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Ecophysiological responses to different forest patch type of two codominant tree seedlings.

Duan R, Huang M, Kong X, Wang Z, Fan W - Ecol Evol (2014)

Bottom Line: Dry leaf mass per area (LMA), Chlorophyll a + b concentration (Chl), carotenoids (Car), and nitrogen content per area (N a ) all responded to changes in light across patch type, but B. controversum showed greater sensitivity and changes than C. glauca.From G to M patch, B. controversum showed significant changes in gas exchange, while C. glauca showed only small changes.Ecophysiological trait partitioning of response to light in different patches provides a possible explanation of a coexistence mechanism.

View Article: PubMed Central - PubMed

Affiliation: College of Life Science, Anqing Normal University Anqing, 246011, China.

ABSTRACT
According to gap-phase dynamics theory, forests can be divided into four distinct patch types: gap patch (G), building patch (B), mature patch (M), and degeneration patch (D). Varying light conditions across patch types are one of the most important factors affecting the coexistence of vegetation. Mechanisms of coexistence can be understood through detailed knowledge of ecophysiological responses of codominant tree seedlings to patch types. The following study was conducted to determine ecophysiological responses of Cyclobalanopsis glauca (an evergreen broad-leaved species) and Bothrocaryum controversum (a deciduous broad-leaved species) to four different patch types. During the gap-phase dynamics, light intensity and the magnitude of change in the four different patches followed the order of: G > B > D > M. Both species had the greatest photosynthetic capacity in the G patch. Dry leaf mass per area (LMA), Chlorophyll a + b concentration (Chl), carotenoids (Car), and nitrogen content per area (N a ) all responded to changes in light across patch type, but B. controversum showed greater sensitivity and changes than C. glauca. From G to M patch, the maximal quantum efficiency of PSII (F v /F m ) had a larger variation magnitude for B. controversum than for C. glauca. From G to M patch, B. controversum showed significant changes in gas exchange, while C. glauca showed only small changes. Ecophysiological trait partitioning of response to light in different patches provides a possible explanation of a coexistence mechanism.

No MeSH data available.


Related in: MedlinePlus

The diurnal variation of chlorophyll fluorescence parameters (qP, qN, ΦPSII, and ETR) in Bothrocaryum controversum and Cyclobalanopsis glauca seedlings in the gap-phase dynamics (G, B, M, and D) on 23–29 July 2012. One B. controversum seedling and one C. glauca seedling were randomly selected in each patch. Total eight seedlings (four B. controversum seedlings and four C. glauca seedlings) were measured in four selected patches (the same four patches as those in Fig.2).
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fig04: The diurnal variation of chlorophyll fluorescence parameters (qP, qN, ΦPSII, and ETR) in Bothrocaryum controversum and Cyclobalanopsis glauca seedlings in the gap-phase dynamics (G, B, M, and D) on 23–29 July 2012. One B. controversum seedling and one C. glauca seedling were randomly selected in each patch. Total eight seedlings (four B. controversum seedlings and four C. glauca seedlings) were measured in four selected patches (the same four patches as those in Fig.2).

Mentions: In the G patch, the maximal quantum efficiency of PSII (Fv/Fm) values of B. controversum and C. glauca was the highest (around 0.8). The two species both had significant differences among the four different patches in the PSII (Fv/Fm) (Fig.3). From G to M patch, the Fv/Fm values of B. controversum and C. glauca decreased by approximately 44.4% and 22.8%, respectively (Fig.3). At G patch, the values of the photochemical quenching (qP), the actual photochemical efficiency of PSII (ΦPSII), and electron transport rate (ETR) measured late morning/early afternoon were higher for B controversum than for C. glauca (Fig.4). At 14:00 h in the G patch, there was some photoinhibition (a decreasing photosynthetic efficiency with high light at noon) for the two species, as nonphotochemical quenching (qN) was more than 0.6, and qP, ΦPSII, and ETR were less than 0.5, 0.4, and 60 μmol electrons m−2·sec−1, respectively (Fig.4). In the G patch, qN, ΦPSII, and ETR have a greater diurnal variation (the difference of the max value and the min value from 6:00 to 18:00) for B. controversum than for C. glauca (0.44 vs. 0.39 of qN, 0.539 vs. 0.301 of ΦPSII, 92 vs. 41 of ETR), while qP has no significant difference (Fig.4). In the M patch, qP and ΦPSII have a greater diurnal variation for B. controversum than for C. glauca (0.47 vs. 0.37 of qP, 0.105 vs. 0.037 of ΦPSII), while qN and ETR have no significant difference (Fig.4).


