Rehabilitation of Degraded Grasslands in North Syria: The Use of Awassi Sheep to Disperse the Seeds of Annual Pasture Legumes

Abstract

Four experiments were conducted to facilitate the improvement of degraded grasslands in north Syria. The ®rst examined the survival of legume seeds fed to penned Awassi wethers. The second and third observed the germination and establishment of legumes from faecal pellets in the ®eld and in a glasshouse respectively. The fourth explored the possibility of transporting seeds from legume-rich (source) to legume-poor (target) grasslands using commercial¯ocks on communally-owned land. Seeds of small-seeded clovers passed through sheep in greater numbers (58± 72%) than did seeds of larger-seeded species (10±40%). Of the clover seeds Trifolium campestre (seed size 0.45 mg) disintegrated least (72% passage) and T. haussknechtii (seed size 2.68 mg) disintegrated most (10% passage). Recoveries of Medicago noeana and Scorpiurus muricatus seeds were larger than expected on the basis of their seed sizes. Maximum rate of recovery was at 36 h after the seed meal for all species, all seeds were recovered by 120 h and 90% of the recovered seeds were passed in 72 h. Ingestion had little eect on the hardness and viability of most seeds. Experiments 2 and 3 suggested that seeds in pellets germinated and established as successfully as naked seeds. Burial increased establishment, whether in the ®eld or under conditions of low moisture stress in the glasshouse. The small-seeded clovers, T. tomentosum and T. campestre, established most successfully whether from pellets or from naked seeds. About 500 seeds m 72 were successfully transported from the source to the target grassland. About half were Trigonella monspeliaca, a naturally-occurring legume found on both the source and target grasslands. Of the species sown on the source grassland, 115 seeds m 72 of Trifolium campestre (33% of the source seed bank), 62 seeds m 72 of T. tomentosum (27%) and 78 seeds m 72 of T. purpureum (21%) were detected in the target. Few medics were transported (for example, 52% of M. noeana). Apart from Trigonella monspeliaca, Trifolium tomentosum (16 plants m 72 ) was the most frequent species found in the target grassland in the following April. The results suggest that using sheep is a cheap and practical way of dispersing the seeds of pasture legumes and thereby improving the degraded grasslands of north Syria. They clearly demonstrate the role of small-seeded legumes (51 mg) in grassland improvement, especially the small-seeded clovers.

Endozoochorus seed dispersal by goats: recovery, germinability and emergence of five Mediterranean shrub species

“…The hard coat of these seeds was undoubtedly the main factor favoring recovery or otherwise, its large size could had favor its destruction during mastication and rumination, and since a negative relationship between seed size and percentage of seeds recovered after gut passage has been documented for goats (Simao Neto et al, 1987), rabbits and sheep (Staniforth & Cavers, 1977;Russi et al, 1992;Pakeman et al, 2002). The percentages of seeds retrieved of A. halimus (4%), P. angustifolia (2.7%) and R. lycioides (1.3%) were lower than those obtained for other herbaceous and shrub species eaten by domestic ruminants such as sheep (10-72%, Ghassali et al, 1998;2.3-74%, Razanamandranto et al, 2004;10-23%, Manzano et al, 2005), goats (7-30%, MancillaLeytón et al, 2011) or cattle (6.2-80%, Gardener et al, 1993). These low retrieval percentages are similar to those obtained for commercial seeds of fodder species (Moricandia arvensis, Vicia ervilia and Medicago sativa cv.…”

Germinação de sementes em placas fecais bovinas

“…O período pós-ingestão das sementes em que foram excretadas as fezes que apresentou maior porcentagem de plântulas germinadas, em relação ao somatório total de plantas germinadas em todos os intervalos (102 igual a 100%), foi o de 18 a 24 horas seguido do período de 24 a 30 horas, conforme tabela III. Estes resultados estão de acordo com os encontrados por Ghassali et al (1998) aaBB Médias seguidas, na mesma coluna por letras minúsculas iguais, e na mesma linha por letras maiúsculas iguais, não diferem entre si pelo teste de Tukey a 5% de probabilidade. *Cada valor apresentado na tabela, para espécie em cada período, representa a média de 5 repetições.…”

Endozoochorous seed dispersal by cattle and horse in a spatially heterogeneous landscape

“…A comparable use of livestock is the use of cattle and sheep as 'sowing machines' to improve grasslands (Lowry 1997;Ghassali et al 1998). In the same context we would therefore argue to consider the opportunities which arise from the movements of livestock between parcels or small nature reserves.…”