The effects of size of opening in vegetation and litter cover on seedling establishment of goldenrods ( Solidago spp.)

We investigated the effects of size of opening in the vegetation and litter cover on seedling establishment of two species of goldenrods ( Solidago spp.) in an abandoned field in southwestern Michigan, U.S.A. Seeds of S. canadensis and S. juncea were sown into clipped plots, ranging from 0 cm (control, unclipped) to 100 cm in diameter, with and without litter. Seedling emergence, survival and growth were followed for one year. Soil moisture was not significantly different among the opening sizes, but, within a size, tended to be lower when litter was removed. Light intensity at the soil surface was positively related to opening size early in the growing season, but later in the growing season reached a maximum in intermediate-sized openings and then leveled off.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47747/1/442_2004_Article_BF00379516.pd

Kerangas Forest Plots Data

Text to files on Bruenig’s KF plot data Of the 57 small plots in Bornean Kerangas (Heath) Forest recorded by E. F. Bruenig between 1959 and 1963, in Sarawak (Malaysia) and Brunei (Bruenig 1974), 38 (numbered 20-57) were re-analyzed by Newbery (1991). Six plots [29,31,32,42,54,55] were 1, two 2 [45,49], five 3 [34,35,46,56,57], and twenty-five 5 [the remainder], square chains in area (1 ch2 = 405 m2). The common minimum tree girth (gbh) was 3” (7.62 cm): all trees were measured for gbh and identified. Tree counts were divided into three size (gbh) classes: I, 3.0 – 11.9” (7.6 – 30.2 cm); II, 12.0 – 23.9” (30.5 – 60.7 cm); and III, ≥ 24.0” (≥ 61.0 cm). The two main data files are: ‘kerplot_dat.txt’ and ‘kerdict_dat.txt’. The first file lists all trees per plot, as columns (1) plot – plot number, (2) gen – genus code, (3) spec – species code, (4 – 6) numbers of trees in size classes I – III; (7) total number of trees, (8) BA, basal area, in cm2. This a space-delimited ASCII file, values left-justified, readable by most statistical programs and as input to R. The second file lists all the codes with their full Latin names, grouped by family (637 taxa). The names were those given as of 1974: the modern user may want to revise them using an international plant names’ index. Full background details to the study are found in Bruenig (1974). Plot locations and environmental variables are also given in Fig. 1 and Table 3 of Newbery (1991). For the purposes of numerical analysis, basal area and density of each species per plot were calculated per 5-ch2 (cm2 and N resp.). The data set was reduced to 381 common taxa: procedures and criteria are given in Newbery (1991). Three further files given here are: basal area and density abundances in the 38 plots as ‘kerbar38_dat.txt’ and ‘kerden38_dat.txt’, with a list of the corresponding common-taxon codes in ‘ker38_codes.txt’. The two abundance files are written in the Cornell Condensed Format of programs DECORANA and CANOCO. With the transformations and options described normalized PCA ordinations of the plots in Newbery (1991) can be reproduced. Reference: Brunig, E. F. 1974. Ecological Studies in the Kerangas Forests of Sarawak and Brunei. Borneo Literature Bureau, Kuching, for the Sarawak Forest Department

Data from: Floristic variation within kerangas (heath) forest: re-evaluation of data from Sarawak and Brunei

