Credit
We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
Purpose
Context: Mansonia altissima A. Chev. is a species with economic value found in moist semi-deciduous forests of tropical Africa. The analysis of spatial distribution patterns can help understand the ecology of this species in forest stands dominated by emergent pioneer tree species like Ceiba pentandra (L.) Gaertn and Triplochiton scleroxylon K. Schum.
Aims: The main objective was to assess the spatial distribution patterns of M. altissima and spatial relationships with C. pentandra and T. scleroxylon in their natural habitat.
Results: Aggregations were detected in juvenile and premature M. altissima. Size and scales of spatial aggregation were inversely proportional to the DBH size. Inters-pecific associations were only significant at the similar life stages for M. altissima and C. pentandra. Both species were positively associated within radius ≥ 3 m. At non-similar life stages they displayed a repulsion or random pattern. M. altissima and T. scleroxylon generally displayed the independent distribution patterns at all life stages.
Conclusion: C. pentandra like pioneer could play the role of nurse plants in management of M. altissima populations providing them a moderate forest shade in large gaps for first years.
Lineage
Spatial Point Pattern Analysis: The sampling design was constituted by ten (10) forest dynamics plots, one-ha each. A plot was divided into sixteen (16) consecutive subplots, 625 m² (25 m x 25 m), constituting the unities of data collection. All individual trees of M. altissima, C. pentandra and T. scleroxylon with a diametergreater than or equal to 1 cm were measured. The position of each tree was determined in two orthonormal vectors whose origin was fixed to upper left corner of each subplot. Geographical coordinates (x ; y) of a tree A within one-ha plot were determined as follow: A(x ; y) = (x_1 + x_0 ; y_1 + y_0). For trees belonging to the same subplot, distances x_0 and y_0 take the values 0 m, 25 m, 50 m or 75 m according to the position of the subplot (25 m x 25 m) within the one-ha plot. In each subplot, distances x_1 and y_1 define the position of a tree A in orthonormal vectors.
The attached metadata has is made from a CSV file named "dataset_full" containing a spreadsheet named "full" for full data of the three species.This dataset file contains five columns. The first "Species_names" contains the scientific name of species. The second column named "Life_stages" contains the three life stages of species. The third column named "DBH(cm)" contains the diameter at breast height, measured at 1.3 m above ground. The fourth and fifth column named "X(m), Y(m)" contain the geographical coordinates of trees. Note that another file named "figures" contains the summary statistics from analyses performed with file "dataset_full".
The file named "figures" contains four spreadsheets. The spreadsheet named "Mansonia_LifeStages" contains the summary statistics and spatial distribution patterns of Mansonia altissima var. altissima in each life stage. The spreadsheet named "associations_Masonia" contains the summary statistics and intraspecific association patterns of Mansonia altissima trees. The spreadsheet named "Masonia&Ceiba" contains the summary statistics and interspecific association patterns between Mansonia altissima and Ceiba pentandra. The spreadsheet named "Masonia&Triplochiton" contains the summary statistics and inter-specific association patterns between Mansonia altissima and Triplochiton scleroxylon.
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