Tolerance and self-tolerance of trees

Zeide, Boris

doi:10.1016/0378-1127(85)90031-3

Cited by 133 publications

(94 citation statements)

References 11 publications

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“…The observed significant relationships between thinning slope and each of two biological variables-plant group and shade tolerance-indicate that differences in thinning slopes are at least partly due to systematic biological differences and are not simply random measurement errors about a value described by a "law." Zeide (1985) also concluded that the thinning slope is not a constant, but rather changes systematically with species and site. As suggested by Sprugel (1 984), the thinning slope of y = -% (p = -1/2) is the exception rather than the rule.…”

Section: Resultsmentioning

confidence: 98%

“…Deviations of the thinning slope from the predicted value are particularly important because P is the exponent of a power relationship, B = KNo, so small differences in /3 represent large differences in the predictions of the equation (Weller 1985, Zeide 1985. A total of 62% of the data sets are either useless for testing the rule or in quantitative disagreement with it, and only 38% potentially support the rule.…”

Section: Resultsmentioning

confidence: 99%

“…Most of the evidence for the self-thinning rule has been analyzed in log %log Nform, since only Westoby and his colleagues, Mook and van der Toorn (1982), and Zeide (1985) have used the log B-log N formulation. Most studies may, then, suffer from one or more of the problems illustrated in the preceding examples: the points selected for analysis may not be the best Fagopyrum esculentum where population o received five times as much fertilizer as population (Furnas 1981).…”

Section: Choosing the Best Mathematical Representationmentioning

confidence: 99%

“…(3) The thinning slopes of plant groups were compared to determine if thinning line parameters vary among groups or if a single thinning rule applies to all plants. (4) The constancy of thinning line parameters with respect to a functional measure of plant performance was evaluated by testing for significant correlations of thinning slope and intercept with shade tolerance, a common forestry measure summarizing the ability of a species to regenerate in the presence of competition (Baker 1949, Harlow et al 1978, Zeide 1985. Previous work suggests that shade-tolerant trees may have higher thinning intercepts (Westoby andHowell 198 1, Lonsdale andWatkinson 1983, Dean andLong 1985) or steeper thinning slopes ) than intolerant trees.…”

Section: New Tests Of the Self-thinning Rulementioning

confidence: 99%

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A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning

Weller¹

1987

Ecological Monographs

423

369

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Abstract. The self-thinning rule predicts that for a crowded even-aged plant population a log-log plot of average plant mass vs. plant density will reveal a straight "self-thinning" line of slope -%. The rule is supported by examples from many individual populations, and by the existence of an interspecific relationship that yields a line of slope -% in a loglog plot displaying average mass and density data from many populations of different species. I examined and reanalyzed the evidence to evaluate the strength of support for this widely accepted rule.Some problems in fitting thinning lines and testing agreement with the rule have no truly satisfactory solution, but three improvements on commonly used methods were made: the analysis related stand biomass density to plant density because the alternative of relating average plant mass to plant density is statistically invalid; principal components analysis was used rather than regression, because regression relies on unrealistic assumptions about errors in the data; and statistical tests of hypotheses were used to interpret the results.The results of this reanalysis were that 19 of 63 individual-population data sets previously cited in support of the thinning rule actually showed no significant correlation between stand biomass density and plant density, and 20 gave thinning slopes significantly different ( P < .05) from the thinning rule prediction. Four other analyses provided additional evidence against a single quantitative thinning rule for all plants: slopes of the thinning lines were more variable than currently accepted, differed significantly among plant groups, were significantly correlated with shade tolerance in forest trees, and differed among stands of the same species. The same results held for the intercepts of self-thinning lines.Despite the failure of the thinning rule for individual populations, the combined data for all populations are still consistent with an interspecific relationship of slope -3/,; therefore, the existence of the interspecific relationship does not necessarily support the withinpopulation thinning rule. The within-population and interspecific relationships are apparently different phenomena that may arise from different constraints, so the two relationships should be tested and explained separately. power law.The self-thinning rule (also called the -% power rule or Yoda's law) describes a relationship between size and density in even-aged plant populations that are crowded but actively growing. If competition from other populations and crowding-independent stresses (drought, fire, disease, etc.) are absent, mortality or "thinning" is caused by competition within the population, hence the term "self-thinning." Yoda et al. Two lines of evidence support this relationship as an ecological "rule" or "law" governing even-aged plant populations. First, the slopes of many reported thinning lines are near y = -%, including data from monospecific populations ranging in size from small herbs to large trees , White and Harper 1970, Wh...

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Choosing the Best Mathematical Representationmentioning

confidence: 99%

Section: New Tests Of the Self-thinning Rulementioning

confidence: 99%

See 2 more Smart Citations

A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning

Weller¹

1987

Ecological Monographs

423

369

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“…Yoda et al (1963) Apesar da lei ter se tornado amplamente aceita (White & Harper, 1970;Harper, 1977;White, 1980White, , 1981White, , 1985Westoby, 1984), sua justificativa matemática original foi reconhecida como uma aproximação grosseira (Yoda et al, 1963) e muito simplificada (White, 1981). Alguns autores questionaram a validade da lei (Weller, 1985(Weller, , 1987(Weller, , 1989(Weller, , 1990(Weller, , 1991Zeide, 1985Zeide, , 1987, alegando que nem todas observações acompanhariam a dinâmica de auto-desbaste definida pela inclinação de -3/2. Lonsdale (1990), após uma análise cuidadosa das descobertas de Weller (1985) e Zeide (1987), concluiu que até então não havia evidências para a existência de uma lei de autodesbaste (-1/2 ou -3/2).…”

Section: Conceituação Da Lei Do Auto-desbaste (Self Thinning Rule)unclassified

Compensação tamanho/densidade populacional de perfilhos em pastagens de Cynodon spp.

Sbrissia¹

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Estimating the self‐thinning boundary line for oak mixed forests in central China by using stochastic frontier analysis and a proposed variable density model

Long

Si-qi

Shi

et al. 2022

Ecology and Evolution

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A suitable self‐thinning model is fundamental to effective density control and management. Using data from 265 plot measurements in oak mixed forests in central China, we demonstrated how to estimate a suitable self‐thinning line for oak mixed forests from three aspects, i.e., self‐thinning models (Reineke's model and the variable density model), statistical methods (quantile regression and stochastic frontier analysis), and the variables affecting stands (topography and stand structure factors). The proposed variable density model, which is based on the quadratic mean diameter and dominant height, exhibited a better goodness of fit and biological relevance than Reineke's model for modeling the self‐thinning line for mixed oak forests. In addition, the normal‐truncated normal stochastic frontier model was superior to quantile regression for modeling the self‐thinning line. The altitude, Simpson index, and dominant height–diameter ratio (Hd$$ {H}_{\mathrm{d}} $$/D) also had significant effects on the density of mixed forests. Overall, a variable density self‐thinning model may be constructed using stochastic frontier analysis for oak mixed forests while considering the effects of site quality and stand structure on density. The findings may contribute to a more accurate density management map for mixed forests.

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Tolerance and self-tolerance of trees

Cited by 133 publications

References 11 publications

A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning

A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning

Compensação tamanho/densidade populacional de perfilhos em pastagens de Cynodon spp.

Estimating the self‐thinning boundary line for oak mixed forests in central China by using stochastic frontier analysis and a proposed variable density model

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