Constructions and urbanization in forests: effects on Ecosystem integrity and connectivity.

Constructions and urbanization in forests: effects on Ecosystem integrity and connectivity.

In Landscape Ecology, this kind of anthropogenic activity will result in what is called disturbance and will be considered as a major factors in breaking the original habitat and their own potential for connectivity and ecological interactions. This indeed will result in land cover type changes or might reach to enhance invaders to replace native ones.

Urbanization or constructions in its simple form at small scales will never be different from that takes place in large scales, in that, in our situation where most of these activities are choose in a densely forest areas taking advantage form the marvelous aesthetic landscape and so we are dealing with a very dense area that are covered with forest trees with its own biodiversity indices which is normally form forest ecosystem.

Urbanization deals with buildings and roads and other goods and benefits as services. Such activity in such habitat will result in

• landscape disturbance

• Fragmentation

• Habitat loss

• Edge formation

• Breaking connectivity

Effects of Disturbance

Disturbance may have one or more consequences, including:

-Total habitat destruction/extinction

-Creation of new habitat (i.e., habitat transformation or replacement)

-Habitat fragmentation (which implies habitat loss, isolation of habitat remnants, and habitat transformation)

-Increase patch numbers, isolation, edges

-Decrease patch size, breaking connectivity internally and externally.

-Alter local climate/microclimate, hydrology, and biota (in terms of diversity, behavior, health, fitness, and persistence

Microclimate effects and changes

We are dealing with temperature, humidity and light.

Light is the critical aspect that might change both temperature and humidity in either increase or decrease them, in that, plants and along habitat life integrated and adapted to a certain form of wavelengths that came from sun wither in its direct or indirect form, in forms of wavelengths which are suitable for certain forms of life represented in nature in the available species (Flora and Fauna). Buildings and roads will in turn change wavelength forms and types that came from the reflected wavelengths from the new implemented elements in the local environment due to the absorption and reflection and re-ejection of wavelengths to the atmosphere, which in turn change temperature and consequently humidity.

Such changes will result in building new habitat, and new environmental conditions which will harm the well adapted species (natives) and the entrance of new ones as invaders to such new conditions as the microclimate is the most effective in biodiversity integration.

Fragmentation as a direct impact to human interfere will takes place, as fragmentation entails three changes

• habitat loss

• isolation of habitat remnants

• habitat alteration

As a results of fragmentation:

-loss of habitat area (and since there is a strong species-area relationship, this loss means a decline in species diversity)

-Creation of another type of land cover, which may result in species replacement

-Increase habitat isolation (resulting in inbreeding)

-Increase patch edges formation (edge effect or Aldo Leopold).

-Decrease habitat connectivity

-Changes patch microclimate (and hence, soil and vegetation) à increase temperature, decrease humidity

-Slower decomposition rates (because decomposer richness decrease)

-decrease reproductive output of plants (because pollinator richness decrease)

-Increase Susceptibility of patches to disturbance (wind damage and tree mortality increase.)

-Disrupt dispersal/flows

-May promote coexistence of competitors across the entire landscape if they occupy different patches

Long term effect to such activity will result also in new edge formation. In nature, natural disturbance might cause edge formation but this form is beneficial as adaptation and integration already takes place gradually with forest growth.

In landscape Ecology, Edge is the transition zone between two distinct landscape elements.

This transition area possesses some characteristics of both landscape elements but is neither completely one nor the other. However, while it is true that some species do tend to congregate at habitat edges for a variety of reasons:

- Change in microclimate present at an edge that represents an intermediate between 2 habitat types means that a species can experience a change in conditions without necessarily being exposed to completely different conditions

- Difference in visibility (useful for both predators and prey)

• A simple unwillingness to venture out into the other habitat type while being crowded or wanting to disperse many other species tend to avoid edges.

Edges serve as access points to interior habitats for invasive/weedy species, brood parasites, and nest predators

- Organisms may experience crowding there

- Species near edges that have passively dispersed propagules (e.g. plants with wind-borne seeds, ballooning spider lings) may lose more of their propagules into unsuitable habitat

- Edges may act as "drift fences" that funnel organisms along set pathways, where they may be vulnerable to predation

- May act as "ecological traps" when species that congregate there after being attracted by a seemingly favorable microclimate or high food availability (seeds from weedy plants, insects) then suffer increased visibility to predators or brood parasites and increased vulnerability to climate extremes

However, the terms "positive" and "negative" are value-laden terms. It is far more useful to not categorize but rather to focus on what is now known about edge effects.

1) Edges do influence temperature, light availability, and moisture, which in turn influence the abundance and distribution of organisms.

2) Edge effects are species-specific: some species benefit from the creation of edges whereas others fare worse.

3) Edge effects do not extend some fixed distance into a habitat type: instead, they vary with topography, local climate, and the species being considered.

4) Species do not necessarily respond to the same type of edge in all situations: a species may not cross an edge in one location but may be perfectly happy to do so under other circumstances.

5) Edges do influence movement patterns of organisms, propagules, wind currents, and other things.

6) Not all edges are created equal: there are "soft" and "hard" edges.

Edge may act as "ecological traps" when species that congregate there after being attracted by a seemingly favorable microclimate or high food availability (seeds from weedy plants, insects) then suffer increased visibility to predators or brood parasites and increased vulnerability to climate extremes

In Dibbeen Flora Baseline Survey report, it is reported that there are 249 species that are belong to 53 families, three of these are the most important species (anacamptis pyramidalis) which has been recorded to be threatened species since the last three centuries, (iris bismarkiana) where it has been recorded firstly in 1999, and (neotinia maculate) the most rare and threatened species in Jordan.

All reports that deals with nature conservation, recommend to expand Dibbeen reserve.

For PINUS HALEPENSIS, the mean vegetative cover density is 72 tree/ donum, and as a simple measurement we can see that:

Assume that the area of each residential unit = 100 meter square

Which means that there are 7.2 trees to be removed?

So, let us assume to have 210 residential units inside one forest

7.2 * 210= 1512 trees must be removed

Environmentally speaking, the value of each adult tree = 10000 JD

The net removal cost for the residential units = 1512 * 10000 = 15,120,000 JD

For building one Hotel:

Assume that the hotel area 50*50m = 2500 square meter

2.5 * 72 = 180 tree

180*10000 = 1,800,000 JD

For the other services 180 tree to be removed

= 1,800,000 JD