A notable thing about famines is that they tend to cluster together. The Biblical story of Joseph and the Seven Fat Cows and the Seven Lean Cows is not atypical.
The chart shown below indicates "famine" years in Italy. Incidentally, a "famine year" was typically the second year of crop failure. Peasants and cities were intelligent enough to hold sufficient reserves to buffer against one crop failure. But two crop failures in-a-row exceeded the food reserves and created famine.
-Plagues reduced the population well below the carrying capacity of the land thus causing many decades of over-production until the population recovered
-New agricultural technologies and crop species causing a step-like increase in the carrying capacity of the land resulting in many years of over-production....until the population caught up.
-War and civil strife destroying standing crops and distracting the rural population from effectively tilling the land.
The article also implied that a high degree of plant disease inoculum for diseases like wheat rust would continue in the environment and would continue to bedevil production for many years, even after weather patterns returned to "normal".
Some regions fared better than others. Among those that fared well, according to the source sited above:
"...could make relatively ample recourse to rustic crops and to the cultivation of trees like chestnuts and olives, more resistant than wheat to the meteorological adversities..."The rural areas were historically left to fend for themselves.
"...during a severe famine the cities were clearly favoured over the rural areas, which tended to become a kind of no man’s land in which it was dangerous to venture without taking precautions - a fact which surely had also a further, damaging impact on food production..."Consequently, the rural areas were wise to armor themselves with multiple, backup food sources.
There is a very good article at the QDMA website about why it is advantageous to have "Red Oak" type trees in your plantings.
"Red oak acorns remain viable, and edible, far longer on the ground than white oak acorns. In fact, long after white oak acorns are gone or rotted, long after hunters have put their camo back in the closet and settled by the fireplace, long after fall food plots have stopped growing and corn fields have been looted, deer may still be feeding on red oak acorns if any were produced that year."
A necropsy performed on two whitetail deer that had been killed in Louisiana by a lightening strike on June 3 revealed:
"Just to be sure no other factors were involved, David (Moreland) performed a full necropsy on both deer, including a look at their stomach contents. Both deer were full of water oak acorns – in June! Here’s a photo of the sorted stomach contents of one of the deer, showing just how many acorns were found"
The pictures included in the article are impressive and I recommend you pop over and look.
So consider including oaks of the Red Oak family if it is important to you that wildlife can find a meal over a long period of time, or if you are planting oak trees as part of a "famine plan".