The variation in species composition of trees greater-than-or-equal-to 7.6 cm gbh in thirty-eight plots (mostly c. 0.2 ha in extent) from physiognomically-defined kerangas forest were re-analyzed by principal components analysis ordination (species centering and standardization by sample norm). Analyses were performed separately on basal area abundances, on the densities of trees in three size classes (greater-than-or-equal-to 7.6, greater-than-or-equal-to 30.5 and greater-than-or-equal-to 61.0 cm gbh) and on the density of small and large trees (7.6- < 30.5 and 30.5- < 61.0 cm gbh). A total of 636 taxa were reduced to 381 for analysis, removing those of very low density and plot frequency. Three groups of plots were identified: forest at low elevation, and generally coastal, on deep humus podzols; forest at intermediate elevation on mostly red-yellow podzols with affinities to dipterocarp forest; and forest at high elevation on mostly peaty podzols. The first group was divisible into five subgroups along a drainage gradient, while the more poorly drained plots showing affinities to peat-swamp forest. Forty to eighty of the taxa, depending on the criteria for selection, were sufficient to define a stable, reduced spatial structure of the data matrix. Two subgroups, both coastal on deep podzols, represent the extreme form of kerangas forest per se. A comparison of Agathis borneensis- and Shorea albida-dominated plots revealed few other associated and differentiating taxa. Patterns were clearest from analyses of basal area data and of densities of all and small trees. Ordinations and grouping of plots for small, but not large, tree densities were similar to those for basal area. Different species were differentiated on the basis of the abundance measure, leading to group (tabular) definition of associations in a dual manner. A new system of summarization is presented which combines basal area, density and frequency in a graded hierarchical approach. The association between vegetation and soil type was difficult to unravel because of the limited environmental space sampled. Soil type was confounded with elevation, rainfall and geographical location. A major factor is clay content probably affecting nutrient status and water holding properties. 'Modal analysis' of small tree densities showed clearest patterns in this respect. There were no patterns at the family or genus level, nor in leaf size spectra within kerangas. Problems in the treatment, analysis and summarization of tropical forest data sets are discussed. These problems centre on the scale and intensity of field sampling and the advantages of measuring small trees leading to a dual basal area and density approach. All published studies, including this one, within kerangas forest have used inadequate sampling for the purposes of revealing species changes with respect to soil type and composition

Data from: Floristic variation within kerangas (heath) forest: re-evaluation of data from Sarawak and Brunei

The variation in species composition of trees greater-than-or-equal-to 7.6 cm gbh in thirty-eight plots (mostly c. 0.2 ha in extent) from physiognomically-defined kerangas forest were re-analyzed by principal components analysis ordination (species centering and standardization by sample norm). Analyses were performed separately on basal area abundances, on the densities of trees in three size classes (greater-than-or-equal-to 7.6, greater-than-or-equal-to 30.5 and greater-than-or-equal-to 61.0 cm gbh) and on the density of small and large trees (7.6- < 30.5 and 30.5- < 61.0 cm gbh). A total of 636 taxa were reduced to 381 for analysis, removing those of very low density and plot frequency. Three groups of plots were identified: forest at low elevation, and generally coastal, on deep humus podzols; forest at intermediate elevation on mostly red-yellow podzols with affinities to dipterocarp forest; and forest at high elevation on mostly peaty podzols. The first group was divisible into five subgroups along a drainage gradient, while the more poorly drained plots showing affinities to peat-swamp forest. Forty to eighty of the taxa, depending on the criteria for selection, were sufficient to define a stable, reduced spatial structure of the data matrix. Two subgroups, both coastal on deep podzols, represent the extreme form of kerangas forest per se. A comparison of Agathis borneensis- and Shorea albida-dominated plots revealed few other associated and differentiating taxa. Patterns were clearest from analyses of basal area data and of densities of all and small trees. Ordinations and grouping of plots for small, but not large, tree densities were similar to those for basal area. Different species were differentiated on the basis of the abundance measure, leading to group (tabular) definition of associations in a dual manner. A new system of summarization is presented which combines basal area, density and frequency in a graded hierarchical approach. The association between vegetation and soil type was difficult to unravel because of the limited environmental space sampled. Soil type was confounded with elevation, rainfall and geographical location. A major factor is clay content probably affecting nutrient status and water holding properties. 'Modal analysis' of small tree densities showed clearest patterns in this respect. There were no patterns at the family or genus level, nor in leaf size spectra within kerangas. Problems in the treatment, analysis and summarization of tropical forest data sets are discussed. These problems centre on the scale and intensity of field sampling and the advantages of measuring small trees leading to a dual basal area and density approach. All published studies, including this one, within kerangas forest have used inadequate sampling for the purposes of revealing species changes with respect to soil type and composition