Can I pretend the paper doesn't exist?

Well, I’ve done it.  I developed my proposal for my Master’s thesis project.  I came up with some questions, associated hypotheses, potential field methods and study organisms.  So I’m done working on my project until the May field season starts, right?

Wrong.  I’ve been keeping busy by reading any paper that might have something to do with my project.  Unfortunately, this is making me feel less and less prepared all the time.  Each paper brings up new facts, hypothesis, or field methods I hadn’t even thought about; putting the validity of my project to question. 

An old paper by Elizabeth Newell is one of those papers.  It has definitely caused some stress and worry, and has put a kink in my proposed sampling methods.  Let me summarize this paper for you, so you can have a little taste of my study without giving the details away.



California buckeye, image from:

http://www.msnucleus.org/

Reproduction in plants is linked to vegetative growth.  Thus, it has been suggested that resource allocation to reproduction can reduce likelihood of survival; reduced resources are then available for other necessary functions, such as leaf growth for light capture and photosynthesis.

Newell tested this claim; specifically, whether or not reproduction in one year incurs costs of vegetative growth in the following year.  She used a shoot-level approach in California buckeye (Aesculus californica) – a drought deciduous species.

 

California buckeye flowers, image from:

http://www.calfloranursery.com/

In March 1986, Newell harvested fifteen random terminal shoots from a single buckeye tree in Washington; five flowered and produced fruit in 1985, five flowered but did not produce fruit, and five didn’t flower at all. 

For each shoot, leaf area, leaf number, stem length, and flowering presence were recorded.  As well, the collected leaves and stems from each shoot were dried, weighed, and analysed for nitrogen concentration.

California buckeye fruits, image from:

http://www.primitiveways.com/

Newell found that fruit production in 1985 had dramatic detrimental effects on vegetative growth the following year.  Shoots that produced fruit in 1985 had shoots with yellow, unexpanded leaves in 1986, whereas shoots that didn’t produce fruit in 1986 had fully expanded and dark green leaves.  As well, shoots that produced fruit in 1985 had significantly reduced shoot dry weight, leaf area, and leaf N concentration in 1986 compared to shoots didn’t flower or only flowered in 1985.

Interestingly, shoots that only flowered and shoots that didn’t flower at all in 1985 did not differ significantly in any of the above traits.  This suggests that flowering has relatively few resource costs compared to fruit production.



Table 3 from Newell (1991) demonstrating the detrimental effects fruit production
in 1985 had on vegetative growth in 1986.

It’s clear that fruit production in one year greatly affects vegetative growth – among other unmentioned functions and properties – the following year.  As a result, my supervisor and I are currently redesigning my field methods to account for these findings. 

Even though finding and reading this paper has been discouraging, it will ensure that my project is valid and unique; I don’t want is to replicate someone else’s project or conduct my field work without considering all the past research and findings.  Plus, all the background reading has boosted my critical thinking and problem-solving skills, helping me rework my ideas to make them fabulous!

Sources:

Newell, EA (1991) Direct and delayed costs of reproduction in Aesculus California. Journal of Ecology, 79, 365-378.

http://www.msnucleus.org/watersheds/mission/trees.html

http://www.calfloranursery.com/pages_plants/pages_a/aescal.html

http://www.primitiveways.com/fire_materials.html