Ecophysiological responses to different forest patch type of two codominant tree seedlings.

Duan R, Huang M, Kong X, Wang Z, Fan W - Ecol Evol (2014)

The diurnal variation of chlorophyll fluorescence parameters (qP, qN, ΦPSII, and ETR) in Bothrocaryum controversum and Cyclobalanopsis glauca seedlings in the gap-phase dynamics (G, B, M, and D) on 23–29 July 2012. One B. controversum seedling and one C. glauca seedling were randomly selected in each patch. Total eight seedlings (four B. controversum seedlings and four C. glauca seedlings) were measured in four selected patches (the same four patches as those in Fig.2).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4314260&req=5

fig04: The diurnal variation of chlorophyll fluorescence parameters (qP, qN, ΦPSII, and ETR) in Bothrocaryum controversum and Cyclobalanopsis glauca seedlings in the gap-phase dynamics (G, B, M, and D) on 23–29 July 2012. One B. controversum seedling and one C. glauca seedling were randomly selected in each patch. Total eight seedlings (four B. controversum seedlings and four C. glauca seedlings) were measured in four selected patches (the same four patches as those in Fig.2).
Mentions: In the G patch, the maximal quantum efficiency of PSII (Fv/Fm) values of B. controversum and C. glauca was the highest (around 0.8). The two species both had significant differences among the four different patches in the PSII (Fv/Fm) (Fig.3). From G to M patch, the Fv/Fm values of B. controversum and C. glauca decreased by approximately 44.4% and 22.8%, respectively (Fig.3). At G patch, the values of the photochemical quenching (qP), the actual photochemical efficiency of PSII (ΦPSII), and electron transport rate (ETR) measured late morning/early afternoon were higher for B controversum than for C. glauca (Fig.4). At 14:00 h in the G patch, there was some photoinhibition (a decreasing photosynthetic efficiency with high light at noon) for the two species, as nonphotochemical quenching (qN) was more than 0.6, and qP, ΦPSII, and ETR were less than 0.5, 0.4, and 60 μmol electrons m−2·sec−1, respectively (Fig.4). In the G patch, qN, ΦPSII, and ETR have a greater diurnal variation (the difference of the max value and the min value from 6:00 to 18:00) for B. controversum than for C. glauca (0.44 vs. 0.39 of qN, 0.539 vs. 0.301 of ΦPSII, 92 vs. 41 of ETR), while qP has no significant difference (Fig.4). In the M patch, qP and ΦPSII have a greater diurnal variation for B. controversum than for C. glauca (0.47 vs. 0.37 of qP, 0.105 vs. 0.037 of ΦPSII), while qN and ETR have no significant difference (Fig.4).

Bottom Line: Dry leaf mass per area (LMA), Chlorophyll a + b concentration (Chl), carotenoids (Car), and nitrogen content per area (N a ) all responded to changes in light across patch type, but B. controversum showed greater sensitivity and changes than C. glauca.From G to M patch, B. controversum showed significant changes in gas exchange, while C. glauca showed only small changes.Ecophysiological trait partitioning of response to light in different patches provides a possible explanation of a coexistence mechanism.

View Article: PubMed Central - PubMed

Affiliation: College of Life Science, Anqing Normal University Anqing, 246011, China.

ABSTRACT
According to gap-phase dynamics theory, forests can be divided into four distinct patch types: gap patch (G), building patch (B), mature patch (M), and degeneration patch (D). Varying light conditions across patch types are one of the most important factors affecting the coexistence of vegetation. Mechanisms of coexistence can be understood through detailed knowledge of ecophysiological responses of codominant tree seedlings to patch types. The following study was conducted to determine ecophysiological responses of Cyclobalanopsis glauca (an evergreen broad-leaved species) and Bothrocaryum controversum (a deciduous broad-leaved species) to four different patch types. During the gap-phase dynamics, light intensity and the magnitude of change in the four different patches followed the order of: G > B > D > M. Both species had the greatest photosynthetic capacity in the G patch. Dry leaf mass per area (LMA), Chlorophyll a + b concentration (Chl), carotenoids (Car), and nitrogen content per area (N a ) all responded to changes in light across patch type, but B. controversum showed greater sensitivity and changes than C. glauca. From G to M patch, the maximal quantum efficiency of PSII (F v /F m ) had a larger variation magnitude for B. controversum than for C. glauca. From G to M patch, B. controversum showed significant changes in gas exchange, while C. glauca showed only small changes. Ecophysiological trait partitioning of response to light in different patches provides a possible explanation of a coexistence mechanism.

No MeSH data available.


Related in: MedlinePlus