Week four: Rainforest and Aquatic plants, A brief discription of adaptations

Simple Rainforest Adaptations

Viewed:30/03/17

https://www.youtube.com/watch?v=zu6p3kdfqwg

This week’s blog is about the specialisation of plants from rainforests and aquatic environments.

There is a long tradition of research behind the notion that plants respond morphologically to changes in their environment (Schlichting, 1986). Rainforest plants have adapted to a better richness of resources in their immediate environment, with typically much higher humidity and rainfall, and are often situated in high sun locations. In addition, many rainforest plants have developed a method of seed dispersal where they use the aid of terrestrial creatures to disperse their seeds for the better success of the seedlings into the next generation. Because of the high resource availability of these plants, some grow to be massive in size. Some rainforest trees have grown pronounced trunks and have quite heavy and dense leaves and foliage, taking full advantage of the abundance of resources available (figure 1).

Figure 1. Ecuadorian Rainforest 

Viewed 30/03/17: http://bit.ly/2mQVubo

The evolutionary theory behind the diversity of many species in rainforest environments has been narrowed to the three most likely explanations: Genetic drift, specialisation to environment, and repeated geographic isolation followed by remixing of species during Pleistocene climatic fluctuations (Denslow, 1987). Phenotypic plasticity can also be a contributing factor. The evolution of rainforests has potentially resulted from the exploitation of resources available, and as such the plants have become successful and competitive to fill new niches(Brokaw & Busing, 2000).

Aquatic plants have alternatively had to learn to grow under the constraints of water density and the hurdles involved with living in high saline environments. One of the main problems of submergence is the shortage of oxygen to submerged tissue due to the slow diffusion of gases in water (Mommer & Visser, 2005), this involves a change of strategy for the plants, for whichever way this change came about, the plants have actively evolved by undertaking a change in the leaf structure (figure 2), their photosynthetic process and reproductive strategies, as the avenues previously used was most likely no longer available. In particular for plants that undergo flood stressors, it is less a morphological change and more a physiological change, put simply, an important part of survival for these plants was learning how to get oxygen and sunlight whilst in these environments.

Figure 2. Aquatic pond plants

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References:

Brokaw, N. Busing, R. 2000, Niche versus chance and tree diversity in forest gaps, Trends in Ecology & Evolution, Vol 15,Issue 5, pp 183-188


Denslow, J. 1987, Tropical Rainforest Gaps and Tree Species Diversity, Annual review of ecology and systematics, pp 431-451

Mommer, L. Visser, E. 2005, Underwater Photosynthesis in Flooded Terrestrial Plants: A matter of leaf plasticity, Annals of Botany, Vol 96, Issue 4, pp 581-589

Schlichting, C. 1986 The Evolution of Phenotypic Plasticity in Plants, Annual review of ecology and systematics,pp 667-673