Compare and contrast their different subjects, specialties and approaches:

Carson -- places where indicator species dwell are clear signals of exising or ambient conditions
Van der Ryn -- A Journal of remembered designs in places, for people and events.
McHarg -- A collection of essays defining places, time, layered features, specifics and plans.
Siry -- a geographical, ecological, cultural and legal description of coastal water bodies. (places)

Land is not merely a section of earth or an expanse of territory, or a disturbed real-estate parcel..

Why? Because

Van der Ryn says the Earth and its varied landscapes make up a fickle, yet constant medium of expression for works of human engineering, architecture and design..
McHarg says land is a layered landscape comprised of a geological and a human prehistory that can often be deciphered from clues left behind by glaciers, erosion, vegetation, & past occupants.
Siry explains that with respect to the coast's least appreciated parcels, human ideas about estuarine marshes, waters and landscapes have undergone dramatic changes in three centuries.

Ecogically

McHarg explains the importance of knowledge of natural features like dunes.

What about gardens?

Don't they have literal, figurative and proverbial meaning for us?

• Literally, they are planted areas with domesticated or wild specimens we can eat or admire.
  
• Figuratively, any garden is a creation where people use water, elements, & features to grow things.
  
• Proverbially, gardens are the source of Judeo-Christian & Islamic creation, fall and redemption.
• Mcharg insists that we need to create experimental plots, mesocosms to compare our's and nature's priorities.

How to go about setting priorites.

Assumptions.

Conside that the word Weal has an etymology that reveals the importance of trees or forests, we can conclude that places may be more than the mere sums of their respective parts.

Hence: any place or places are made up of: water, energy. air, land and a related set of dimensions.

Identifying natural values.

key idea.