well as the effect of the distribution of tree Shade Tolerance in the canopy. We used 11,054 mixed-species forest plots from the French Forest Inventory (IGN) distributed throughout France (2006–2011). We analyzed the effects of species richness, Shade Tolerance diversity, and height inequality on forest plot productivity, represented by basal area annual increment over a period of 5 years, while controlling for first-order structure characteristics (basal area and quadratic mean diameter) and environmental factors (soil water budget and sum of growing degree days). Using the covariance between tree height and Shade Tolerance in mixed species canopies, we also explored the effect of the distribution of species’ Shade Tolerance among canopy layers. The results showed a positive effect of species richness (effect size, 0.02) and a negative effect of height inequality (− 0.05) on mixed-forest productivity. We also showed that a negative covariance between Shade Tolerance and height (e.g., higher proportion of Shade-tolerant species in lower height classes) increased productivity (0.01). Shade Tolerance diversity did not affect productivity. In tree communities, as shown previously in monospecific forest stands, tree size inequality reduces productivity. This effect is modulated by the distribution of Shade Tolerance among canopy layers. Previous studies on species diversity effect have generally overlooked the importance of the size structure and the size hierarchy of functional characteristics. These effects are, however, crucial and deserve to be explored in greater detail.
-
Difference in Shade Tolerance drives the mixture effect on oak productivity
Journal of Ecology, 2018Co-Authors: Maude Toïgo, Benoît Courbaud, Thomas Perot, Bastien Castagneyrol, Fleur Longuetaud, Hervé Jactel, - Gégout J.c., Patrick ValletAbstract:1. Assessing how species productivity in mixtures is influenced by species Shade Tolerance (ST) and phylogeny would be helpful to improve our general understanding of the relationship between tree species diversity and productivity in forests. 2. We investigated the effects of differences in ST and phylogenetic distances (PDs) between pairs of species on the productivity of Quercus petraea growing in 18 mixtures in lowland temperate forests. We calculated the mixture effect as the difference in productivity of Q. petraea in mixed vs. pure stands. Our analyses were based on data from seven annual campaigns of the French National Forest Inventory covering 1,573 plots. 3. The mixture effect on Q. petraea productivity increased when the ST of the companion species decreased. Compared to its productivity in pure stands, Q. petraea productivity in mixed coniferous stands varied from from
-
Difference in Shade Tolerance drives the mixture effect on oak productivity
Journal of Ecology, 2017Co-Authors: Maude Toïgo, Benoît Courbaud, Thomas Perot, Bastien Castagneyrol, Jean-claude Gégout, Fleur Longuetaud, Hervé Jactel, Patrick ValletAbstract:Assessing how species productivity in mixtures is influenced by species Shade Tolerance and phylogeny would be helpful to improve our general understanding of the relationship between tree species diversity and productivity in forests. We investigated the effects of differences in Shade Tolerance and phylogenetic distances between pairs of species on the productivity of Quercus petraea growing in 18 mixtures in lowland temperate forests. We calculated the mixture effect as the difference in productivity of Q. petraea in mixed vs. pure stands. Our analyses were based on data from seven annual campaigns of the French National Forest Inventory covering 1,573 plots. The mixture effect on Q. petraea productivity increased when the Shade Tolerance of the companion species decreased. Compared to its productivity in pure stands, Q. petraea productivity in mixed coniferous stands varied from -14.6% up to +39.6% as the Shade Tolerance of the companion species inversely varied from highest to lowest. With broadleaved companion species, the mixture effect varied from -10% up to +13.9% with decreasing Shade Tolerance. We found no effect of phylogenetic distance between Q. petraea and the companion species on the mixture effect. Synthesis: Our results confirm that Shade Tolerance is an important driver of the diversity effect on productivity at species level in temperate forests and that phylogenetic distance is not a relevant proxy for species functional dissimilarity. This article is protected by copyright. All rights reserved.
