Bava Batra 27: Roots and Branches Getting in the Way

How do we determine the amount of land 'belongs' to each tree?  Roots extend beneath any boundary that might be indicated at the surface of the land.  Does a tree include hundreds of cubits each?  And are these measurements to be calculated in a square shape or circularly around each tree?  And as these numbers cannot be precise, how binding could they be?

We are reminded that pe'a, leaving the corners of the land for those who are poor, and bikkurim, bringing one's first fruits to the Temple, are mitzvot that should be kept regardless of the amount of land or roots that surround a tree.  The rabbis are also concerned with prosbol, any debt that is left outstanding as the Sabbatical year begins.  

The Gemara points out that some plants, like trees, have deep and far-reaching roots as they require much from the land to nurture them.  Other plants, like wheat, require very little from the land in order to flourish.  The rabbis recognize that our halachot should be different for those who live in Eretz Yisrael and those who live elsewhere.  Only in HaAretz are people required to follow agriculturally based halachot.  Finally, we are reminded that a tree's roots are considered to affect the quality of the land for only 16 cubits beyond the tree itself. While the roots do extend further, at that point they do not damage the land.

We are introduced to a new Mishna.  It teaches about cutting the branches of a neighbour's tree.  We are permitted to cut those branches to allow a plow to move beneath those trees.  Further, we are permitted to cut the branches along the plumb line, the line that defines one's property running perpendicular to the boundary between properties.  There is an argument as to whether it is only when trees are barren or when irrigation is at stake that one is permitted to remove all of their neighbour's branches.  

A final new Mishna tells us about an argument regarding branches that hang over a public area.  Some believe that the branches should be removed so that a camel with a rider can pass beneath them.  Others believe that the branches should be removed so that a camel carrying flax can pass beneath them.  Others believe that all branches should be removed to the plumb line, at the border, due to rules of ritual impurity.

The Gemara discusses this Mishna briefly before we end both today's daf and Perek II.  First, we cannot account for future damages.  Pits could be in the public domain as well, for example.  Second, the rabbis question which is taller, a camel with a rider or camel with bundles or flax.  And couldn't a rider simply bend over when approaching these branches?  Finally, the rabbis consider the suggestion of a risk of ritual impurity.  Of course this is the problem, for branches could form a tent over a corpse beneath it, creating the opportunity for a transferring of ritual impurity to anyone/anything under that 'tent' that is susceptible.