تغییرات تنوع گونه‌ای و گروه‌های کارکردی در ارتباط با چرای دام در مراتع استپی ندوشن یزد

نویسندگان

1 دانشگاه ساری

2 دانشگاه آزاد

چکیده

چرای دام یکی از عوامل مهم تأثیرگذار بر ساختار و پویایی اکوسیستم‌های مرتعی محسوب می‌شود. به همین دلیل، بررسی تأثیر چرا بر پوشش گیاهی لازم و ضروری است. در این پژوهش، از گروه‌های کارکردی پوشش گیاهی و مؤلفه‌های تنوع و غنای گونه‌ای به‌منظور پاسخ به چرای دام در شدت‌های مختلف چرایی استفاده شد. مطالعه در مراتع استپی ندوشن در استان یزد و به‌صورت ثبت درصد تاج‌پوشش گونه‌های گیاهی در سه شدت چرایی (سنگین، متوسط و سبک) صورت گرفت. نتایج این تحقیق نشان داد تیره‌های کاسنی و پروانه‌آساها، اثر معنی‌داری به شدت چرای دام نشان داده، ولی در مقابل تیرۀ گندمیان پاسخ معنی‌داری به شدت چری دام نشان ندادند. علاوه بر این، برخی گروه‌های کارکردی نظیر یک‌ساله‌ها، ژئوفیت‌ها، کاموفیت‌ها، بوته‌ای‌ها و پهن‌برگان علفی به‌طور معنی‌داری از چرای سبک به چرای سنگین کاهش پیدا کردند، درحالی‌که درصد تاج‌پوشش چند‌ساله‌ها، تروفیت‌ها و همی‌کریپتوفیت‌ها افزایش نشان دادند. نتایج دیگر این تحقیق نشان داد از سمت چرای سبک به چرای سنگین شاهد کاهش گیاهان کم‌شونده و افزایش گیاهان زیاد‌شونده هستیم. همچنین مؤلفه‌های تنوع و غنای گونه‌ای پاسخ معنی‌داری نسبت به چرای دام نشان ندادند. در نهایت، نتایج این پژوهش نشان داده است که گروه‌های کارکردی پوشش گیاهی تا حدود زیادی تحت تأثیر چرای دام قرار گرفته و در راستای گرادیان چرایی تغییر می‌کنند، بنابراین از صفاتی که بیشترین تغییر را در شدت‌های مختلف چرای دام در منطقۀ مورد مطالعه داشته‌اند، می‌توان به‌عنوان شاخصی برای مدیریت مناسب‌تر مراتع مناطق خشک استفاده کرد.

کلیدواژه‌ها


عنوان مقاله [English]

Changes of Species Diversity and Functional groups in Relation to Grazing in Rangelands of Nodushan, Yazd province

نویسندگان [English]

  • Parviz Gholami 1
  • Elham Fakhimi 2
1
2
چکیده [English]

Grazing of Livestock is one of the factors having influence on the structure and dynamics of the range land vegetation. Grazing management is a vital factor to control the intensity of the rangeland ecosystems degradation. In this study, plant functional traits and diversity and richness properties were used to assess the vegetation response to different grazing intensities. This was done in Nodushan Rangelands in Yazd province. Vegetation cover was recorded under three grazing intensities (heavy, moderate and light rates grazing). Results showed that the cover percentage of Compositeae and Papilionaceae, significantly showed a negative response to grazing intensity while Gramineae was not significantly affected by different grazing pressure. Some functional groups such as annuals, Geophytes, Chamaephytes, Shrubs and Forbs significantly reduced from light to heavy rates. On the other hands, Therophyts and hemicryptophytes were increased. The other findings of this study showed that decreaser plants significantly had less cover under heavy grazing whereas increaser plants had greater cover under heavy grazing. Also diversity and richness had no significant response to grazing intensity. The results of this research showed that plant traits may change under grazing intensity. In conclusion, we recommend using these traits that show the highest response along the grazing as intensity gradient in the arid rangelands.

کلیدواژه‌ها [English]

  • Functional groups
  • Richness species
  • Heavy grazing
  • Nodushan
  • Yazd
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