Context

The Dry Chaco spans more than 87 million hectares across Argentina, Bolivia, and Paraguay. This unique forest system has experienced extensive loss and fragmentation due to land-use change, with different land-use histories in the three countries. This forest loss has altered landscape connectivity for the Dry Chaco’s associated biota.

Objectives

We compared patterns of deforestation-induced fragmentation and concomitant changes in structural landscape connectivity between 2000 and 2019 in the three countries to identify consistent patterns that might facilitate biome-wide conservation.

Methods

We quantified forest cover in the Dry Chaco of Argentina, Bolivia, and Paraguay for the years 2000 and 2019 at 30 m resolution. We analyzed structural connectivity at three scales. Then, we identified and visualized the most important stepping stones per country per year.

Results

Between 2000 and 2019, the overall extent of Dry Chaco forest cover decreased by 20.2% (9.5 million ha). All three counties experienced substantial reductions, with Paraguay undergoing the greatest loss and fragmentation relative to 2000. Most of the overall network metrics decreased from 2000 to 2019 for Paraguay and Bolivia, but Argentina experienced increased coalescence distance and average nodal connectance. Dispersal-level metrics showed clustering threshold distances between 1000 and 2000 m for each country in both years.

Conclusions

The large number of forest fragments and distances between them suggest that some mammals characteristic of the biome may be experiencing negative impacts from this fragmentation. Contemporary and future challenges of uncoordinated national conservation and management policies, land speculation, and increased human infrastructure will accelerate the rate of deforestation.

中文翻译：

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消失的干查科，地球上最后的干旱森林系统之一

语境

Dry Chaco 横跨阿根廷、玻利维亚和巴拉圭，占地超过 8700 万公顷。由于土地利用的变化，这个独特的森林系统经历了广泛的丧失和破碎，三个国家的土地利用历史不同。这种森林消失改变了干查科相关生物群的景观连通性。

目标

我们比较了 2000 年至 2019 年这三个国家的森林砍伐导致的破碎化模式和结构景观连通性的伴随变化，以确定可能促进生物群落保护的一致模式。

方法

我们以 30 m 的分辨率量化了 2000 年和 2019 年阿根廷、玻利维亚和巴拉圭干查科地区的森林覆盖率。我们分析了三个尺度的结构连通性。然后，我们确定并可视化了每个国家/地区每年最重要的垫脚石。

结果

2000 年至 2019 年期间，干查科森林覆盖的总体范围减少了 20.2%（950 万公顷）。所有三个县都经历了大幅减少，相对于 2000 年，巴拉圭经历了最大的损失和碎片化。巴拉圭和玻利维亚的大部分整体网络指标从 2000 年到 2019 年都有所下降，但阿根廷的合并距离和平均节点连接度有所增加。散布水平指标显示，两个国家/地区的聚类阈值距离都在 1000 到 2000 米之间。

结论

大量的森林碎片和它们之间的距离表明，生物群落特征的一些哺乳动物可能正在经历这种碎片化的负面影响。不协调的国家保护和管理政策、土地投机和人类基础设施增加的当代和未来挑战将加速森林砍伐的速度。