Limits...
Species identity and neighbor size surpass the impact of tree species diversity on productivity in experimental broad-leaved tree sapling assemblages under dry and moist conditions.

Lübbe T, Schuldt B, Leuschner C - Front Plant Sci (2015)

Bottom Line: Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance.Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis.The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures.

View Article: PubMed Central - PubMed

Affiliation: Plant Ecology and Ecosystems Research, Albrecht von Haller Institute for Plant Sciences, University of Göttingen Göttingen, Germany.

ABSTRACT
Species diversity may increase the productivity of tree communities through complementarity (CE) and/or selection effects (SE), but it is not well known how this relationship changes under water limitation. We tested the stress-gradient hypothesis, which predicts that resource use complementarity and facilitation are more important under water-limited conditions. We conducted a growth experiment with saplings of five temperate broad-leaved tree species that were grown in assemblages of variable diversity (1, 3, or 5 species) and species composition under ample and limited water supply to examine effects of species richness and species identity on stand- and tree-level productivity. Special attention was paid to effects of neighbor identity on the growth of target trees in mixture as compared to growth in monoculture. Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance. The growth performance of some of the species in the mixtures was affected by tree neighborhood characteristics with neighbor size likely being more important than neighbor species identity. Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis. The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures.

No MeSH data available.


Related in: MedlinePlus

Relative growth rate (above- and below-ground) of the five species in the moist (upper panel) and dry treatment (lower panel) in monoculture (second bar of a group), 3-species mixture (3rd bar), 5-species mixture (4th bar), and as average of all constellations (first bar, no hatching) (means ± SE). Different capital letters indicate significantly different species averages (p < 0.05), different small letters significant differences between the three diversity levels within a species. The number of asterisks gives the level of significance for the growth reduction from the moist to the dry treatment of a species (*p < 0.05; ***p < 0.001).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4620412&req=5

Figure 3: Relative growth rate (above- and below-ground) of the five species in the moist (upper panel) and dry treatment (lower panel) in monoculture (second bar of a group), 3-species mixture (3rd bar), 5-species mixture (4th bar), and as average of all constellations (first bar, no hatching) (means ± SE). Different capital letters indicate significantly different species averages (p < 0.05), different small letters significant differences between the three diversity levels within a species. The number of asterisks gives the level of significance for the growth reduction from the moist to the dry treatment of a species (*p < 0.05; ***p < 0.001).

Mentions: When all individuals of a species from all species combinations were pooled in the analysis, productivity (RGRtotal) decreased in the sequence Fraxinus > Tilia > Carpinus > Fagus > Acer in the moist and the dry treatment (Figure 3: first bars of the species blocs). For the other productivity parameters, the species ranking differed in some cases (Table A2).


Species identity and neighbor size surpass the impact of tree species diversity on productivity in experimental broad-leaved tree sapling assemblages under dry and moist conditions.

Lübbe T, Schuldt B, Leuschner C - Front Plant Sci (2015)

Relative growth rate (above- and below-ground) of the five species in the moist (upper panel) and dry treatment (lower panel) in monoculture (second bar of a group), 3-species mixture (3rd bar), 5-species mixture (4th bar), and as average of all constellations (first bar, no hatching) (means ± SE). Different capital letters indicate significantly different species averages (p < 0.05), different small letters significant differences between the three diversity levels within a species. The number of asterisks gives the level of significance for the growth reduction from the moist to the dry treatment of a species (*p < 0.05; ***p < 0.001).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4620412&req=5

Figure 3: Relative growth rate (above- and below-ground) of the five species in the moist (upper panel) and dry treatment (lower panel) in monoculture (second bar of a group), 3-species mixture (3rd bar), 5-species mixture (4th bar), and as average of all constellations (first bar, no hatching) (means ± SE). Different capital letters indicate significantly different species averages (p < 0.05), different small letters significant differences between the three diversity levels within a species. The number of asterisks gives the level of significance for the growth reduction from the moist to the dry treatment of a species (*p < 0.05; ***p < 0.001).
Mentions: When all individuals of a species from all species combinations were pooled in the analysis, productivity (RGRtotal) decreased in the sequence Fraxinus > Tilia > Carpinus > Fagus > Acer in the moist and the dry treatment (Figure 3: first bars of the species blocs). For the other productivity parameters, the species ranking differed in some cases (Table A2).

Bottom Line: Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance.Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis.The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures.

View Article: PubMed Central - PubMed

Affiliation: Plant Ecology and Ecosystems Research, Albrecht von Haller Institute for Plant Sciences, University of Göttingen Göttingen, Germany.

ABSTRACT
Species diversity may increase the productivity of tree communities through complementarity (CE) and/or selection effects (SE), but it is not well known how this relationship changes under water limitation. We tested the stress-gradient hypothesis, which predicts that resource use complementarity and facilitation are more important under water-limited conditions. We conducted a growth experiment with saplings of five temperate broad-leaved tree species that were grown in assemblages of variable diversity (1, 3, or 5 species) and species composition under ample and limited water supply to examine effects of species richness and species identity on stand- and tree-level productivity. Special attention was paid to effects of neighbor identity on the growth of target trees in mixture as compared to growth in monoculture. Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance. The growth performance of some of the species in the mixtures was affected by tree neighborhood characteristics with neighbor size likely being more important than neighbor species identity. Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis. The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures.

No MeSH data available.


Related in: MedlinePlus