About forest farming

here are some info. on forest farming for your reading.

Introduction:
Forest farming practices can be used by private enterprise to grow desirable non-timber forest products on private lands, to supplement family income, and to allow biodiversity to reestablish within forests.

Definition:
Special forest products (SFPs) or non-timber forest products (NTFPs) are high-value specialty product items derived from green plants, fungi, invertebrates, and other organisms that inhabit forested areas.

These products fall into four general categories

1. food (e.g., mushrooms and nuts)
2. botanicals (e.g., herbs and medicinals - tongkat ali, ginseng, kacip fatimah)
3. decoratives (e.g., floral greenery and dyes)
4. handicrafts (e.g., baskets and wood products -rattan)

Concepts & Principles:

In forest farming practices, high-value specialty crops are intentionally cultivated under the protection of a forest overstory that has been modified and managed to provide the appropriate microclimate conditions.

Typically, these systems are established on private land by thinning an existing forest or woodlot to leave the best crop trees for continued wood production and to create the appropriate conditions for the understory crop to be grown.

Then, the understory crop is established and intensively managed to provide short-term income.

Planning & Design:

A forest farming practice is usually a small area of land (5 acres or less) whose vertical, horizontal, and below-ground dimensions are managed intensely to produce multiple crops simultaneously.

Systems usually focus on a single SFP plus timber, but can include several products.

Examples of systems include:

1. ginseng + maple syrup + bee products + timber
2. shiitake mushrooms + timber
3. ferns + beargrass + mushrooms + timber
4. ginseng + walnuts + black walnut veneer logs

The amount of light in the stands is altered by thinning, pruning, or adding trees.
Existing stands of trees can be intercropped with annual, perennial, or woody plants. Compatibility among understory and overstory plants and cultural methods is essential.

Benefits:

1. Economic
   Some products especially medicinals and botanicals can have tremendous economic value, while others provide a lower but steady supplemental income.
   
2. Conservation and System-Level
   Forest farming activities modify the forest ecosystem but do not significantly interfere with its crucial contributions of water capture and filtering, soil erosion control, microclimate moderation, and wildlife habitat.
   Producers should avoid harmful species and follow EPA approved guidelines for herbicides, fungicides, and insecticides.
   
3. Social
   Forest farming provides opportunities to generate short-term income from existing woodlots,with minimum capital investment. Especially on small family farms, this can contribute significantly to rural economic development and diversification.

source: forest farming - An Agroforestry Practice .

Mitosis and Meiosis

Image shows karyotype of a female. Her somatic cell has a diploid number of 46.

refer to your chapter 5 note.
What is diploid number & haploid number of chromosome?
1. Diploid - organisms or cells that have 2 sets of chromosomes.
2. Haploid - cells that have only one set of chromosomes.

Here are some images which are related to cell division:

1. Image below shows the chromosomes, DNA, histone proteins inside the nucleus of a typical cell.

2. Image below shows chromosomes.

• When the chromosome condense, coil-up and tighten during prophase of mitosis (or prophase I or prohase II of meiosis), the chromosome appear as two identical chromatids called sister chromatids attached together at the contromere.
  
  

3. Prophase I of meiosis I.

• At the chiasma, exchange of genetic material between the non-sister chromatids of bivalent through the process of crossing over.
• Crossing over results in new combination of genetic material and is important source of genetic variation.
  

4. the differences between Meiosis & Mitosis

Plant Hormone

what is coleoptile? it is a tough protective sheath that encloses/protects the tip of a shoot.

• refer to page 22-24, chapter 3.
  
• Plant hormone is a chemical substance produced by plant, which is able to influence the growth & development of the plant.
  
• Plant hormones can be used to produce fruit without seeds, to ripen fruits, to increase the size of fruit, in growing cuttings, controlling weeds, etc.
  
• There are 5 classes of plant hormone:
  1. Auxins (Indole Acetic Acid) - promotes cell elongation at stem tip, roots initiation, fruit development.
  2. Cytokinins - promotes cell division
  3. Gibberellins - promotes cell elongation
  4. Abscisic acid - promotes seed dormancy
  5. Ethylene (ethene) - a gas hormone which is used to ripen fruits, etc
  
• Auxin is a plant hormone that controls tropic response.
• It is produced in the apical meristem of the shoot & root.
• Auxin diffuse from zone of cell division into zone of cell elongation where it stimulates the cell to elongate.
  
• Diagram below shows:
  1. concentration of auxins needed for maximum growth of shoots will inhibit roots growth.
  2. at low concentration of auxin hormone, this promotes roots growth but cannot stimulate shoots growth.
  
  

Below are some experiments related to Auxins hormone:

1. The coleoptile tip is removed (just above the zone of cell elongation). Gelatin/agar block which contains auxin hormone is then placed at one side of the coleoptile.
Results: coleoptile bending towards the side without the agar block.

2. Role of auxins in controlling phototropism: (unilateral light)

3. Shoot placed horizontally. Auxin hormone will accumulate at the lower side.

4. Diagram below showing geotropism on shoot & root of seedling when the seedlings are placed in different positions. The shoot shows negative geotropism while the root shows positive geotropism.