The Effects of Long Time Conservation of Heavily Grazed Shrubland: A Case Study in the Northern Negev, Israel

Abstract

One of the major reasons for desertification is unrestricted grazing leading to vegetation depletion, soil erosion and degradation, phenomena often considered irreversible in the short term. Here, we compare soil and biological parameters of degraded and conserved, recently rehabilitated arid shrubland in the Northern Negev, Israel. The study area was restored by conservation efforts including a strictly controlled grazing regime initiated in 1992. The visually recognizable improvement in the ecology of the restored shrubland is reflected in significant improvement in all examined biotic (herbaceous biomass, shrub patch density, and insect activity), and soil parameters (nutrients, organic matter content, moisture, and water infiltration). The difference is created predominantly by restoration of large biological patches composed of shrubs and other perennial plants often associated with ant or termite nests, where the most significant increases in productivity and soil quality were observed. In the conserved shrubland such patches covered 35 or 25 % of the area (in a normal and a drought year, respectively). In the degraded shrubland 5 % or less of the area was occupied by such patches that were much smaller and of lower biological complexity. With respect to plant biodiversity, six plant species were found only—and 18 others became significantly more common—in the rehabilitated area. The results of this article indicate that functional arid drylands can be restored within <16 years relying on strict conservation management with reduced grazing intensity.

Appendix

Absence: The species is absent from the studied shrubland (Grazed or Conserved).

Rare: The species appears in one plot in the studied shrubland (from “up,” “middle,” and “down” plots, Fig. 1).

Common: The species appears in two or three plots in the studied shrubland.

	Latinist name	Conserved	Grazed
Forbs
1	Adonis dentata	Rare	Common
2	Anagallis arvensis	Absence	Rare
3	Arnebia decumbens	Rare	Rare
4	Artemisia crassifolia	Rare	Absence
5	Asteriscus pygmaeus	Common	Common
6	Astragalus cretaceus	Rare	Common
7	Astragalus tribuloides	Common	Absence
8	Bupleurum nodiflorum	Absence	Rare
9	Carthamus tenuis	Common	Common
10	Centauria hyalolepis	Common	Common
11	Cnicus beneficus	Rare	Rare
12	Dianthus strictus	Common	Rare
13	Echinops polyceras	Common	Absence
14	Filago contracta	Rare	Rare
15	Gundelia tourneforti	Common	Common
16	Heliotropium europaeum	Rare	Rare
17	Helianthemum lediflorum	Rare	Absence
18	Herniaria hirsuta	Absence	Rare
19	Hippocrepis unisiliquosa	Rare	Rare
20	Hymenocarpos circinnatus	Rare	Absence
21	Hormuzakia aggregata	Common	Absence
22	Medicago laciniata	Common	Rare
23	Neotorularia torulosa	Rare	Rare
24	Onobrychis cristata	Rare	Common
25	Paronychia argentea	Rare	Absence
26	Plantago coronopus	Absence	Common
27	Pterocephalus brevis	Absence	Rare
28	Reboudia pinnata	Rare	Rare
29	Roemeria hybrida	Absence	Rare
Shrubs
30	Atractylis serratuloides	Rare	Rare
31	Helianthemum ventosum	Rare	Absence
32	Noaea mucronata	Rare	Absence
33	Phagnalon rupestre	Common	Absence
Cryptophytes
34	Allium stamineum	Common	Rare
35	Asphodelus racemosus	Rare	Common
36	Carex pachystyla	Common	Common
37	Gynandriris sisyrhinchium	Common	Common
38	Scorzonera papposa	Rare	Rare
Hemi cryptophytes
39	Astragalus cichrous	Common	Rare
40	Gypsophila arabica	Rare	Rare
41	Eryngium creticum	Rare	Rare
42	Salvia lanigera	Absence	Rare
Graminoids
43	Avena barbata	Common	Absence
44	Broumus fasciculatus	Rare	Absence
45	Convolvulus lanatus	Rare	Absence
46	Rostraria cristata	Rare	Absence
47	Schismus arabicus	Common	Common
48	Stipa capensis	Common	Common
49	Vulpia ciliaris	Absence	Rare