REGENERATION THROUGH RESPROUTING AFTER CLEAR-CUTTING AND TOPSOIL STRIPPING IN A TROPICAL DRY FOREST IN CENTRAL BRAZIL1

ABSTRACT Tropical dry forest trees have high resprouting ability, which may be useful for ecological restoration purposes. However, resprouting ability is affected by the type and severity of the disturbance. This study described the regeneration of trees through resprouting in a seasonally deciduous forest in Central Brazil, six months after being subjected to a gradient of disturbance. In order to expand a limestone quarry, 10 ha of deciduous forest were deforested in May 2013, creating areas with three increasing levels of disturbance: Clear-Cutting, Stump Removal and 5-20 cm of Topsoil Stripping. Twenty 3.14 m² circular plots were randomly selected in each type of disturbance. All resprouts were counted and identified to species level. The plant organ where each resprout grew from and the distance of the resprout insertion to the soil were recorded. There were 27 species in the Clear-Cutting and Stump Removal areas, and 24 in the Topsoil Stripping site. Resprout density was 3.0 ± 0.3a/m² in the Clear-Cutting, 1.7 ± 0.4b in the Stump Removal and 1.4 ± 0.4b in the Topsoil Stripping area (mean ± SD; Tukey HSD). Stems contributed to 61% of the resprouts in the Clear-Cutting area, while 60% of the resprouts in Stump Removal grew from root collars and 70% of the resprouts in Topsoil Stripping grew from roots. Underground resprouts emerged from a depth of up to 24 cm. An increase in disturbance severity negatively affected resprouting ability, but natural regeneration was high regardless of disturbance severity. The high resprouting ability of the deciduous forest trees provides resilience even after topsoil stripping.

摘要：热带旱生林木具有较强的萌蘖能力（resprouting ability），该特性可用于生态修复实践。然而，林木的萌蘖能力会受到干扰类型与干扰强度的影响。本研究针对巴西中部一处季节性落叶林，调查了其在经受梯度干扰6个月后的树木萌蘖更新状况。
为扩建石灰岩采石场，研究团队于2013年5月对10公顷落叶林实施清伐作业，以此设置了3个梯度递增的干扰处理组：皆伐（Clear-Cutting）、伐桩移除（Stump Removal）以及5-20厘米表土剥离（Topsoil Stripping）。在每种干扰处理区中，随机布设20个面积为3.14 m²的圆形样地。对所有萌蘖株进行计数，并鉴定至物种水平。同时记录每株萌蘖的起源器官，以及萌蘖着生点距土壤表面的距离。
皆伐与伐桩移除样地共记录到27个物种，表土剥离样地则记录到24个物种。皆伐区的萌蘖密度为3.0 ± 0.3a /m²，伐桩移除区为1.7 ± 0.4b，表土剥离区为1.4 ± 0.4b（数据为平均值±标准差；组间差异经图基HSD检验（Tukey HSD））。皆伐区中61%的萌蘖株起源于茎干，伐桩移除区60%的萌蘖株起源于根颈，而表土剥离区70%的萌蘖株起源于根系。地下萌蘖的着生深度可达24厘米。
干扰强度的升高会对林木萌蘖能力产生负面影响，但无论干扰强度如何，该森林的自然更新率均处于较高水平。落叶林木的强萌蘖能力，即便在表土剥离的干扰下，仍能为生态系统提供恢复力。