Restoration in the Thornscrub Biome

 

I. Extent of thornscrub in North America; Biome types

Whittaker:

1) Thornwoods of arid tropical climates

2) Warm semi-desert

 
Kuchler:

1) Dsi (Broadleaf, deciduous, shrubform, frequently not touching)

2) Gdsp (Grass and broadleaf deciduous shrubform)

 
Walter:

1) Tropical with summer rains

2) Subtropical arid
 

Correl & Johnston:

1) Rio Grande plains or Tamaulipan brushlands

II. Climate

A. Dry warm-temperate and subtropical

B. Tropical climates more arid than those of seasonal forests

C. Grows adjacent to desert biomes (upslope; closer to oceanic influences)

III. Characteristics of thornscrub vegetation:

A. Spiny species of Acacia and other genera of legume are widespread

B. Small drought-deciduous leaflets

C. Succulents in more arid environments

D. Rich and diverse shrub communities

IV. Losses: grazing, brush removal, commercial plant collection, irrigated farming

 

CASE HISTORY

Lower Rio Grande Valley National Wildlife Refuge (slide show)

V. Size

    In 1995, 62,443 acres

    Proposed, 132,000 acres

VI. Two general brush habitats

A. Riparian and scrub forests (larger vegetation)

B. Upland thornscrub and thorn woodland

VII. Associated wildlife: ocelot, jaguarundi, coati, javelina, chachalaca, parrots, green jay

VIII Human impacts

A. Agricultural conversion

B. Pesticides

C. Water development

    floodway system

    Falcon and Amistad reservoirs

    pumping stations and irrigation

D. Brush removal

    mechanical

    chemical

E. Urbanization

F. Recreation

IX. Current management

A. Land purchase

B. Easements

C. Land lease and land management agreements

D. Restoration on abandoned or purchased cropland

X. Refuge strategy

A. Priority communities

B. Corridor approach

C. Anchor refugia

D. Management units

E. Control of unique terrestrial islands