Response to nutrient additions by the plant growth forms of sand-plain lowland fynbos, South Africa

Vegetatio ◽  
1988 ◽  
Vol 79 (1-2) ◽  
pp. 89-97 ◽  
Author(s):  
E. T. F. Witkowski

2021 ◽  
Vol 16 (2) ◽  
pp. 155-158
Author(s):  
Ezenwatah Ifeoma Susan ◽  
Ukpaka Chukwujekwu Gratius ◽  
Onyemeka Regland Michael ◽  
Afulukwe Stella Chinyere ◽  
Okoye Elochukwu Chidubem Sunday

The study on the floral diversity of Neni-Nimo watershed in Anaocha L.G.A. of Anambra State was conducted between November 2009 and July 2020. The aim of the study was to find out the species richness and the floral biodiversity of the watershed. In this study, the watershed was divided into three sites, the forested site, the fallow site and the current usage site. The experiment was laid out in a Randomized Complete Block Design. The ecological methods used in this study are the Point Centred Plotless Count sampling technique for areas dominated by trees while the Plot Count technique using quadrats were used for sampling the areas dominated by forbs, shrubs, climbers and grasses. The vegetation data collected was used to estimate the species richness of the different plant growth forms, the diversity and equitability of the various growth forms encountered were calculated using Shanon Weiners diversity index. The Shanno Weiners diversity index shows that the forested areas had the highest floral biodiversity than the fallow and current usage area. Regression analysis shows that a significant relationship exists between species abundance and floral biodiversity at a p-value of <0.05 for all plant growth forms in the watershed except for grasses and as abundance increases, diversity also increases.



1991 ◽  
Vol 48 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Michele Dionne ◽  
Carol L. Folt

In this laboratory study we measured the independent effects of macrophyte growth form, plant density, and prey abundance on the foraging rate of the pumpkinseed sunfish (Lepomis gibbosus). We demonstrate that macrophyte growth forms are not all similar in their effects on fish foraging. Prey capture rates of pumpkinseeds foraging among Scirpus validus (cylindrical stems) were 53 and 365% times greater than for Potamogeton amplifolius (leafy stems) for cladoceran (Sida crystallina) and larval damselfly (Coenagrionidae) prey, respectively. Plant growth form influenced prey capture rates more than charges in natural plant density. Plant density effects ranged from none on damselfly capture rates to a 29% decline in cladoceran capture rate over a twofold increase in plant density. Our results indicate that in plant-structured habitats, variation in plant growth form can be an important determinant of fish foraging and habitat associations.



2007 ◽  
pp. 379-384 ◽  
Author(s):  
T. Speck ◽  
N.P. Rowe
Keyword(s):  


2018 ◽  
Vol 427 (1-2) ◽  
pp. 305-319 ◽  
Author(s):  
Qiang Zhang ◽  
Gaoming Xiong ◽  
Jiaxiang Li ◽  
Zhijun Lu ◽  
Yuelin Li ◽  
...  




2018 ◽  
Vol 187 (1) ◽  
pp. 118-136 ◽  
Author(s):  
Natalia Contreras-Ortiz ◽  
Guy W Atchison ◽  
Colin E Hughes ◽  
Santiago Madriňán


2016 ◽  
Author(s):  
Di Tian ◽  
Peng Li ◽  
Wenjing Fang ◽  
Jun Xu ◽  
Yongkai Luo ◽  
...  

Abstract. Atmospheric nitrogen (N) deposition has been a noteworthy aspect of global change. Previous observational studies in temperate and tropical forests have focused on the effects of N deposition on tree growth. Here we asked how trees and other plant growth forms respond to experimental N deposition in a subtropical forest in China. We conducted a four-year N fertilization experiment in a subtropical evergreen forest in southeastern China with three treatment levels applied to 9 20 × 20 m plots and replicated in three blocks. We classified the plants to trees, saplings, shrubs(including tree seedlings) and ground-cover plants (ferns) according to the growth forms, then we measured the absolute and relative basal area increments of trees and saplings, and the aboveground biomass of understory shrubs and ferns. In addition, we grouped individuals of the dominant tree species Castanopsis eyrei into three size classes and analyzed their growth responses to N fertilization separately. Although the total tree growth on plot level did not show a significant response to the N fertilization, the small trees with DBH (diameter at breast height) values of 5–10 cm were hindered by N fertilization, while the growth of large trees with DBH > 10 cm showed neutral or weakly positive responses to N fertilization. Small trees, saplings and particularly understory shrubs and ground-cover ferns suppressed seriously by increasing N fertilization. The proportions of plant mortality in N-fertilized plots were higher than in unfertilized plots and most of the dead individuals were small trees, saplings, shrubs and ferns. N deposition potentially leads to increased growth of larger plant individuals at tree layer in the forest community and suppresses the growth and survival of other individuals at understory and ground-cover layers. Therefore, differences in the growth responses of different plant growth forms and individual sizes should be taken into account when evaluating the effects of N deposition on the functioning of these forest ecosystems, including their potential for carbon storage.



Author(s):  
Maya A. Zomer ◽  
Paul M. Ramsay

AbstractQuestionsFire suppression policies have been widely adopted in the páramo grasslands of the northern Andes to protect their biodiversity and ecosystem services. Páramos have been regularly burned for many years, and it is not clear how páramo vegetation will respond to significant changes in their fire regimes. This study investigates differences in plant growth form composition, light levels and soil temperatures in páramo plots representing a range of recovery times since the last fire.LocationReserva Ecológica El Ángel and La Bretaña Nature Reserve, Carchi, Northern Ecuador.MethodsWe assessed the frequency of ten páramo growth forms, vegetation height, soil temperature, and light intensity in fifteen fire sites with historical records of fire (<1 – 15 years since fire), and one recently unburned site (at least 40 years since fire). A chronosquence of sites was used to assess potential changes in plant community composition in post-fire succession of páramo.ResultsThe recovery of páramo vegetation after fire comprised three phases: initial recruitment with high growth form diversity, followed by reduced diversity, light and soil temperatures in dense tussock vegetation, and ultimately canopy height stratification with a return of diversity. All but one plant growth forms were represented in each of the three phases, and the changes reflected differences in relative abundance.ConclusionsPost-fire páramo succession is characterized by clear shifts in the relative abundance of plant growth forms, ending with (co-)dominance of upright shrubs. The long-term consequences of such shifts for biodiversity and ecosystem function, given the widespread adoption of fire suppression policies in the páramo need careful, evidence-based consideration.





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